Good combo of software/hardware for doing audio measurements - Page 1
Forum section: electronics / testgear

author: davorin
author_rank: Unknown
timestamp: September 25, 2015, 02:08:15 pm
content: I'm looking for a Software/Hardware solution to do audio measurements with either a PC running Win81 or Ubuntu.For Software I've checked the ARTA and the RMAA packages, which could do spectrum and THD stuff...Or someone knows of other Software?RMAA:http://audio.rightmark.org/products/rmaa.shtmlArta:http://www.artalabs.hr/For the Hardware, which external USB soundcard would be a good choice for that and does not cost a fortune?

author: quantalume
author_rank: Unknown
timestamp: September 25, 2015, 02:55:27 pm
content: I recommend ARTA as it has always worked well for me, and the user interface is pretty reasonable, unlike some other offerings in this category. I really want to like Daqarta (http://www.daqarta.com/index.htm), but I just can't get used to the UI. There is also Visual Analyzer (http://www.sillanumsoft.org/) and TrueRTA (https://www.trueaudio.com/rta_abt1.htm).Here is a comparison of USB sound cards, geared towards real-time analysis:http://www.daqarta.com/dw_gguu.htm.I have the Behringer UCA202, and it works really well for audio performance measurements. I don't remember what the noise floor on my particular unit is, but the corresponding THD is somewhere around 0.01%. Not bad for $30. It has phono jacks for input and output, another bonus compared to the 3.5 mm TRS jacks on other units.

author: Alex Nikitin
author_rank: Super Contributor
timestamp: September 25, 2015, 03:47:41 pm
content: I useAudioTesterand a modified RME Digi 96/8 PAD card (however this card would only work on Win XT). There are some samples of AudioTester results onmy web site. My hobby is tape recorders and I do lots of various sweep measurements with AudioTester.Here, for example, 104 cassette tapes measured for 3HD v Level at 315Hz.CheersAlex

author: davorin
author_rank: Unknown
timestamp: September 25, 2015, 05:51:21 pm
content: Think I'll go with the Creative Sound Blaster X-Fi HD Hardware for my PC....I've downloaded already the ARTA and RMAA Software and tried it out with the UMIK-1...Now just downloaded the AudioTester Software....Are there any more professional USB ADC/DAC converters out there in the US$ 200 - US$ 300 range?

author: commongrounder
author_rank: Frequent Contributor
timestamp: September 25, 2015, 05:59:24 pm
content: Check out the QuantAsylum QA400 audio measurement interface with software. It is a souped up USB audio device optimized for distortion measurements, etc.https://www.quantasylum.com/content/Products/QA400.aspxGood bang for the buck.

author: DimitriP
author_rank: Super Contributor
timestamp: September 25, 2015, 06:15:40 pm
content: Quote from: Alex Nikitin on September 25, 2015, 03:47:41 pmDid you measure the frequency response of these tapes?

author: davorin
author_rank: Unknown
timestamp: September 25, 2015, 06:19:39 pm
content: Yes I stumbled upon this one today as well (o;Looks very professional...and what I like the most....BNC connectors...and not cheap RCA or even 3.5mm jack connectors ;-)Seems though their device won't register as a regular audio device within Windows...so it is fixed to their software only...Just read in their forum....a QA405 is in the builds...differential inputs and better ADC/DAC

author: commongrounder
author_rank: Frequent Contributor
timestamp: September 25, 2015, 07:57:46 pm
content: The QA405 has been in the works for a while,and the specs sound promising. For me, the dedicated Windows driver is not a deal breaker because I would be using it exclusively for measurements and not audio recording/playback. I do hope they include decent input protection, as any good piece of test equipment should have.

author: davorin
author_rank: Unknown
timestamp: September 25, 2015, 08:03:24 pm
content: Someone found in the forum the same product with a different name called FP8400....they also sell other audio hardware:http://www.fpinstrument.comFor me it is also not a killer if it can't be used as a regular audio interface....but definitively being able controlling from other OS would be great if they released the API used for USB control.

author: Alex Nikitin
author_rank: Super Contributor
timestamp: September 25, 2015, 08:22:52 pm
content: Quote from: DimitriP on September 25, 2015, 06:15:40 pmThere is no such thing as a frequency response of a tape, only a pair - tape + recorder/playback machine. Tapes differ by their saturation levels, distortion, noise, durability etc etc, however almost any tape can produce a flat response with a correctly aligned recorder. There are recorders which can get a flat response over 20Hz-20kHz on any half-decent tape with help of sophisticated tuning systems. Here is a couple of graphs (taken with AudioTester) . One is a family of frequency response curves for a modern Sony HF cassette, another - for a 35-year old Sony cassette. Except for the difference in saturation at high levels and a bit of difference over 20kHz the responses at -20dB are flat +/-1dB from 20Hz to 20kHz and extend well over 20kHz. And that particular deck can do the same with 99% of cassettes.CheersAlexOn the graphs: -10dBFS = 0dB DIN (250nWb/m @315Hz).Sony 2012:Sony 1978:

author: Berni
author_rank: Super Contributor
timestamp: September 25, 2015, 08:39:39 pm
content: I use the Visual Analyzer software:http://www.sillanumsoft.org/As for the hardware i made my own ASIO USB sound card with galvanic isolation and the best audio ADC i could get from TI.

author: davorin
author_rank: Unknown
timestamp: September 25, 2015, 08:52:35 pm
content: How much for your hardware? (o;I assume it's not an open source project?

author: Timur Born
author_rank: Regular Contributor
timestamp: September 25, 2015, 09:03:44 pm
content: Quote from: Berni on September 25, 2015, 08:39:39 pmIt's free for the time being and it brings quite some features. Unfortunately it is using Windows audio (MME Wave it seems), with no options for ASIO (or anything else). It seems to max out at 96 kHz and the Windows mixer messes with sample-rate conversion anyway. Still a nice free program. Interestingly its tone-generator is limited, even though the "Pro" version is not available.The trial-version of DFFS3 offers a tone-generator that can be used for unlimited time. I once (years ago) compared its noise-generator to various freeware ones and found it superior.http://www.ymec.com/products/dssf3e/index.htm

author: Berni
author_rank: Super Contributor
timestamp: September 25, 2015, 09:14:44 pm
content: Quote from: Timur Born on September 25, 2015, 09:03:44 pmYes you need to tweak the windows sound settings a bit in order to make it work correctly. It does not need to have support for ASIO, just set the default settings in windows and in the software the same and it should not resample. Also it does work at 192k if you manually type it in and hit enter.Quote from: davorin on September 25, 2015, 08:52:35 pmI never totaled up all the parts on it but it certainly was not cost optimized. I have a few left over bare PCBs(4 layer) for it but it might take you a while to get all the parts together and a lot of them are QFNs with head pads under them so not the most friendly thing to solder.

author: davorin
author_rank: Unknown
timestamp: September 25, 2015, 09:18:37 pm
content: Well...soldering I could do with VPS as I have few kilograms of Galden LS-230 left....The PCB looks really professional....never though if going commercial?

author: Timur Born
author_rank: Regular Contributor
timestamp: September 25, 2015, 09:34:45 pm
content: Room EQ Wizard can measure various things and is free:http://www.roomeqwizard.com/features.html

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: September 25, 2015, 09:39:58 pm
content: I use Audiolense which can output a FIR filter for room correction. Not a complete 'suite' but I like it for what it is

author: Timur Born
author_rank: Regular Contributor
timestamp: September 25, 2015, 09:54:40 pm
content: This one may be useful for test-tones. Didn't test myself yet, though.http://www.wavtones.com/functiongenerator.php

author: Berni
author_rank: Super Contributor
timestamp: September 25, 2015, 09:59:47 pm
content: Quote from: davorin on September 25, 2015, 09:18:37 pmI use solderpaste applied with a toothpick and hot air to solder down the QFNsIts not commercial, just a tool i developed for testing audio equipment during development. So far it can test distortion down to 0.0003% THD.

author: davorin
author_rank: Unknown
timestamp: September 25, 2015, 10:05:03 pm
content: Do you mind to share the schematics?

author: Timur Born
author_rank: Regular Contributor
timestamp: September 25, 2015, 10:22:42 pm
content: Quote from: Berni on September 25, 2015, 08:39:39 pmI want that!Is it purely USB powered so that you can use a laptop on battery to have a floating measurement system? And did you write the drivers yourself or got a chip + generic drivers?

author: Berni
author_rank: Super Contributor
timestamp: September 25, 2015, 10:46:44 pm
content: Sorry not sure if i can post the full schematics on the internet but i can share details about it.The isolated side is designed to run from batteries or external power. There is a isolated DC/DC to charge them from USB power but that was not fully implemented. I designed it to do floating measurements using a regular desktop PC that cannot be easily floated.

author: Timur Born
author_rank: Regular Contributor
timestamp: September 25, 2015, 11:26:58 pm
content: Is (desktop PC components) noise traveling down the USB ground line a problem? Especially when you playback (test-tones) via XLR cables (pin 1/shield connected) to equipment that uses 3-prong power-plugs (earth)?Usually this kind of noise is very low in level, but it can be pushed by certain PC load states (and sometimes CPU c-states). Incidentally I would use an interface like yours (connected to a floating laptop running on battery power) exactly to measure this kind of noise coming from desktop PCs. That being said, a bus-powered RME Fireface 400 works quite well for me, too. It's rated 110 dB RMS dynamic range usually are good enough.

author: Berni
author_rank: Super Contributor
timestamp: September 26, 2015, 06:57:40 am
content: Quote from: Timur Born on September 25, 2015, 11:26:58 pmPower coming from USB will always be noisy but if you have good input filtering and regulation it should not be too big of a problem. Its worse when you try connecting stuff inside the PC. I built a home theater PC for the living room with a 5.1 amplifier built in to the same case and had at first a noise problem where i could hear CPU load in the speakers. Some rewiring to get the grounds sorted out fixed that.(I was using a PCIe sound card with single ended outputs)As for ground loop noise, it should be taken care of XLRs differential nature but nothing has an infinite common mode rejection. It depends a lot on the power supplies in the equipment and how they are plunged in (Especially bad if they are plugged in to two different wall outlets rather than a power strip) and other equipment near by that might be pushing currents in to the earth wire. So i just play it safe and float my instrument to be sure. When you are looking at -140dB signals you can pick up all sorts of noise(Even radiated noise from CCFL lamps if they are near by).

author: Alex Nikitin
author_rank: Super Contributor
timestamp: September 26, 2015, 08:46:00 am
content: Here is the FFT at -10dBFS of one of my two RME cards (internal PCI, BTW), single-ended input from the (external) Amber 3501 generator (the internal RME DAC produces about 0.0004% THD at 1kHz) . No question, one can do better, however for me it is good enough.CheersAlex

author: SeanB
author_rank: Super Contributor
timestamp: September 26, 2015, 09:44:29 am
content: I am looking to upgrade PC audio slightly, so will grab a standard component amplifier from storage, and put into it a Toslink audio output unit I got a while ago ( with the world's worst wall wart PSU, but I knew that already) and then power it off the internal rails with a 5V regulator, leading the optical cable out to an external USB card with toslink output. Should improve things a little by removing the PC noise.Originally i used a first generation ISA Sound Blaster Pro, and to reduce the noise I put some copper foil shielding on each side of the card connected to the card grounding on the mounting ear. Improved things a lot, though I had to leave a slot open on the one side and put it on the end of the ISA bus.

author: _Wim_
author_rank: Super Contributor
timestamp: September 26, 2015, 11:20:21 am
content: Quote from: Berni on September 25, 2015, 08:39:39 pmWow, I would be interested in one of these as wel...

author: _Wim_
author_rank: Super Contributor
timestamp: September 26, 2015, 11:21:44 am
content: As to software, I also use ARTA and sometimes Holmimpluse (for loadspeaker measurements only).

author: jackenhack
author_rank: Contributor
timestamp: September 26, 2015, 11:42:18 am
content: I'm thinking of getting the PCM4222EVM Evaluation boardhttp://www.ti.com/tool/pcm4222evmand connect it to a USBStreamerhttp://www.minidsp.com/products/usb-audio-interface/usbstreamer. The specs on the PCM4222 are insane! And feeding it with a really low noise power supply. The PCM4222 Evaluation board costs around $145 and the USB to I2S input costs around $100.

author: davorin
author_rank: Unknown
timestamp: September 26, 2015, 11:50:00 am
content: Hmm...XMOS....sounds familiar....I must have some XMOS eval boards lying around here with USB and audio Interfaces (o;

author: jackenhack
author_rank: Contributor
timestamp: September 26, 2015, 11:58:50 am
content: Quote from: davorin on September 26, 2015, 11:50:00 amEbay is full of XMOS I2S to USB, but their only for output to DAC, not to ADC unfortunately. I really want to get a really good test rig for audio measurements, but except for the QA400 there isn't anything out there. Of course, I could sell my body to science, and have enough money to buy a cable from Audio Precision.

author: Timur Born
author_rank: Regular Contributor
timestamp: September 26, 2015, 01:01:16 pm
content: Quote from: SeanB on September 26, 2015, 09:44:29 amYes, putting a non conducting optical link in between gets rid of all the PC noise. I am using this combination myself for daily use, connecting all kinds of stuff (including an old X-Fi) to a Fireface UC and then going optical to a Babyface with its big knob right in front of me for easy volume control.QuoteProblem nowadays is that the *ground* itself is full of noise. A high performance graphic-card will pollute all grounds on your mainboard and feed its noise to earth over every possible cable connection. Then the combination of how you have your devices connected to the same or different power-strips decides about how much of the noise if audible on 3-prong connected speakers (simple 2-prong desktop ones usually don't suffer). There can be cancellations and there can be summing of the same noise signal traveling via different path. For example:PC -> DVI -> display -> power-strip 1 -> power-strip 3PC -> USB -> audio interface -> speaker -> power-strip 2 -> power strip 3If you are only suffering from noise on the speakers (there can be other issues) then something as simple as breaking pin 1 (shield) on an XLR cable (or S on a TRS) will help. Of course you could risk your life by getting rid of earth, but that really isn't the solution out of the various that one should consider. Notice how the workaround are more or less the same as the ones used to get rid of mains 50/60 Hz hum loops.Another software I know about:http://www.hpw-works.com/index.phpBtw, it seems that none of these programs offer brown noise generation, except for DFFS3?!

author: dom0
author_rank: Super Contributor
timestamp: September 26, 2015, 01:41:48 pm
content: QuoteYou don't get rid of earth by lifting the shield of asignalcable. You do however remove that earth connection which might improve things, if the differential input amp is good enough.

author: Timur Born
author_rank: Regular Contributor
timestamp: September 26, 2015, 02:01:11 pm
content: You misinterpreted my sentence, and my writing may not be top of the game sometimes (non-native here).I meant: the simple solution is to break pin 1 XLR, the dangerous - and different - solution would be to break earth (on the power-plug). So two alternatives in two sentences, no direct connection between the two.

author: Berni
author_rank: Super Contributor
timestamp: September 26, 2015, 08:33:18 pm
content: Yes XMOS is the most popular solution for async USB audio right now. Does work pretty well to be fair.Connecting one of those XMOS interfaces to the PCM4222 eval board would give you a pretty good system if you ask me, but what "Alex Nikitin" has is pretty much as good as you can get. Past about 0.0001% you sort of get in to the range there the internal noise of opamps might start becoming the limiting factor even if you use the best opamps out there as well as things like thermal resistor noise becoming an impenetrable wall.

author: Timur Born
author_rank: Regular Contributor
timestamp: September 26, 2015, 09:20:09 pm
content: What do you want to measure anyway? Your onboard audio may be sufficient, maybe coupled with Asio4all if you need smaller latencies (and use a software that supports Asio).And increasing rise times on your graph displays already goes a long way to average out noise (floor) from any (semi-)constant signal that you want to measure.

author: jackenhack
author_rank: Contributor
timestamp: September 27, 2015, 04:00:53 am
content: Quote from: Timur Born on September 26, 2015, 09:20:09 pmFor me, I just want the test equipment to be better than the DUT. I had a EMU 0404 USB external device that actually was very good, but the drivers for it was crap, and to get a consistant input was almost impossible because of a bad implementation of the rotary encoders for the input. I want to be able to see if my modifications has a positive impact on the tested device. It would be nice to have a calibrated input so real measurements could be done (which excludes RMAA), but that's not my main priority.

author: Alex Nikitin
author_rank: Super Contributor
timestamp: September 27, 2015, 07:39:18 pm
content: Quote from: Berni on September 26, 2015, 08:33:18 pmAs a side note - you don't need quotation marks, it is my real name.CheersAlex

author: Berni
author_rank: Super Contributor
timestamp: September 28, 2015, 07:05:31 am
content: Quote from: Alex Nikitin on September 27, 2015, 07:39:18 pmOr so you would want us to believeJust joking.

author: davorin
author_rank: Unknown
timestamp: September 28, 2015, 07:44:27 am
content: Already got feedback from Fast Precision:Quote

author: davorin
author_rank: Unknown
timestamp: September 28, 2015, 09:26:45 am
content: Hmm....if I recall correctly....I never saw anything about phase errors in any of the software I tested....Guess it would be difficult with USB ADC/DAC devices due to latency...

author: hayatepilot
author_rank: Frequent Contributor
timestamp: September 28, 2015, 09:50:08 am
content: I use a miniDSP UMIK-1 for measuring audio.It has an almost unbeatable bang per buck since it comes fully individually calibrated. WithREWyou can even use it as a sound level meter for absolute measurements.And since it has the soundcard built in, you don't have to worry about a preamplifier and gainstructure.If you have a HDMI capable AV-receiver you don't even need an analog audio output since you can adress all channels of even a 7.1 system individually over HDMI.Guide to HDMI measurements using the UMIK-1For non professional use, this is more than you ever need.Greetings

author: Timur Born
author_rank: Regular Contributor
timestamp: September 28, 2015, 10:03:41 am
content: If your are into iOS devices then this one combined with their respective software looks neat:http://www.studiosixdigital.com/audio-hardware/iaudiointerface2/iaudiointerface2-informatio.htmlhttp://www.studiosixdigital.com/audiotools/

author: davorin
author_rank: Unknown
timestamp: September 28, 2015, 11:20:23 am
content: I also got the UMIK-1...great device at a great Price :-)So alread two of those microphones in Switzerland then (o;Hmm...seems not many Linux Software out there for doing frequency/phase repsonse and THD measurements...

author: Tim F
author_rank: Regular Contributor
timestamp: September 28, 2015, 12:14:45 pm
content: Using a E-MU 0204 USB for DAC/ADC duties and a Dayton Audio EMM-6 mic for measuring speakers here. I used mostly self written MATLAB scripts for software, but use HOLMImpulse to generate sweeps since it does a good job of automating the sweep generation, playback, recording, recording offset detection and saving the recording to a wav file.http://feleppa.com.au/speakermeas.html

author: davorin
author_rank: Unknown
timestamp: October 05, 2015, 07:41:34 pm
content: My QA400 arrived this morning now in Switzerland...ordered it last Wednesday only as I was promised I would be in the first round to get hands on the new QA405 beta device coming this autumn...So will keep you posted on my experience with this device....

author: davorin
author_rank: Unknown
timestamp: October 07, 2015, 05:04:10 pm
content: Hooked it up to my home PC now running Win 8.1 x64....Calibration went through fine...not on VMWare Fusion though....But a simple FR measurement runs forever and only left Signal and clipping LEDs are blinking...nothing else Happening....

author: davorin
author_rank: Unknown
timestamp: October 07, 2015, 05:26:48 pm
content: My fault (o;The first installed 1.055 Version doesn't get roperly replaced by the newer 1.22 Version...also it doesn't complain during Installation...just installs new files and keeps existing ones (o;So be sure to remove an older Installation before...

author: linux-works
author_rank: Super Contributor
timestamp: October 07, 2015, 06:03:01 pm
content: a sound card that I was told is about as good as it gets for pc's is the juli@ by ESI. the pci is the classic card but there is a pci-e as well.an audio designer friend of mine swears by this card for its a/d and d/a.other interfaces known to be high quality: emu 0404usb and m-audio firewire audio interfaces (old by now and no one uses firewire, but its still a good reference audio module).

author: davorin
author_rank: Unknown
timestamp: October 07, 2015, 06:08:25 pm
content: Well I don't have any computers with PCI or PCIe slots...only small Intel NUCs sitting below the monitors (o;My dream device would be a rack based device with slots for individual in/out interfaces, either analog...or what I miss...SPDIF/I2S interfaces for measuring also own A/D and D/A designs...At least I could use my HP 3488A switch with the VHF card to remotely switch analog inputs/outputs.......ah yes...a A/D-D/A card for HP 3488A would be nice...but probably GPIB would be too slow then....

author: linux-works
author_rank: Super Contributor
timestamp: October 07, 2015, 10:03:51 pm
content: the card is the important part, not the pc. you build the pc around the card!you may be able to find those pci cards used cheaply. and pci slot pcs are cheap, too, even fanless ones.that's what I recommend. not using 'on hand' stuff but if you want good audio measurements, you get the right card and go from there. anything else and you might as well use any consumer 'sound card'.

author: jhenderson0107
author_rank: Regular Contributor
timestamp: October 08, 2015, 02:00:18 am
content: I use and recommend the rackmount MOTU 896mk3http://www.motu.com/products/motuaudio/896mk3as an eight-channel USB"soundcard" in conjunction with SoundEasyhttp://www.bodziosoftware.com.au/. This combination, in conjunction with a few simple jigs and a calibrated microphone is sufficient for all of my speaker building and testing requirements. SoundEasy is the most powerful design tool for the development and testing of loudspeakers that I've ever used.