Questions about speaker construction and effects on the frequency response - Page 1
Forum section: electronics / projects

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: February 11, 2021, 01:28:12 pm
content: I ordered a guitar speaker but it sounds way too harsh for my playing.but I've seen Johan Segeborn on youtube sanding down a speaker to make it much less bright and more like... mid-scoopyand then I started wondering,what parts of the speaker influence areas of the frequency response?for example the JBL D120F speakers sounds clean af and they aren't really harshly-bright.and all the clones of those speakers that sound close have the same like... 2.5" or something Coil which seems really bigso does the coil diameter make it sound like it does?what I'm looking for is like a graph of explaining which parts influence what frequencies but I'm quite certain that it's not gonna be that way and instead work all together to make the whole frequency graphdoes the speaker cone thickness/flexibility lower like the top-end output?but common sense would lead me to think otherwise since less weight - higher resonance?so to make a long question short:what makes a speaker sound like it does?

author: penfold
author_rank: Frequent Contributor
timestamp: February 11, 2021, 01:54:10 pm
content: You could start by breaking the problem down into a few distinct areas to help direct your understanding:case 1) you have the "lumped" characteristics such as just the bulk mass and spring constant of the cone and support which determine the basic frequency response of approximate displacement of the conecase 2) there's non-idealities of the cone support which gives some non-linearitycase 3) the radiative efficiency of the cone (still assuming its perfectly rigid), there is an acoustic impedance which is based on the geometry of the cone and it can be more or less efficient at "projecting" sound depending on its frequencycase 4) there are "finer" non idealities caused by the flexibility of the cone and how it distorts (think about the different in using a piece of paper vs a wooden board to fan a fire) in reaction to force from the voice coil (you can make it more flexible by sanding it down so it yields more and is less efficient at higher frequencies)I'm sorry I don't have any precise numbers, but perhaps that will help you direct your research into more distinct areas, looking into acoustic impedance and understanding how horns are used to "match" the impedance of a smaller "radiating surface" to propagate better, aperture sizes and diffraction are also related to this and go on to explain how the angles of cones are designed to give different radiating characteristics - much of acoustics is conceptually analogous to electromagnetics if you want to do some "cross-training" for your brain

author: CaptDon
author_rank: Super Contributor
timestamp: February 11, 2021, 02:43:18 pm
content: You really need to get on a forum dedicated to speaker and cabinet building. The magic of speaker and cabinet response is deeper than celestial physics and subject to the listeners ears and advertising bullshit!!! Every part of a speaker makes it sound the way it does. Speaker science may be bigger than rocket science. There must be 50 flavors of G50 guitar speakers and knockoffs out there and every one sounds different. Me personally, I want my amp and speakers to be as flat in response as possible and for the speakers to have a soft knee as they reach the end of their excursion. That way I can generate any type of distortion I want with pedals/stomp boxes and get a soft pleasing speaker distortion that I can control with volume, but still know if I have to play dead clean with an acoustic guitar for a symphony gig I can be the shining star of cleanliness!!! Look to other dedicated forums for your speaker endeavors and best wishes!! Here is how you know you may be a professional working musician.... (A) Did anyone ever pay you to play? (B) Did they ever pay you to come back? If you answer yes to A and B you may be among those low wage earners called musicians. The difference between a Pizza and a musician, A pizza can feed a family of 4.

author: JohnG
author_rank: Frequent Contributor
timestamp: February 11, 2021, 03:33:58 pm
content: Quote from: ELS122 on February 11, 2021, 01:28:12 pmTo make a long answer short: it depends...More seriously, you can spend years of study and experiment on this, and that's what it will take if you really are interested in understanding what you ask.If you want to approach it analytically, start with learning about vibrating membranes and study up on partial differential equations. Then look at some stuff about electromechanical actuators, interaction with amplifiers circuits, how vibrating membranes transfer energy to the air, how nearby structures (boxes and horns) influence all of the above, and how sound propagates thru the air. Then, start looking at human perception of sound, because it is complex and highly non-linear. After all that, rinse and repeat.If you want to approach it empirically, better start collecting drivers, boxes, and woodworking equipment and start experimenting, including modifying speakers. Oh, and get some means to do sound measurements, and plan to spend some time learning.In practice, you will need to do both. On the speaker forums, you will find a few who do all of the above, but you have to learn who they are and what their biases are, too.Cheers,John

author: Boscoe
author_rank: Frequent Contributor
timestamp: February 12, 2021, 09:45:48 am
content: I’ve spent the last 10 years building speakers. I started off on diyaudio however they are mostly into the voodoo bullshit. I’ll talk about hi-fi but I think you could translate this to guitar speakers.I will be contraversão here, speakers are easy; you just have to bear some key things in mind.1. The bass response. This is determined by the speaker (Thiele parameters), the enclosure and the room. This is simply giving you the rolloff of the response. The amount the speaker can move (xmax) and the power handling determine the peak loudness.2. The crossover of a multi-way system and the high frequency response of the woofer. Normally, people will place the crossover for the woofer at the maximum the dataset response looks good. This would be fine if the manufacturers were generous in the datasheet and we had brickwall filters. Usually people use 2nd order filters meaning the woofer (and tweeter) is perfectly audible for many octaves above and below their acceptable bandwidths. This might result in ‘harshness’ due to woofer break up and overdriving the tweeter. This might be why your system sounds ‘harsh’. Also, the high series resistance of the inductors in the low pass for the woofer dramatically lower the damping factor of the amplifier resulting in very high distortion in the bass frequencies which is often mistaken as just more bass as our ears aren’t very good at low frequencies.3. Good drivers. This is very hard to determine from datasheets. I rely on companies I trust and the physical design of the woofer to determine this. You need a well vented spider and generous magnet with lots of xmax.4. Lots of power from your amplifier. Music is highly dynamic, most amplifiers don’t have the dynamic range to deal with music at reasonable levels.

author: CaptDon
author_rank: Super Contributor
timestamp: February 12, 2021, 02:55:16 pm
content: Writing in one line, I don't understand the comment. I am the king of proper punctuation and sentence order. Never mind that english, either European or American is my second language. Musician rant? I mistakenly assumed you may be a professional musician (I know I am) and could enjoy some musician levity as all professionals in any field enjoy inside jokes about their profession, E.G. 'Dilbert'. Thanks Karen.

author: CaptDon
author_rank: Super Contributor
timestamp: March 15, 2021, 03:25:24 pm
content: Just an outside observation. It looks like you are the king of rant? Can't handle a musicians joke about musicians? B.T.W., I don't use and don't have a grammar checker. All of the 'auto-correct' stuff is turned off also as it tends to mess with how I build my sentences. Have you gotten any useful information about what part of a speaker does what yet? It looks like there was only one or two replies. There are tons of books about speaker enclosures but not a lot of info about construction of speakers. It comes down to listening to other peoples rigs and if they sound pleasing to you, find out what speakers they are using, but even then speakers sound different when placed into different cabinets. But all of that aside, no, I can't tell you what part of a speaker produces a certain sound as they all work together by design. Each part can be tweaked to some degree to tailor the sound.

author: antenna
author_rank: Frequent Contributor
timestamp: March 15, 2021, 04:59:14 pm
content: watch this:this guy covers every aspect of it