Patent Publication Number: US-2022232313-A1

Title: Acoustic port for a playback device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Patent Application No. 63/199,716, filed Jan. 19, 2021, which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure is related to consumer goods and, more particularly, to methods, systems, products, features, services, and other elements directed to media playback or some aspect thereof. 
     BACKGROUND 
     Options for accessing and listening to digital audio in an out-loud setting were limited until in 2002, when SONOS, Inc. began development of a new type of playback system. Sonos then filed one of its first patent applications in 2003, entitled “Method for Synchronizing Audio Playback between Multiple Networked Devices,” and began offering its first media playback systems for sale in 2005. The Sonos Wireless Home Sound System enables people to experience music from many sources via one or more networked playback devices. Through a software control application installed on a controller (e.g., smartphone, tablet, computer, voice input device), one can play what she wants in any room having a networked playback device. Media content (e.g., songs, podcasts, video sound) can be streamed to playback devices such that each room with a playback device can play back corresponding different media content. In addition, rooms can be grouped together for synchronous playback of the same media content, and/or the same media content can be heard in all rooms synchronously. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, examples, and advantages of the presently disclosed technology may be better understood with regard to the following description, appended claims, and accompanying drawings, as listed below. A person skilled in the relevant art will understand that the features shown in the drawings are for purposes of illustrations, and variations, including different and/or additional features and arrangements thereof, are possible. 
         FIG. 1A  is a partial cutaway view of an environment having a media playback system configured in accordance with examples of the disclosed technology. 
         FIG. 1B  is a schematic diagram of the media playback system of  FIG. 1A  and one or more networks. 
         FIG. 1C  is a block diagram of a playback device. 
         FIG. 1D  is a block diagram of a playback device. 
         FIG. 1E  is a block diagram of a network microphone device. 
         FIG. 1F  is a block diagram of a network microphone device. 
         FIG. 1G  is a block diagram of a playback device. 
         FIG. 1H  is a partially schematic diagram of a control device. 
         FIG. 2A  is a front isometric view of a playback device configured in accordance with examples of the disclosed technology. 
         FIG. 2B  is a front isometric view of the playback device of  FIG. 3A  without a grille. 
         FIG. 2C  is an exploded view of the playback device of  FIG. 2A . 
         FIG. 3A  is a perspective view of a playback device configured in accordance with examples of the disclosed technology. 
         FIG. 3B  is an exploded view of the playback device of  FIG. 3A  with some components hidden. 
         FIG. 3C  a top view of the playback device of  FIG. 3A  with some components hidden. 
         FIG. 4A  is a front isometric view of an acoustic port in accordance with examples of the disclosed technology. 
         FIG. 4B  is an isometric sectional view of the acoustic port from  FIG. 4A   
         FIG. 4C  is a top sectional view of the acoustic port from  FIG. 4A . 
         FIG. 5  a front isometric view of an acoustic port in accordance with examples of the disclosed technology. 
         FIG. 6  a rear isometric view of an acoustic port coupled to a frame in accordance with examples of the disclosed technology. 
     
    
    
     The drawings are for the purpose of illustrating example examples, but those of ordinary skill in the art will understand that the technology disclosed herein is not limited to the arrangements and/or instrumentality shown in the drawings. 
     DETAILED DESCRIPTION 
     I. Overview 
     Conventional playback devices can include an enclosure with an acoustic port, such as a bass reflex port. These ports can take the form of tube-like structures coupled to the enclosure, with a first end that opens to the exterior of the enclosure and a second opening that opens to the interior volume of the enclosure. As a result, the interior volume of the enclosure is fluidically coupled with the exterior environment via the port. During audio playback, air can oscillate between moving into the enclosure through the port and out of the enclosure through the port based on movement of the transducer(s) of the playback device. This oscillation can have a resonant frequency that depends on the effective length and cross-sectional area of the port and the interior volume of the enclosure. By tailoring the resonant frequency to a desired value, the bass playback of the playback device can be augmented, for example by increasing the bass response, lowering a frequency range of the bass response, and/or improving the efficiency of playback of bass content. 
     Conventional acoustic ports often have a straight tubular design. While this design is simple, the straight and tube-like design of the port may not be practical for all playback devices. For example, in playback devices with a relatively compact form-factor, such as a soundbar, a bass reflex port with a straight tubular design may be too large to fit within the playback device. Moreover, using an improperly sized port (e.g., having an effective length and/or cross-sectional area that are not suitable for the particular playback device) can result in undesirable noise and poor bass response. As such, acoustic ports cannot simply be scaled down to fit within smaller enclosures without adversely affecting acoustic performance. Accordingly, bass reflex ports are usually reserved for use in playback devices that are large enough in size to accommodate a straight port having the appropriate dimensions (e.g., length and cross-sectional area). 
     Examples of the present technology provide a bass reflex port that can be used even in playback devices having a smaller form-factor. For example, the bass reflex port can have its overall shape modified from a straight configuration to a curved or bent shape. A curved shape allows for the bass reflex port to have the same key dimensions as a properly sized bass reflex port (e.g., cross-sectional area, volume, effective length) while being amenable to fitting within a more compact enclosure than a straight tube-like design. This compact size allows for the bass reflex port to fit into playback devices with different form-factors, such as a soundbar, while still being tuned properly for the playback device. 
     Utilizing a curved bass reflex port can present some drawbacks, however. Under ideal conditions, air flow within a port is substantially laminar. However, air flowing within the curved port can become turbulent and non-uniform, which can create unwanted noise within the playback device. To reduce, minimize, and/or eliminate this noise, a curved bass reflex port can include one or more vanes positioned within the port. These vanes can divide the bass reflex port into one or more channels, which allows for the air flow through the channels to be more uniform and exhibit laminar flow characteristics. With the air exhibiting uniform, laminar, or both uniform and laminar flow characteristics, the unwanted noise caused by the curvature of the port can be reduced, minimized, or eliminated. As such, the present technology provides an acoustic port that is suitable for use in relatively compact playback devices while reducing the noise that otherwise accompanies curved acoustic ports. 
     While some examples described herein may refer to functions performed by given actors such as “users,” “listeners,” and/or other entities, it should be understood that this is for purposes of explanation only. The claims should not be interpreted to require action by any such example actor unless explicitly required by the language of the claims themselves. 
     In the Figures, identical reference numbers identify generally similar, and/or identical, elements. To facilitate the discussion of any particular element, the most significant digit or digits of a reference number refers to the Figure in which that element is first introduced. For example, element  110   a  is first introduced and discussed with reference to  FIG. 1A . Many of the details, dimensions, angles and other features shown in the Figures are merely illustrative of particular examples of the disclosed technology. Accordingly, other examples can have other details, dimensions, angles and features without departing from the spirit or scope of the disclosure. In addition, those of ordinary skill in the art will appreciate that further examples of the various disclosed technologies can be practiced without several of the details described below. 
     II. Suitable Operating Environment 
       FIG. 1A  is a partial cutaway view of a media playback system  100  distributed in an environment  101  (e.g., a house). The media playback system  100  comprises one or more playback devices  110  (identified individually as playback devices  110   a - n ), one or more network microphone devices (“NMDs”),  120  (identified individually as NMDs  120   a - c ), and one or more control devices  130  (identified individually as control devices  130   a  and  130   b ). 
     As used herein the term “playback device” can generally refer to a network device configured to receive, process, and output data of a media playback system. For example, a playback device can be a network device that receives and processes audio content. In some examples, a playback device includes one or more transducers or speakers powered by one or more amplifiers. In other examples, however, a playback device includes one of (or neither of) the speaker and the amplifier. For instance, a playback device can comprise one or more amplifiers configured to drive one or more speakers external to the playback device via a corresponding wire or cable. 
     Moreover, as used herein the term NMD (i.e., a “network microphone device”) can generally refer to a network device that is configured for audio detection. In some examples, an NMD is a stand-alone device configured primarily for audio detection. In other examples, an NMD is incorporated into a playback device (or vice versa). 
     The term “control device” can generally refer to a network device configured to perform functions relevant to facilitating user access, control, and/or configuration of the media playback system  100 . 
     Each of the playback devices  110  is configured to receive audio signals or data from one or more media sources (e.g., one or more remote servers, one or more local devices) and play back the received audio signals or data as sound. The one or more NMDs  120  are configured to receive spoken word commands, and the one or more control devices  130  are configured to receive user input. In response to the received spoken word commands and/or user input, the media playback system  100  can play back audio via one or more of the playback devices  110 . In certain examples, the playback devices  110  are configured to commence playback of media content in response to a trigger. For instance, one or more of the playback devices  110  can be configured to play back a morning playlist upon detection of an associated trigger condition (e.g., presence of a user in a kitchen, detection of a coffee machine operation). In some examples, for instance, the media playback system  100  is configured to play back audio from a first playback device (e.g., the playback device  110   a ) in synchrony with a second playback device (e.g., the playback device  110   b ). Interactions between the playback devices  110 , NMDs  120 , and/or control devices  130  of the media playback system  100  configured in accordance with the various examples of the disclosure are described in greater detail below. 
     In the illustrated example of  FIG. 1A , the environment  101  comprises a household having several rooms, spaces, and/or playback zones, including (clockwise from upper left) a master bathroom  101   a , a master bedroom  101   b , a second bedroom  101   c , a family room or den  101   d , an office  101   e , a living room  101   f , a dining room  101   g , a kitchen  101   h , and an outdoor patio  101   i . While certain examples are described below in the context of a home environment, the technologies described herein may be implemented in other types of environments. In some examples, for instance, the media playback system  100  can be implemented in one or more commercial settings (e.g., a restaurant, mall, airport, hotel, a retail or other store), one or more vehicles (e.g., a sports utility vehicle, bus, car, a ship, a boat, an airplane), multiple environments (e.g., a combination of home and vehicle environments), and/or another suitable environment where multi-zone audio may be desirable. 
     The media playback system  100  can comprise one or more playback zones, some of which may correspond to the rooms in the environment  101 . The media playback system  100  can be established with one or more playback zones, after which additional zones may be added, or removed to form, for example, the configuration shown in  FIG. 1A . Each zone may be given a name according to a different room or space such as the office  101   e , master bathroom  101   a , master bedroom  101   b , the second bedroom  101   c , kitchen  101   h , dining room  101   g , living room  101   f , and/or the balcony  101   i . In some examples, a single playback zone may include multiple rooms or spaces. In certain examples, a single room or space may include multiple playback zones. 
     In the illustrated example of  FIG. 1A , the master bathroom  101   a , the second bedroom  101   c , the office  101   e , the living room  101   f , the dining room  101   g , the kitchen  101   h , and the outdoor patio  101   i  each include one playback device  110 , and the master bedroom  101   b  and the den  101   d  include a plurality of playback devices  110 . In the master bedroom  101   b , the playback devices  110   l  and  110   m  may be configured, for example, to play back audio content in synchrony as individual ones of playback devices  110 , as a bonded playback zone, as a consolidated playback device, and/or any combination thereof. Similarly, in the den  101   d , the playback devices  110   h - j  can be configured, for instance, to play back audio content in synchrony as individual ones of playback devices  110 , as one or more bonded playback devices, and/or as one or more consolidated playback devices. Additional details regarding bonded and consolidated playback devices are described below with respect to  FIGS. 1B and 1E . 
     In some examples, one or more of the playback zones in the environment  101  may each be playing different audio content. For instance, a user may be grilling on the patio  101   i  and listening to hip hop music being played by the playback device  110   c  while another user is preparing food in the kitchen  101   h  and listening to classical music played by the playback device  110   b . In another example, a playback zone may play the same audio content in synchrony with another playback zone. For instance, the user may be in the office  101   e  listening to the playback device  110   f  playing back the same hip-hop music being played back by playback device  110   c  on the patio  101   i . In some examples, the playback devices  110   c  and  110   f  play back the hip hop music in synchrony such that the user perceives that the audio content is being played seamlessly (or at least substantially seamlessly) while moving between different playback zones. Additional details regarding audio playback synchronization among playback devices and/or zones can be found, for example, in U.S. Pat. No. 8,234,395 entitled, “System and method for synchronizing operations among a plurality of independently clocked digital data processing devices,” which is incorporated herein by reference in its entirety. 
     a. Suitable Media Playback System 
       FIG. 1B  is a schematic diagram of the media playback system  100  and a cloud network  102 . For ease of illustration, certain devices of the media playback system  100  and the cloud network  102  are omitted from  FIG. 1B . One or more communication links  103  (referred to hereinafter as “the links  103 ”) communicatively couple the media playback system  100  and the cloud network  102 . 
     The links  103  can comprise, for example, one or more wired networks, one or more wireless networks, one or more wide area networks (WAN), one or more local area networks (LAN), one or more personal area networks (PAN), one or more telecommunication networks (e.g., one or more Global System for Mobiles (GSM) networks, Code Division Multiple Access (CDMA) networks, Long-Term Evolution (LTE) networks, 5G communication network networks, and/or other suitable data transmission protocol networks), etc. The cloud network  102  is configured to deliver media content (e.g., audio content, video content, photographs, social media content) to the media playback system  100  in response to a request transmitted from the media playback system  100  via the links  103 . In some examples, the cloud network  102  is further configured to receive data (e.g. voice input data) from the media playback system  100  and correspondingly transmit commands and/or media content to the media playback system  100 . 
     The cloud network  102  comprises computing devices  106  (identified separately as a first computing device  106   a , a second computing device  106   b , and a third computing device  106   c ). The computing devices  106  can comprise individual computers or servers, such as, for example, a media streaming service server storing audio and/or other media content, a voice service server, a social media server, a media playback system control server, etc. In some examples, one or more of the computing devices  106  comprise modules of a single computer or server. In certain examples, one or more of the computing devices  106  comprise one or more modules, computers, and/or servers. Moreover, while the cloud network  102  is described above in the context of a single cloud network, in some examples the cloud network  102  comprises a plurality of cloud networks comprising communicatively coupled computing devices. Furthermore, while the cloud network  102  is shown in  FIG. 1B  as having three of the computing devices  106 , in some examples, the cloud network  102  comprises fewer (or more than) three computing devices  106 . 
     The media playback system  100  is configured to receive media content from the networks  102  via the links  103 . The received media content can comprise, for example, a Uniform Resource Identifier (URI) and/or a Uniform Resource Locator (URL). For instance, in some examples, the media playback system  100  can stream, download, or otherwise obtain data from a URI or a URL corresponding to the received media content. A network  104  communicatively couples the links  103  and at least a portion of the devices (e.g., one or more of the playback devices  110 , NMDs  120 , and/or control devices  130 ) of the media playback system  100 . The network  104  can include, for example, a wireless network (e.g., a WiFi network, a Bluetooth, a Z-Wave network, a ZigBee, and/or other suitable wireless communication protocol network) and/or a wired network (e.g., a network comprising Ethernet, Universal Serial Bus (USB), and/or another suitable wired communication). As those of ordinary skill in the art will appreciate, as used herein, “WiFi” can refer to several different communication protocols including, for example, Institute of Electrical and Electronics Engineers (IEEE) 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.11ac, 802.11ad, 802.11af, 802.11ah, 802.11ai, 802.11aj, 802.11aq, 802.11ax, 802.11ay, 802.15, etc. transmitted at 2.4 Gigahertz (GHz), 5 GHz, and/or another suitable frequency. 
     In some examples, the network  104  comprises a dedicated communication network that the media playback system  100  uses to transmit messages between individual devices and/or to transmit media content to and from media content sources (e.g., one or more of the computing devices  106 ). In certain examples, the network  104  is configured to be accessible only to devices in the media playback system  100 , thereby reducing interference and competition with other household devices. In other examples, however, the network  104  comprises an existing household communication network (e.g., a household WiFi network). In some examples, the links  103  and the network  104  comprise one or more of the same networks. In some examples, for example, the links  103  and the network  104  comprise a telecommunication network (e.g., an LTE network, a 5G network). Moreover, in some examples, the media playback system  100  is implemented without the network  104 , and devices comprising the media playback system  100  can communicate with each other, for example, via one or more direct connections, PANs, telecommunication networks, and/or other suitable communication links. 
     In some examples, audio content sources may be regularly added or removed from the media playback system  100 . In some examples, for instance, the media playback system  100  performs an indexing of media items when one or more media content sources are updated, added to, and/or removed from the media playback system  100 . The media playback system  100  can scan identifiable media items in some or all folders and/or directories accessible to the playback devices  110 , and generate or update a media content database comprising metadata (e.g., title, artist, album, track length) and other associated information (e.g., URIs, URLs) for each identifiable media item found. In some examples, for instance, the media content database is stored on one or more of the playback devices  110 , network microphone devices  120 , and/or control devices  130 . 
     In the illustrated example of  FIG. 1B , the playback devices  110   l  and  110   m  comprise a group  107   a . The playback devices  110   l  and  110   m  can be positioned in different rooms in a household and be grouped together in the group  107   a  on a temporary or permanent basis based on user input received at the control device  130   a  and/or another control device  130  in the media playback system  100 . When arranged in the group  107   a , the playback devices  110   l  and  110   m  can be configured to play back the same or similar audio content in synchrony from one or more audio content sources. In certain examples, for instance, the group  107   a  comprises a bonded zone in which the playback devices  110   l  and  110   m  comprise left audio and right audio channels, respectively, of multi-channel audio content, thereby producing or enhancing a stereo effect of the audio content. In some examples, the group  107   a  includes additional playback devices  110 . In other examples, however, the media playback system  100  omits the group  107   a  and/or other grouped arrangements of the playback devices  110 . 
     The media playback system  100  includes the NMDs  120   a  and  120   d , each comprising one or more microphones configured to receive voice utterances from a user. In the illustrated example of  FIG. 1B , the NMD  120   a  is a standalone device and the NMD  120   d  is integrated into the playback device  110   n . The NMD  120   a , for example, is configured to receive voice input  121  from a user  123 . In some examples, the NMD  120   a  transmits data associated with the received voice input  121  to a voice assistant service (VAS) configured to (i) process the received voice input data and (ii) transmit a corresponding command to the media playback system  100 . In some examples, for instance, the computing device  106   c  comprises one or more modules and/or servers of a VAS (e.g., a VAS operated by one or more of SONOS®, AMAZON®, GOOGLE® APPLE®, MICROSOFT®). The computing device  106   c  can receive the voice input data from the NMD  120   a  via the network  104  and the links  103 . In response to receiving the voice input data, the computing device  106   c  processes the voice input data (i.e., “Play Hey Jude by The Beatles”), and determines that the processed voice input includes a command to play a song (e.g., “Hey Jude”). The computing device  106   c  accordingly transmits commands to the media playback system  100  to play back “Hey Jude” by the Beatles from a suitable media service (e.g., via one or more of the computing devices  106 ) on one or more of the playback devices  110 . 
     b. Suitable Playback Devices 
       FIG. 1C  is a block diagram of the playback device  110   a  comprising an input/output  111 . The input/output  111  can include an analog I/O  111   a  (e.g., one or more wires, cables, and/or other suitable communication links configured to carry analog signals) and/or a digital I/O  111   b  (e.g., one or more wires, cables, or other suitable communication links configured to carry digital signals). In some examples, the analog I/O  111   a  is an audio line-in input connection comprising, for example, an auto-detecting 3.5 mm audio line-in connection. In some examples, the digital I/O  111   b  comprises a Sony/Philips Digital Interface Format (S/PDIF) communication interface and/or cable and/or a Toshiba Link (TOSLINK) cable. In some examples, the digital I/O  111   b  comprises a High-Definition Multimedia Interface (HDMI) interface and/or cable. In some examples, the digital I/O  111   b  includes one or more wireless communication links comprising, for example, a radio frequency (RF), infrared, WiFi, Bluetooth, or another suitable communication protocol. In certain examples, the analog I/O  111   a  and the digital  111   b  comprise interfaces (e.g., ports, plugs, jacks) configured to receive connectors of cables transmitting analog and digital signals, respectively, without necessarily including cables. 
     The playback device  110   a , for example, can receive media content (e.g., audio content comprising music and/or other sounds) from a local audio source  105  via the input/output  111  (e.g., a cable, a wire, a PAN, a Bluetooth connection, an ad hoc wired or wireless communication network, and/or another suitable communication link). The local audio source  105  can comprise, for example, a mobile device (e.g., a smartphone, a tablet, a laptop computer) or another suitable audio component (e.g., a television, a desktop computer, an amplifier, a phonograph, a Blu-ray player, a memory storing digital media files). In some examples, the local audio source  105  includes local music libraries on a smartphone, a computer, a networked-attached storage (NAS), and/or another suitable device configured to store media files. In certain examples, one or more of the playback devices  110 , NMDs  120 , and/or control devices  130  comprise the local audio source  105 . In other examples, however, the media playback system omits the local audio source  105  altogether. In some examples, the playback device  110   a  does not include an input/output  111  and receives all audio content via the network  104 . 
     The playback device  110   a  further comprises electronics  112 , a user interface  113  (e.g., one or more buttons, knobs, dials, touch-sensitive surfaces, displays, touchscreens), and one or more transducers  114  (referred to hereinafter as “the transducers  114 ”). The electronics  112  is configured to receive audio from an audio source (e.g., the local audio source  105 ) via the input/output  111 , one or more of the computing devices  106   a - c  via the network  104  ( FIG. 1B )), amplify the received audio, and output the amplified audio for playback via one or more of the transducers  114 . In some examples, the playback device  110   a  optionally includes one or more microphones  115  (e.g., a single microphone, a plurality of microphones, a microphone array) (hereinafter referred to as “the microphones  115 ”). In certain examples, for example, the playback device  110   a  having one or more of the optional microphones  115  can operate as an NMD configured to receive voice input from a user and correspondingly perform one or more operations based on the received voice input. 
     In the illustrated example of  FIG. 1C , the electronics  112  comprise one or more processors  112   a  (referred to hereinafter as “the processors  112   a ”), memory  112   b , software components  112   c , a network interface  112   d , one or more audio processing components  112   g  (referred to hereinafter as “the audio components  112   g ”), one or more audio amplifiers  112   h  (referred to hereinafter as “the amplifiers  112   h ”), and power  112   i  (e.g., one or more power supplies, power cables, power receptacles, batteries, induction coils, Power-over Ethernet (POE) interfaces, and/or other suitable sources of electric power). In some examples, the electronics  112  optionally include one or more other components  112   j  (e.g., one or more sensors, video displays, touchscreens, battery charging bases). 
     The processors  112   a  can comprise clock-driven computing component(s) configured to process data, and the memory  112   b  can comprise a computer-readable medium (e.g., a tangible, non-transitory computer-readable medium, data storage loaded with one or more of the software components  112   c ) configured to store instructions for performing various operations and/or functions. The processors  112   a  are configured to execute the instructions stored on the memory  112   b  to perform one or more of the operations. The operations can include, for example, causing the playback device  110   a  to retrieve audio data from an audio source (e.g., one or more of the computing devices  106   a - c  ( FIG. 1B )), and/or another one of the playback devices  110 . In some examples, the operations further include causing the playback device  110   a  to send audio data to another one of the playback devices  110   a  and/or another device (e.g., one of the NMDs  120 ). Certain examples include operations causing the playback device  110   a  to pair with another of the one or more playback devices  110  to enable a multi-channel audio environment (e.g., a stereo pair, a bonded zone). 
     The processors  112   a  can be further configured to perform operations causing the playback device  110   a  to synchronize playback of audio content with another of the one or more playback devices  110 . As those of ordinary skill in the art will appreciate, during synchronous playback of audio content on a plurality of playback devices, a listener will preferably be unable to perceive time-delay differences between playback of the audio content by the playback device  110   a  and the other one or more other playback devices  110 . Additional details regarding audio playback synchronization among playback devices can be found, for example, in U.S. Pat. No. 8,234,395, which was incorporated by reference above. 
     In some examples, the memory  112   b  is further configured to store data associated with the playback device  110   a , such as one or more zones and/or zone groups of which the playback device  110   a  is a member, audio sources accessible to the playback device  110   a , and/or a playback queue that the playback device  110   a  (and/or another of the one or more playback devices) can be associated with. The stored data can comprise one or more state variables that are periodically updated and used to describe a state of the playback device  110   a . The memory  112   b  can also include data associated with a state of one or more of the other devices (e.g., the playback devices  110 , NMDs  120 , control devices  130 ) of the media playback system  100 . In some examples, for instance, the state data is shared during predetermined intervals of time (e.g., every 5 seconds, every 10 seconds, every 60 seconds) among at least a portion of the devices of the media playback system  100 , so that one or more of the devices have the most recent data associated with the media playback system  100 . 
     The network interface  112   d  is configured to facilitate a transmission of data between the playback device  110   a  and one or more other devices on a data network such as, for example, the links  103  and/or the network  104  ( FIG. 1B ). The network interface  112   d  is configured to transmit and receive data corresponding to media content (e.g., audio content, video content, text, photographs) and other signals (e.g., non-transitory signals) comprising digital packet data including an Internet Protocol (IP)-based source address and/or an IP-based destination address. The network interface  112   d  can parse the digital packet data such that the electronics  112  properly receives and processes the data destined for the playback device  110   a.    
     In the illustrated example of  FIG. 1C , the network interface  112   d  comprises one or more wireless interfaces  112   e  (referred to hereinafter as “the wireless interface  112   e ”). The wireless interface  112   e  (e.g., a suitable interface comprising one or more antennae) can be configured to wirelessly communicate with one or more other devices (e.g., one or more of the other playback devices  110 , NMDs  120 , and/or control devices  130 ) that are communicatively coupled to the network  104  ( FIG. 1B ) in accordance with a suitable wireless communication protocol (e.g., WiFi, Bluetooth, LTE). In some examples, the network interface  112   d  optionally includes a wired interface  112   f  (e.g., an interface or receptacle configured to receive a network cable such as an Ethernet, a USB-A, USB-C, and/or Thunderbolt cable) configured to communicate over a wired connection with other devices in accordance with a suitable wired communication protocol. In certain examples, the network interface  112   d  includes the wired interface  112   f  and excludes the wireless interface  112   e . In some examples, the electronics  112  excludes the network interface  112   d  altogether and transmits and receives media content and/or other data via another communication path (e.g., the input/output  111 ). 
     The audio components  112   g  are configured to process and/or filter data comprising media content received by the electronics  112  (e.g., via the input/output  111  and/or the network interface  112   d ) to produce output audio signals. In some examples, the audio processing components  112   g  comprise, for example, one or more digital-to-analog converters (DAC), audio preprocessing components, audio enhancement components, a digital signal processors (DSPs), and/or other suitable audio processing components, modules, circuits, etc. In certain examples, one or more of the audio processing components  112   g  can comprise one or more subcomponents of the processors  112   a . In some examples, the electronics  112  omits the audio processing components  112   g . In some examples, for instance, the processors  112   a  execute instructions stored on the memory  112   b  to perform audio processing operations to produce the output audio signals. 
     The amplifiers  112   h  are configured to receive and amplify the audio output signals produced by the audio processing components  112   g  and/or the processors  112   a . The amplifiers  112   h  can comprise electronic devices and/or components configured to amplify audio signals to levels sufficient for driving one or more of the transducers  114 . In some examples, for instance, the amplifiers  112   h  include one or more switching or class-D power amplifiers. In other examples, however, the amplifiers include one or more other types of power amplifiers (e.g., linear gain power amplifiers, class-A amplifiers, class-B amplifiers, class-AB amplifiers, class-C amplifiers, class-D amplifiers, class-E amplifiers, class-F amplifiers, class-G and/or class H amplifiers, and/or another suitable type of power amplifier). In certain examples, the amplifiers  112   h  comprise a suitable combination of two or more of the foregoing types of power amplifiers. Moreover, in some examples, individual ones of the amplifiers  112   h  correspond to individual ones of the transducers  114 . In other examples, however, the electronics  112  includes a single one of the amplifiers  112   h  configured to output amplified audio signals to a plurality of the transducers  114 . In some other examples, the electronics  112  omits the amplifiers  112   h.    
     The transducers  114  (e.g., one or more speakers and/or speaker drivers) receive the amplified audio signals from the amplifier  112   h  and render or output the amplified audio signals as sound (e.g., audible sound waves having a frequency between about 20 Hertz (Hz) and 20 kilohertz (kHz)). In some examples, the transducers  114  can comprise a single transducer. In other examples, however, the transducers  114  comprise a plurality of audio transducers. In some examples, the transducers  114  comprise more than one type of transducer. For example, the transducers  114  can include one or more low frequency transducers (e.g., subwoofers, woofers), mid-range frequency transducers (e.g., mid-range transducers, mid-woofers), and one or more high frequency transducers (e.g., one or more tweeters). As used herein, “low frequency” can generally refer to audible frequencies below about 500 Hz, “mid-range frequency” can generally refer to audible frequencies between about 500 Hz and about 2 kHz, and “high frequency” can generally refer to audible frequencies above 2 kHz. In certain examples, however, one or more of the transducers  114  comprise transducers that do not adhere to the foregoing frequency ranges. For example, one of the transducers  114  may comprise a mid-woofer transducer configured to output sound at frequencies between about 200 Hz and about 5 kHz. 
     By way of illustration, SONOS, Inc. presently offers (or has offered) for sale certain playback devices including, for example, a “SONOS ONE,” “MOVE,” “PLAY:5,” “BEAM,” “PLAYBAR,” “PLAYBASE,” “PORT,” “BOOST,” “AMP,” and “SUB.” Other suitable playback devices may additionally or alternatively be used to implement the playback devices of example examples disclosed herein. Additionally, one of ordinary skilled in the art will appreciate that a playback device is not limited to the examples described herein or to SONOS product offerings. In some examples, for example, one or more playback devices  110  comprises wired or wireless headphones (e.g., over-the-ear headphones, on-ear headphones, in-ear earphones). In other examples, one or more of the playback devices  110  comprise a docking station and/or an interface configured to interact with a docking station for personal mobile media playback devices. In certain examples, a playback device may be integral to another device or component such as a television, a lighting fixture, or some other device for indoor or outdoor use. In some examples, a playback device omits a user interface and/or one or more transducers. For example,  FIG. 1D  is a block diagram of a playback device  110   p  comprising the input/output  111  and electronics  112  without the user interface  113  or transducers  114 . 
       FIG. 1E  is a block diagram of a bonded playback device  110   q  comprising the playback device  110   a  ( FIG. 1C ) sonically bonded with the playback device  110   i  (e.g., a subwoofer) ( FIG. 1A ). In the illustrated example, the playback devices  110   a  and  110   i  are separate ones of the playback devices  110  housed in separate enclosures. In some examples, however, the bonded playback device  110   q  comprises a single enclosure housing both the playback devices  110   a  and  110   i . The bonded playback device  110   q  can be configured to process and reproduce sound differently than an unbonded playback device (e.g., the playback device  110   a  of  FIG. 1C ) and/or paired or bonded playback devices (e.g., the playback devices  110   l  and  110   m  of  FIG. 1B ). In some examples, for instance, the playback device  110   a  is full-range playback device configured to render low frequency, mid-range frequency, and high frequency audio content, and the playback device  110   i  is a subwoofer configured to render low frequency audio content. In some examples, the playback device  110   a , when bonded with the first playback device, is configured to render only the mid-range and high frequency components of a particular audio content, while the playback device  110   i  renders the low frequency component of the particular audio content. In some examples, the bonded playback device  110   q  includes additional playback devices and/or another bonded playback device. Additional playback device examples are described in further detail below with respect to  FIGS. 2A-2C . 
     c. Suitable Network Microphone Devices (NMDs) 
       FIG. 1F  is a block diagram of the NMD  120   a  ( FIGS. 1A and 1B ). The NMD  120   a  includes one or more voice processing components  124  (hereinafter “the voice components  124 ”) and several components described with respect to the playback device  110   a  ( FIG. 1C ) including the processors  112   a , the memory  112   b , and the microphones  115 . The NMD  120   a  optionally comprises other components also included in the playback device  110   a  ( FIG. 1C ), such as the user interface  113  and/or the transducers  114 . In some examples, the NMD  120   a  is configured as a media playback device (e.g., one or more of the playback devices  110 ), and further includes, for example, one or more of the audio components  112   g  ( FIG. 1C ), the amplifiers  114 , and/or other playback device components. In certain examples, the NMD  120   a  comprises an Internet of Things (IoT) device such as, for example, a thermostat, alarm panel, fire and/or smoke detector, etc. In some examples, the NMD  120   a  comprises the microphones  115 , the voice processing components  124 , and only a portion of the components of the electronics  112  described above with respect to  FIG. 1B . In some examples, for instance, the NMD  120   a  includes the processor  112   a  and the memory  112   b  ( FIG. 1B ), while omitting one or more other components of the electronics  112 . In some examples, the NMD  120   a  includes additional components (e.g., one or more sensors, cameras, thermometers, barometers, hygrometers). 
     In some examples, an NMD can be integrated into a playback device.  FIG. 1G  is a block diagram of a playback device  110   r  comprising an NMD  120   d . The playback device  110   r  can comprise many or all of the components of the playback device  110   a  and further include the microphones  115  and voice processing components  124  ( FIG. 1F ). The playback device  110   r  optionally includes an integrated control device  130   c . The control device  130   c  can comprise, for example, a user interface (e.g., the user interface  113  of  FIG. 1B ) configured to receive user input (e.g., touch input, voice input) without a separate control device. In other examples, however, the playback device  110   r  receives commands from another control device (e.g., the control device  130   a  of  FIG. 1B ). 
     Referring again to  FIG. 1F , the microphones  115  are configured to acquire, capture, and/or receive sound from an environment (e.g., the environment  101  of  FIG. 1A ) and/or a room in which the NMD  120   a  is positioned. The received sound can include, for example, vocal utterances, audio played back by the NMD  120   a  and/or another playback device, background voices, ambient sounds, etc. The microphones  115  convert the received sound into electrical signals to produce microphone data. The voice processing components  124  receive and analyzes the microphone data to determine whether a voice input is present in the microphone data. The voice input can comprise, for example, an activation word followed by an utterance including a user request. As those of ordinary skill in the art will appreciate, an activation word is a word or other audio cue that signifying a user voice input. For instance, in querying the AMAZON® VAS, a user might speak the activation word “Alexa.” Other examples include “Ok, Google” for invoking the GOOGLE® VAS and “Hey, Siri” for invoking the APPLE® VAS. 
     After detecting the activation word, voice processing components  124  monitor the microphone data for an accompanying user request in the voice input. The user request may include, for example, a command to control a third-party device, such as a thermostat (e.g., NEST® thermostat), an illumination device (e.g., a PHILIPS HUE® lighting device), or a media playback device (e.g., a Sonos® playback device). For example, a user might speak the activation word “Alexa” followed by the utterance “set the thermostat to 68 degrees” to set a temperature in a home (e.g., the environment  101  of  FIG. 1A ). The user might speak the same activation word followed by the utterance “turn on the living room” to turn on illumination devices in a living room area of the home. The user may similarly speak an activation word followed by a request to play a particular song, an album, or a playlist of music on a playback device in the home. 
     d. Suitable Control Devices 
       FIG. 1H  is a partially schematic diagram of the control device  130   a  ( FIGS. 1A and 1B ). As used herein, the term “control device” can be used interchangeably with “controller” or “control system.” Among other features, the control device  130   a  is configured to receive user input related to the media playback system  100  and, in response, cause one or more devices in the media playback system  100  to perform an action(s) or operation(s) corresponding to the user input. In the illustrated example, the control device  130   a  comprises a smartphone (e.g., an iPhone™, an Android phone) on which media playback system controller application software is installed. In some examples, the control device  130   a  comprises, for example, a tablet (e.g., an iPad™), a computer (e.g., a laptop computer, a desktop computer), and/or another suitable device (e.g., a television, an automobile audio head unit, an IoT device). In certain examples, the control device  130   a  comprises a dedicated controller for the media playback system  100 . In other examples, as described above with respect to  FIG. 1G , the control device  130   a  is integrated into another device in the media playback system  100  (e.g., one more of the playback devices  110 , NMDs  120 , and/or other suitable devices configured to communicate over a network). 
     The control device  130   a  includes electronics  132 , a user interface  133 , one or more speakers  134 , and one or more microphones  135 . The electronics  132  comprise one or more processors  132   a  (referred to hereinafter as “the processors  132   a ”), a memory  132   b , software components  132   c , and a network interface  132   d . The processor  132   a  can be configured to perform functions relevant to facilitating user access, control, and configuration of the media playback system  100 . The memory  132   b  can comprise data storage that can be loaded with one or more of the software components executable by the processor  132   a  to perform those functions. The software components  132   c  can comprise applications and/or other executable software configured to facilitate control of the media playback system  100 . The memory  112   b  can be configured to store, for example, the software components  132   c , media playback system controller application software, and/or other data associated with the media playback system  100  and the user. 
     The network interface  132   d  is configured to facilitate network communications between the control device  130   a  and one or more other devices in the media playback system  100 , and/or one or more remote devices. In some examples, the network interface  132   d  is configured to operate according to one or more suitable communication industry standards (e.g., infrared, radio, wired standards including IEEE 802.3, wireless standards including IEEE 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.15, 4G, LTE). The network interface  132   d  can be configured, for example, to transmit data to and/or receive data from the playback devices  110 , the NMDs  120 , other ones of the control devices  130 , one of the computing devices  106  of  FIG. 1B , devices comprising one or more other media playback systems, etc. The transmitted and/or received data can include, for example, playback device control commands, state variables, playback zone and/or zone group configurations. For instance, based on user input received at the user interface  133 , the network interface  132   d  can transmit a playback device control command (e.g., volume control, audio playback control, audio content selection) from the control device  130  to one or more of the playback devices  110 . The network interface  132   d  can also transmit and/or receive configuration changes such as, for example, adding/removing one or more playback devices  110  to/from a zone, adding/removing one or more zones to/from a zone group, forming a bonded or consolidated player, separating one or more playback devices from a bonded or consolidated player, among others. 
     The user interface  133  is configured to receive user input and can facilitate ‘control of the media playback system  100 . The user interface  133  includes media content art 133a (e.g., album art, lyrics, videos), a playback status indicator  133   b  (e.g., an elapsed and/or remaining time indicator), media content information region  133   c , a playback control region  133   d , and a zone indicator  133   e . The media content information region  133   c  can include a display of relevant information (e.g., title, artist, album, genre, release year) about media content currently playing and/or media content in a queue or playlist. The playback control region  133   d  can include selectable (e.g., via touch input and/or via a cursor or another suitable selector) icons to cause one or more playback devices in a selected playback zone or zone group to perform playback actions such as, for example, play or pause, fast forward, rewind, skip to next, skip to previous, enter/exit shuffle mode, enter/exit repeat mode, enter/exit cross fade mode, etc. The playback control region  133   d  may also include selectable icons to modify equalization settings, playback volume, and/or other suitable playback actions. In the illustrated example, the user interface  133  comprises a display presented on a touch screen interface of a smartphone (e.g., an iPhone™, an Android phone). In some examples, however, user interfaces of varying formats, styles, and interactive sequences may alternatively be implemented on one or more network devices to provide comparable control access to a media playback system. 
     The one or more speakers  134  (e.g., one or more transducers) can be configured to output sound to the user of the control device  130   a . In some examples, the one or more speakers comprise individual transducers configured to correspondingly output low frequencies, mid-range frequencies, and/or high frequencies. In some examples, for instance, the control device  130   a  is configured as a playback device (e.g., one of the playback devices  110 ). Similarly, in some examples the control device  130   a  is configured as an NMD (e.g., one of the NMDs  120 ), receiving voice commands and other sounds via the one or more microphones  135 . 
     The one or more microphones  135  can comprise, for example, one or more condenser microphones, electret condenser microphones, dynamic microphones, and/or other suitable types of microphones or transducers. In some examples, two or more of the microphones  135  are arranged to capture location information of an audio source (e.g., voice, audible sound) and/or configured to facilitate filtering of background noise. Moreover, in certain examples, the control device  130   a  is configured to operate as playback device and an NMD. In other examples, however, the control device  130   a  omits the one or more speakers  134  and/or the one or more microphones  135 . For instance, the control device  130   a  may comprise a device (e.g., a thermostat, an IoT device, a network device) comprising a portion of the electronics  132  and the user interface  133  (e.g., a touch screen) without any speakers or microphones. 
     III. Example Systems and Devices 
       FIG. 2A  is a front isometric view of a playback device  210  configured in accordance with examples of the disclosed technology.  FIG. 2B  is a front isometric view of the playback device  210  without a grille  216   e .  FIG. 2C  is an exploded view of the playback device  210 . Referring to  FIGS. 2A-2C  together, the playback device  210  comprises a housing  216  that includes an upper portion  216   a , a right or first side portion  216   b , a lower portion  216   c , a left or second side portion  216   d , the grille  216   e , and a rear portion  216   f . A plurality of fasteners  216   g  (e.g., one or more screws, rivets, clips) attaches a frame  216   h  to the housing  216 . A cavity  216   j  ( FIG. 2C ) in the housing  216  is configured to receive the frame  216   h  and electronics  212 . The frame  216   h  is configured to carry a plurality of transducers  214  (identified individually in  FIG. 2B  as transducers  214   a - f ). The electronics  212  (e.g., the electronics  112  of  FIG. 1C ) is configured to receive audio content from an audio source and send electrical signals corresponding to the audio content to the transducers  214  for playback. 
     The transducers  214  are configured to receive the electrical signals from the electronics  112 , and further configured to convert the received electrical signals into audible sound during playback. For instance, the transducers  214   a - c  (e.g., tweeters) can be configured to output high frequency sound (e.g., sound waves having a frequency greater than about 2 kHz). The transducers  214   d - f  (e.g., mid-woofers, woofers, midrange speakers) can be configured output sound at frequencies lower than the transducers  214   a - c  (e.g., sound waves having a frequency lower than about 2 kHz). In some examples, the playback device  210  includes a number of transducers different than those illustrated in  FIGS. 2A-2C . For example, the playback device  210  can include fewer than six transducers (e.g., one, two, three). In other examples, however, the playback device  210  includes more than six transducers (e.g., nine, ten). Moreover, in some examples, all or a portion of the transducers  214  are configured to operate as a phased array to desirably adjust (e.g., narrow or widen) a radiation pattern of the transducers  214 , thereby altering a user&#39;s perception of the sound emitted from the playback device  210 . 
     In the illustrated example of  FIGS. 2A-2C , a filter  216   i  is axially aligned with the transducer  214   b . The filter  216   i  can be configured to desirably attenuate a predetermined range of frequencies that the transducer  214   b  outputs to improve sound quality and a perceived sound stage output collectively by the transducers  214 . In some examples, however, the playback device  210  omits the filter  216   i . In other examples, the playback device  210  includes one or more additional filters aligned with the transducers  214   b  and/or at least another of the transducers  214 . 
       FIG. 3A  is a perspective view of a playback device  310 ,  FIG. 3B  shows the playback device  310  in an exploded view with some components hidden for clarity, and  FIG. 3C  shows a top view of the playback device  310  with some components hidden for clarity. The playback device  310  includes a body defined by housing  316 , which is elongated along a longitudinal axis. The housing  316  defines an interior volume therein, and includes an upper portion  316   a , a first side or left portion  316   b , an opposing second side or right portion  316   c , and a forward portion  316   d , and a lower portion  316   e . In some examples, the housing  316  can define a curved surface, for instance, with a curved transition between the upper portion  316   a  and the forward portion  316   d , and/or with a curved transition between the forward portion  316   d  and the lower portion  316   e . Such curved profiles can be particularly desirable from a design perspective, as the human eye tends to perceive objects with curved profiles as occupying a smaller volume. As such, a soundbar or other such playback device can appear smaller and more discreet by employing curved transitions along the outer surface. 
     As shown in  FIG. 3B , a frame  320  can be positioned within the housing  316 . The frame  320  can define a plurality of openings configured to receive one or more transducers  314   a - d  (collectively “transducers  314 ”) therein. For example, the frame  320  can couple to transducers  314   a ,  314   b ,  314   c  and  314   d . The transducers  314  coupled to the frame  320  and disposed within the housing  316  can be similar or identical to any one of the transducers  214   a - f  described previously. 
     The playback device  310  can include one or more acoustic ports  350   a  and  350   b  (collectively “acoustic ports  350 ”). In various examples, a port can take the form of a conduit, duct, tube, or any other suitable structure. In some examples, the acoustic ports  350  can be a bass reflex port. The acoustic ports  350  can allow for air to flow through from outside of the playback device  310  to the internal volume of the playback device  310 . The acoustic ports  350  can be tuned to have a specific resonant frequency. For example, the internal volume of the playback device  310 , the effective length of the acoustic ports  350 , and the cross-sectional area of the acoustic ports  350  can be adjusted so that the air within the acoustic ports  350  resonates at a particular frequency or a particular range of frequencies. In various examples, the acoustic port  350  can have a curved profile so that at least part of the flow path is non-linear. For example, the acoustic ports  350  can have a “U” or “J” shape. The frame  320  can define a plurality of openings to receive the acoustic ports  350 . For example, the acoustic port  350   a  can couple to the first aperture  322   a  near the right end  321   a  of the frame  320 , and the acoustic port  350   b  can couple to the second aperture  322   b  near the left end  321   b  of frame  320 . 
     In some examples, the playback device  310  takes the form of a soundbar that is elongated along the length of the playback device  310  and is configured to face a primary sound axis that is substantially orthogonal to the length of the playback device  310 . In various examples, the playback device  310  has other forms, for instance, having more or fewer transducers, having other form-factors, having more or fewer acoustic ports, and/or having any other suitable modifications with respect to the example shown in  FIGS. 3A-C . 
       FIG. 4A  is perspective view of an acoustic port  450 ,  FIG. 4B  is a perspective sectional view of the acoustic port  450 , and  4 C is a top sectional view of the acoustic port  450 . The acoustic port  450  can include a wall  410  that defines the body of the acoustic port  450 . A first aperture  412  can be positioned at one end of the wall  410  and a second aperture  414  can be positioned at the second end of the wall  410 . The wall  410 , first aperture  412 , and second aperture  414  can form a passageway  416  within the acoustic port  450  through which air (or another suitable fluid) can flow. In some examples, air flows through the passageway  416  from the first aperture  412  toward the second aperture  414 . Within the passageway  416 , the port  450  can include a first vane  418   a , a second vane  418   b , and a third vane  418   c . The first vane  418   a , second vane  418   b , and third vane  418   c  (collectively “the vanes  418 ”) can couple to the wall  410  and extend into the passageway  416  (e.g., extending from an interior surface of the wall  410  and into a radially central region of the passageway  416 ). In some examples, the passageway  416  can take the form of a chamber, lumen, flow path, or other suitable structure through which air can flow. The vanes  418  can divide part or all of the passageway  416  into two or more channels  421 . For example, as illustrated in  FIGS. 4A-4C , the first vane  418   a , second vane  418   b , and third vanes  418   c  divide part of the passageway  416  into four channels  421   a ,  421   b ,  421   c , and  421   d . In some examples, air flowing within the passageway  416  can be divided by the vanes  418  and flow through one or more of the channels  421   a - d . In some examples, the channels  421  can each take the form of a chamber, lumen, flow path, or other suitable structure through which air can flow. 
     The wall  410  can be curved along an axial direction so that the body of the acoustic port  450  has a curved profile. The curved wall  410  can result in the passageway  416  having a curved section or sections along at least a portion of the passageway  416 . For example, as illustrated in  FIG. 4C , the axis A 1  extending through the center of the passageway  416  is not straight along at least a portion of the length of the passageway. In various examples, the wall  410  curves in the axial direction about a center of curvature Cl. In some examples, substantially all of the wall  410  is curved so that entire body of the acoustic port  450  has a curved profile. In various examples, some sections of the wall  410  are not curved. For example, the wall  410  can have a section of the wall  410  that is substantially straight along the axial direction while a separate section of the wall  410  is at least partially curved along the axial direction. In some examples, the wall  410  is not curved and has a substantially straight profile. In various examples, the wall  410  curves by greater than 90 degrees along the axial direction. For example, the wall  410  can have a curve about (e.g. plus or minus 10%, 5%, 1%, or less than 1%) 135 degrees, 180 degrees, 225 degrees, 270 degrees, or 315 degrees. In some examples, the wall  410  can curve beyond 360 degrees and form a spiral. The curvature of the wall  410  can orient the first aperture  412  and second aperture  414  in a non-parallel manner. For example, as illustrated in  FIGS. 4A-4C , the first aperture  412  is oriented along a first plane and the second aperture  414  is oriented along a second plane that would intersect the first plane. 
     The vanes  418  can each have a first end  419  and a second end  420  with a body extending between the first end  419  and second end  420 . In some examples, the vanes  418  do not have a uniform thickness. For example, as illustrated in  FIGS. 4A-4C , the vanes  418  can be tapered near the first end  419  and second end  420  so that the vanes  418  have a smaller thickness at the first end  419  and second end  420  than in the central body portion. Tapering the first ends  419  and second ends  420  of the vanes  418  can reduce the drag the vanes  418  exert on air flowing through the passageway  416  and can decrease the turbulence generated at the interface of inflowing or outflowing air at the ends  419  and  420  of the vanes  418 . The vanes  418  can extend along a portion of the axial length of the acoustic port  450 . For example, as illustrated in  FIGS. 4A-4C , the vanes  418  are spaced apart from the first aperture  412  and second aperture  414  so that the first ends  419   a - c  of the vanes  418  are located proximate the first aperture  412  and that the second ends  420   a - c  are located proximate the second aperture  414 . Accordingly, the axial length of the vanes  418  can be shorter than the axial length of the acoustic port  450 . In various examples, the vanes  418  can extend along the entire length of the acoustic port  450 . In some examples, the length of the vanes  418  can be shorter than the length of the passageway  416 . In various examples, the vanes  418  can have different lengths. For example, the first vane  418   a  can be longer than the second vane  418   b , which can be longer than the third vane  418   c . In some examples, the first ends  419 , second ends  420 , or both the first ends  419  and second ends  420  of the vanes  418  can be spaced apart from each other along the axial direction. For example, as illustrated in  FIGS. 4A-4C , the first end  419   c  is axially spaced apart from the first end  419   b , which is axially spaced apart from the first end  419   a . In some examples, some vanes  418  can be positioned closer to the first aperture  412 , second aperture  414 , or both the first aperture  412  and second aperture  414  than the other vanes  418 . 
     In various examples, the acoustic port  450  can have one or more vanes  418 . For example, as illustrated in  FIGS. 4A-4C , the acoustic port  450  can have three vanes  418 . In some examples, the acoustic port  450  can have a different number of vanes  418 . For example, the acoustic port  450  can have one, two, four, five, six, seven, eight, nine, ten, or more vanes  418 . The vanes  418  can be spaced apart from one another along a radial direction (e.g. a direction that is perpendicular to the flow of air, a direction that is perpendicular or orthogonal to the axial direction, and/or a direction that is extending outwards from a center of curvature). For example, as illustrated in  FIG. 4C , the first vane  418   a  can be disposed nearer to the center of curvature Cl than the second vane  418   b  and third vane  418   c . In some examples, the vanes  418  are spaced apart from one another along the radial direction by substantially the same distance. In various examples, the vanes  418  are spaced apart from one another along the radial direction by different distances. In some examples, the lengths and widths of the channels  421  (as defined by the vanes  418 ) can be configured such that the cross-sectional area and/or total volume of each of the channels  421  are substantially the same. In other examples, the cross-sectional area and/or total volume of two or more of the channels  421  can vary from one another. 
     In some examples, the vanes  418  can be substantially parallel to one another along the axial direction. Additionally or alternatively, some or all of the vanes  418  can extend along the passageway  416  along a direction substantially parallel to the wall  410  of the port  450 . As such, the channels  421  defined by the vanes  418  can have widths or cross-sectional areas that are substantially constant along at least a portion of the lengths of the vanes  418 . In various examples, the vanes  418  are not substantially parallel to one another along the axial direction. 
     As noted previously, the channels  421  can be formed within the passageway  416 . The channels  421  can be defined by the space between the walls  410  and the vanes  418 . For example, as illustrated in  FIGS. 4A-4C , the first channel  421   a  can be defined by the space between the wall  410  and the first vane  418   a , and the second channel  421   b  can be defined by the space between the wall  410 , the first vane  418   a , and the second vane  418   b . In some examples, the channels  421  can have an axial length that is defined by the shortest vane  418  forming the channel  421 . For example, in reference to  FIG. 4C , the first channel  421   a  can have an axial length that is equal to the length of the first vane  418   a , the second channel  421   b  can have an axial length that is equal to the length of the second vane  418   b , and the third channel  421   c  and fourth channel  421   d  can have an axial length that is equal to the length of the third vane  418   c . In some examples, the channels  421  can have different lengths. For example, as illustrated in  FIGS. 4A-4C , the first channel  421   a  can be longer than the second channel  421   b , which is longer than the third channel  421   c  and fourth channel  421   d . In some examples, the channels  421  have substantially the same length. In various examples, the channels  421  can have substantially the same cross-sectional area. For example, the vanes  418  can be evenly spaced along the radial direction so cross-sectional areas of the channels  421  are substantially the same. In some examples, the cross-sectional areas of the channels  421  can be different. 
     In various examples, the acoustic port  450  can have any suitable number of channels  421 . For example, the acoustic port  450  can have two, three, five, six, seven, eight, nine, ten, eleven, or more channels. In some examples, the acoustic port  450  comprises no channels within the passageway  416 . 
     In some examples, the passageway  416  does not have a uniform thickness. For example, as illustrated in  FIGS. 4A-4C , the passageway  416  can be wider along the radial direction at the first aperture  412  and second aperture  414  than at the sections between the first aperture  412  and second aperture  414 . In various examples, the passageway  416  has a uniform thickness along the axial length of the vanes  418 . In some examples, the passageway  416  continuously narrows from the first aperture  412  to the first end  419  of the vane so that the width of the passageway  416  at the first end  419  of the vane  418  is narrower than the width of the passageway  416  at the first aperture  412 . 
     During operation of the playback device, the vanes  418  can reduce turbulence of airflow within the passageway  416 . The vanes can separate the airflow within the passageway  416  so the airflow is divided and flows into the separate channels  421 . Because the individual channels  421  each have a smaller cross-sectional area than the entirety of the passageway  416 , the airflow within the individual channels  421  exhibits flow characteristics that are more uniform and laminar compared to airflow within a passageway  416  without any vanes  418 . With more uniform and laminar airflow, unwanted noise within the acoustic port  450  can be reduced, minimized, or eliminated. Accordingly, the vanes  418  can reduce noise caused by the turbulence associated with air flow through a curved acoustic port  450 . 
       FIG. 5  is a perspective view of an acoustic port  550 . In some examples, the acoustic port  550  can be similar to the acoustic port  450  and the acoustic port  350  by having similar components and functioning in a similar manner. The acoustic port  550  can include an upper portion  526  and a lower portion  528 . The upper portion  526  can couple with the lower portion  528  to form a passageway  516  similar to the passageway  416 . One or more upper vanes  530  can be coupled to the upper portion  526 . The upper vanes  530  can extend from the upper portion  526  and into the passageway  516 . One or more vanes  532  can be coupled to the lower portion  528 . The lower vanes  532  can extend from the lower portion  528  and into the passageway  516 . In some examples, the upper vanes  530  and lower vanes  532  can be spaced apart radially from the upper portion  526  and lower portion  528  so that the upper vanes  530  and lower vanes  532  align. In various examples, the upper vanes  530  and lower vanes  532  can function as single vane (e.g. the upper vane  530  and lower vane  532  can define one or channels). In some examples, the upper vane  530  and lower vane  532  have a gap  502  formed between the upper vane  530  and lower vane  532 . In various example, the presence of a gap  502  between the upper vane  530  and lower vane  532  does not impact the overall effectiveness of reducing unwanted noise within the acoustic port  550  due to the curvature of the acoustic port  550 . 
     In some instances, the vertical gap  502  between the upper vane  530  and the lower vane  532  can facilitate manufacturing and assembly of the completed port  550 . For example, a lower portion (including the lower vane  532 ) can be separately formed (e.g., using injection molding, casting, or other suitable technique) and mated with a separately formed upper portion (including the upper vane  502 ). By including a vertical gap  502 , the upper and lower portions can be mated together even if small defects or manufacturing irregularities are present along the mating surfaces of the upper and lower portions. 
       FIG. 6  is a perspective view of an acoustic port  650  coupled to the frame  320  of the playback device. In some examples, the acoustic port  650  can be similar to the acoustic port  550 , the acoustic port  450 , and the acoustic port  350  by having similar components and functioning in a similar manner. The frame  320  can have an acoustic wall  623 . The acoustic wall  623  can be positioned on the frame  320  so that the acoustic wall  623  aligns with the acoustic port  650  when the acoustic port  650  couples to the frame  320 . The acoustic wall  623  can function as an extension of the acoustic port  650 . For example, the acoustic wall  623  can form part of the passageway  616 , with the passageway  616  being similar to the passageway  516  and passageway  416 . In some examples, a vane  618  can couple to the acoustic wall  623  and extend into the passageway  616 . In various examples, the vane  618  can couple to both the acoustic wall  623  and the wall  610  of the acoustic port  650 . By forming an acoustic wall  623  within the frame  320 , the acoustic port  650  can be designed in a more compact manner, as the acoustic wall  623  can account for part of the effective length of the overall acoustic port  650 . 
     III. Conclusion 
     The above discussions relating to playback devices, controller devices, playback zone configurations, and media content sources provide only some examples of operating environments within which functions and methods described below may be implemented. Other operating environments and/or configurations of media playback systems, playback devices, and network devices not explicitly described herein may also be applicable and suitable for implementation of the functions and methods. 
     The description above discloses, among other things, various example systems, methods, apparatus, and articles of manufacture including, among other components, firmware and/or software executed on hardware. It is understood that such examples are merely illustrative and should not be considered as limiting. For example, it is contemplated that any or all of the firmware, hardware, and/or software examples or components can be embodied exclusively in hardware, exclusively in software, exclusively in firmware, or in any combination of hardware, software, and/or firmware. Accordingly, the examples provided are not the only ways) to implement such systems, methods, apparatus, and/or articles of manufacture. 
     Additionally, references herein to “example” means that a particular feature, structure, or characteristic described in connection with the example can be included in at least one example of an invention. The appearances of this phrase in various places in the specification are not necessarily all referring to the same example, nor are separate or alternative examples mutually exclusive of other examples. As such, the examples described herein, explicitly and implicitly understood by one skilled in the art, can be combined with other examples. 
     The specification is presented largely in terms of illustrative environments, systems, procedures, steps, logic blocks, processing, and other symbolic representations that directly or indirectly resemble the operations of data processing devices coupled to networks. These process descriptions and representations are typically used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art. Numerous specific details are set forth to provide a thorough understanding of the present disclosure. However, it is understood to those skilled in the art that certain examples of the present disclosure can be practiced without certain, specific details. In other instances, well known methods, procedures, components, and circuitry have not been described in detail to avoid unnecessarily obscuring examples of the examples. Accordingly, the scope of the present disclosure is defined by the appended claims rather than the foregoing description of examples. 
     When any of the appended claims are read to cover a purely software and/or firmware implementation, at least one of the elements in at least one example is hereby expressly defined to include a tangible, non-transitory medium such as a memory, DVD, CD, Blu-ray, and so on, storing the software and/or firmware. 
     The disclosed technology is illustrated, for example, according to various examples described below. Various examples of examples of the disclosed technology are described as numbered examples (1, 2, 3, etc.) for convenience. These are provided as examples and do not limit the disclosed technology. It is noted that any of the dependent examples may be combined in any combination, and placed into a respective independent example. The other examples can be presented in a similar manner. 
     Example 1. A playback device comprising: a housing defining an acoustic volume therein; one or more audio transducers disposed at least partially within the housing; and an acoustic port extending through the housing, the acoustic port comprising: a wall defining a first aperture, a second aperture, and a passageway extending therebetween, the wall being at least partially curved along an axial direction; and a plurality of vanes coupled to the wall and extending into the passageway such that the vanes define a plurality of channels extending axially within the passageway. 
     Example 2. The playback device of claim  1 , wherein the plurality of vanes extend substantially parallel to one another along the axial direction. 
     Example 3. The playback device of any one of the proceeding Examples, wherein the plurality of channels have substantially identical cross-sectional areas taken along a radial direction orthogonal to the axial direction. 
     Example 4. The playback device of any of the preceding Examples, wherein the plurality of channels have substantially equal lengths along the axial direction. 
     Example 5. The playback device of any of the preceding Examples, wherein the plurality of vanes have different lengths along the axial direction. 
     Example 6. The playback device of any of the preceding Examples, wherein the plurality of vanes extend axially along only a portion of a length of the passageway. 
     Example 7. The playback device of any of the preceding Examples, wherein each of the plurality of vanes extends between a first end proximate the first aperture and a second end proximate the second aperture, and wherein the first ends of the plurality of vanes are offset from one another in the axial direction. 
     Example 8. The playback device of Example 7, wherein the wall curves in the axial direction about a center of curvature, wherein the plurality of vanes includes a first vane and a second vane having corresponding first ends, and wherein the first vane is disposed nearer to the center of curvature than is the second vane, and wherein the first end of the first vane is positioned nearer to the first aperture than the first end of the second vane. 
     Example 9. The playback device of any of the preceding Examples, wherein each of the plurality of vanes extends between a first end proximate the first aperture and a second end proximate the second aperture, and wherein the second ends of the plurality of vanes are offset from one another in the axial direction. 
     Example 10. The playback device of Example 9, wherein the wall curves in the axial direction about a center of curvature, wherein the plurality of vanes includes a first vane and a second vane having corresponding first ends and second ends, and wherein the first vane is disposed nearer to the center of curvature than is the second vane, and wherein the second end of the first vane is positioned nearer to the second aperture than the second end of the second vane. 
     Example 11. The playback device of any of the preceding Examples, wherein each of the plurality of vanes extends between a first end portion proximate the first aperture and a second end portion proximate the second aperture, and wherein a thickness of each of the vanes tapers from a first thickness at the first and second end portions to a second thickness. 
     Example 12. The playback device of any of the preceding Examples, wherein the wall curves along the axial direction by greater than 90 degrees. 
     Example 13. The playback device of any of the preceding Examples, wherein the first aperture is oriented along a first plane and the second aperture is oriented along a second plane that intersects the first plane. 
     Example 14. The playback device of any of the preceding Examples, wherein an axial axis extending through a center of the passageway is not straight along at least a portion of the length of the passageway. 
     Example 15. A playback device comprising: a housing defining an interior volume therein; an audio transducer disposed at least partially within the housing; and a tube extending through the housing, the tube comprising: a wall defining a first aperture, a second aperture, and a passageway extending axially between the first aperture and the second aperture, the wall being at least partially curved or bent along the axial direction; and a vane coupled to the wall and extending into the passageway such that the vane defines a first channel and a second channel within the passageway. 
     Example 16. The playback device of Example 15, wherein the vane is a first vane, the tube further comprising a second vane coupled to the wall and extending into the passageway, the second vane being spaced apart from the first vane such that the second vane defines a third channel within the passageway. 
     Example 17. The playback device of Example 16, wherein the first vane is longer in the axial direction than the second vane. 
     Example 18. The playback device of Examples 16 or 17, wherein the first vane and second vane extend substantially parallel to one another along the axial direction. 
     Example 19. The playback device of any of the Examples 16-18, wherein the first channel, second channel, and third channel have substantially identical cross-sectional areas taken along a direction orthogonal to the axial direction. 
     Example 20. The playback device of any of the Examples 16-19, wherein the first channel, second channel, and third channel have substantially equal lengths along the axial direction. 
     Example 21. The playback device of any of the Examples 16-20, wherein the first vane and second vane have different lengths along the axial direction. 
     Example 22. The playback device of any of the Examples 16-21, wherein the first vane and second vane extend axially along only a portion of a length of the passageway. 
     Example 23. The playback device of any of the Examples 16-22, wherein each of the first vane and second vane extend between a first end proximate the first aperture and a second end proximate the second aperture, and wherein the first ends of the first and second vanes are offset from one another in the axial direction. 
     Example 24. The playback device of Example 23, wherein the wall curves in the axial direction about a center of curvature, and wherein a first vane disposed nearer to the center of curvature has a first end positioned nearer the first aperture than a second vane disposed further from the center of curvature. 
     Example 25. The playback device of any of the Examples 16-24, wherein each of the first vane and second vane extend between a first end proximate the first aperture and a second end proximate the second aperture, and wherein the second ends of the first and second vanes are offset from one another in the axial direction. 
     Example 26. The playback device of Example 25, wherein the wall curves in the axial direction about a center of curvature, and wherein a first vane disposed nearer to the center of curvature has a second end positioned nearer the interior aperture than a second vane disposed further from the center of curvature. 
     Example 27. The playback device of any of the Examples 16-26, wherein each of the first vane and second vane extend between a first end portion proximate the first aperture and a second end portion proximate the second aperture, and wherein a thickness of each of the vanes tapers at the first and second end portions. 
     Example 28. The playback device of any of the Examples 15-27, wherein the wall curves along the axial direction by greater than 90 degrees. 
     Example 29. The playback device of any of the Examples 15-28, wherein the first aperture is oriented along a first plane and the second aperture is oriented along a second plane that intersects the first plane. 
     Example 30. The playback device of any of the Examples 15-29, wherein a axial axis extending through a center of the passageway is not straight along at least a portion of the length of the passageway. 
     Example 31. The playback device of any of the Examples 15-30, wherein the vane comprises a first portion, a second portion, and a gap between the first and second portion. 
     Example 32. A port comprising: an outer wall defining a chamber, a first opening at a first end, a second opening at a second end, and a length extending axially between the first and second end, the outer wall having a curve or bend in the axial direction along at least a portion of the length; and a vane extending from the outer wall the chamber that at least partially divides the chamber into a first chamber portion and a second chamber portion, the vane having a first end, a second end, and an intermediate portion therebetween. 
     Example 33. The port of Example 32, wherein the vane is a first vane, the port further comprising a second vane coupled to the outer wall and extending into the chamber, the second vane being spaced apart from the first vane, the second vane having a first end, a second end, and an intermediate portion therebetween, wherein the length of the second vane is smaller than the length of the chamber. 
     Example 34. The port of Example 33, wherein the first end of the first vane is closer to the first end of the chamber than the first end and second end of the second vane. 
     Example 35. The port of Examples 33 or 34, wherein the length of the first vane is longer than the length of the second vane. 
     Example 36. The port of any of the Examples 33-35, wherein the first vane and second vane are about parallel. 
     Example 37. The port of any of the Examples 32-36, wherein the first end and second end of the vane are tapered. 
     Example 38. The port of any of the Examples 32-37, wherein the outer wall narrows such that the width of the chamber at the first end of the vane is narrower than the width of the chamber at the first end of the chamber. 
     Example 39. The port of any of the Examples 32-38, wherein the vane comprises a first portion, a second portion, and a gap between the first portion and second portion. 
     Example 40. The port of any of the Examples 32-39, wherein the length of the vane is smaller than the length of the chamber. 
     Example 41. The port of any of the Examples 32-40, wherein the vane reduces noise caused by turbulence within the chamber.