Yeah any single number is too much simplification 
perhaps there is some correlation with mms and sound quality if one is listening to the high frequency stuff, like clarity or impulse response or speed or what ever "quality", frequency response.
For example smaller voice coil inductance would make more high frequency output, it would be less wire, less mass. But then again, perhaps less power handling capability and perhaps less force in the motor, perhaps less xmax and so on, which would take away low frequency performance. Also higher Fs unless softer suspension, which would probably affect box size and so on, less robustness, million things. In general, some kind of compromise between low frequency and high frequency performance, size, power handling. It depends on application what kind of a compromise fits. Perhaps mms is some kind of an indicator, as good as any other single number that feels relevant.
perhaps there is some correlation with mms and sound quality if one is listening to the high frequency stuff, like clarity or impulse response or speed or what ever "quality", frequency response.For example smaller voice coil inductance would make more high frequency output, it would be less wire, less mass. But then again, perhaps less power handling capability and perhaps less force in the motor, perhaps less xmax and so on, which would take away low frequency performance. Also higher Fs unless softer suspension, which would probably affect box size and so on, less robustness, million things. In general, some kind of compromise between low frequency and high frequency performance, size, power handling. It depends on application what kind of a compromise fits. Perhaps mms is some kind of an indicator, as good as any other single number that feels relevant.
Transverse waves propagating through a material don't 'cause' resonances. Resonances are standing waves. Termination causes reflection of propagating waves and thus causes standing waves. I stand with you when you state a proper termination is of importance in handling resonances.
But this all is of no importance when there are no standing waves. The proper termination for minimising standing waves likely has negative influence on the non-resonant behaviour of the cone though.
Could you give a practical example of resistive behaviour at both ends of the cone? Both the resistance on angular motion and transverse motion should be addressed imho. And it would be nice if you could explain why cone mass alone is a determining factor.
I think a lot of us know of quite a few cones that act as a lumped mass up to several kHz. It actually is not that hard to design a loudspeaker that uses only cones that act as lumped masses aka move pistonic. To me it really is a design tradeoff.
Cones exhibit resonant behaviour when improperly terminated - same as a length of coax. Most - if not all - cones are inadequately terminated at/by the surround (which is deliberately designed to be relatively low loss in order to handle the large excursions at low frequencies).
Lighter cones require less damping by the surround, so are likely to exhibit better behaviour - all other things being equal. Because there's less of a mismatch between cone and its termination.
Don't forget I'm referring in particular to the OP's large drivers which feature in his linked blog.
Lighter cones require less damping by the surround, so are likely to exhibit better behaviour - all other things being equal. Because there's less of a mismatch between cone and its termination.
Don't forget I'm referring in particular to the OP's large drivers which feature in his linked blog.
For anyone thinking a typical driver cone behaves as a simple piston at medium frequencies, take a look here:
https://www.klippel.de/fileadmin/kl...ement_and_Visualization_Cone_vibration_06.pdf
https://www.klippel.de/fileadmin/kl...ement_and_Visualization_Cone_vibration_06.pdf
Hello there, frankly speaking i do not understand the point of the thread opener with bad in math and the lack of measurement equipment. In the meantime the thread opener would have been able to save a lot of money and time with this: instead of buying dozens of different speakers to buy a decent audio measurement system like as an example the CLIO pocket that comes with a well calibrated microphone and a very well engineered USB measurement interface hardware. The interesting part of the listening tests starts when the measurement part is finished and one was able to get a decent frequency response curve on axis and off axis in at least 5 degree steps until 90 degrees when you want to check it thoroughly. The pain of this: it is much more work than to listen and judge with very well - meh - blah statements. Sorry to be so honest but i could not deny myself to post this - all only my two cents worth
I take it you keep generalizing in your assumptions. And not answering questions. If now you state actually less damping at the surround would be beneficial, I lost you in the first posts.
Things are not equal in the real world. Light and stiff cones such as the honeycomb Eton, the sandwich Podzus Görlich and metal cones in general do exhibit strong resonances that hardly can be controlled by surround damping. Light and flexible cones tend to flex, the surround resistiveness cannot contribute so much. That’s why I pointed at PP cones such as Harwood uses. So essentially driving a cone into resonance territory will always lead to a compromise. And don’t get me wrong, very adequate compromises can be reached.
But, cones don’t always exhibit resonant behaviour. Only if you feed the driver the right signal. For sure you can choose not to. Or only in a limited way. That’s why we discuss multi-way in this section.
@keithj01 - Now I am a little confused about what you are getting at... You say you are not talking about damping the main resonance. But a few posts back you say
Are you talking about the first mode resonance here, when you made that statement? Because here you did not qualify the statement... So when I read it, I assumed that "resonant behavior" means all resonant behavior including the first mode. Your statement implies that with proper termination, a cone can be resonance free... But I don't think that is true. All cones will exhibit a resonance at some frequency. Surround damping can reduce the amplitude, but it can't eliminate it.
I think it's important for people to understand the difference between piston region and when a loudspeaker (or any other acoustic system for that matter) goes out of this piston region and material resonances start to happen.
The surround is a separate part from all of this, and is indeed a matter of acoustic impedance mismatch (or mechanical rather I guess), pretty much the same as electrical impedance mismatch.
Btw, this mismatch seems to be a lot stronger with lighter (paper) cones.
But again, go read those books, which saves pages and pages of offtopic discussions that go absolutely nowhere.
I guess some people just like to spend time because they are bored?
The surround is a separate part from all of this, and is indeed a matter of acoustic impedance mismatch (or mechanical rather I guess), pretty much the same as electrical impedance mismatch.
Btw, this mismatch seems to be a lot stronger with lighter (paper) cones.
But again, go read those books, which saves pages and pages of offtopic discussions that go absolutely nowhere.
I guess some people just like to spend time because they are bored?
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The whole thread is not about solid engineering (theory-measure-falsificate-adjust theory and so on) but tends to pointless discussions about taste and vague statements obviously needed to defend certain assumptions (lighter cones are better, I’m waiting for the claims low mechanical damping is better, or hand crafted paper is better, or Alnico is better)
That by itself doesn't mean anything to begin with.
Everything has its pros and cons.
It will always be some kind of compromise one way or another.
I actually prefer the "listened and liked or disliked" type of review. That is how I design a speaker system also. I listen to each driver and only use the ones that actually sound good to me. I have found that response graphs are not very helpful in many cases.
I like light cones with minimal damping. I think that many drivers are too heavily damped. This may be an attempt to get a flat measured response, or maybe someone else simply prefers that sound. Problem is that it also tends to reduce low level details.
Paper cones with paper surrounds and voice coil formers are my favorite, I think that the matching materials will pass energy waves better. A differing former or surround material is very much like an impedance mismatch to me.
I noticed that you didn't like the Eminence Legend 1028K. I was impressed that you tried it. It meets my spec, but I haven't heard that one. I have had good results using other Eminence guitar drivers for music.
I like light cones with minimal damping. I think that many drivers are too heavily damped. This may be an attempt to get a flat measured response, or maybe someone else simply prefers that sound. Problem is that it also tends to reduce low level details.
Paper cones with paper surrounds and voice coil formers are my favorite, I think that the matching materials will pass energy waves better. A differing former or surround material is very much like an impedance mismatch to me.
I noticed that you didn't like the Eminence Legend 1028K. I was impressed that you tried it. It meets my spec, but I haven't heard that one. I have had good results using other Eminence guitar drivers for music.
I believe it is true if it is 10% the power, even 1% the power. But at 1 millionth the power? We are now talking about essentially 1mV level here. We are trying to reproduce 60db from a system that is designed to reproduce 120db at 1W. There are other mechanism involved, static resistance from friction, hysterisis. etc. To date I don't believe I have seen data from any compression driver at 1uW. But yet if that is where a high hat with a brush or a triangle in an orchestra lives. The so called details.Hi,
transducers ought to be most linear the less there is excursion, so most truthful with the micro watt level. I have no reason to doubt this with any drivers because all parameters have least variance the less there is excursion, iow the driver/enclosure system is most linear with least movement; both electrical and mechanical, air in any chambers and so on, very little heat etc. On very low levels relationship to ambient noise changes, and how your hearing system detects it all of course. Perhaps try with mic, which can hear so low levels that we cannot
Don't get me wrong, I am all for testing and performance. They are good for telling you how a speaker performs at the said test condition but it doesn't tell you how it will play music. For example speakers are tested at 2.83V for 1 Watt equivalent, that is primarily for matching drivers and understanding how sensitive it is. If you wanted to see how well a speakers plays music, I might choose a different test condition as reference. For example instead of 1W/1m, I might choose average loudness at 80db Average at 1 metre. Or if I am interested in details, average volume of 60db at 1m. How it reproduce at loud levels, maybe 90db. All the testing for loudspeakers are imported concepts from electrical engineering. Speakers are mechanical systems that don't behave like electronic system. Example, there is no such thing called inertia and momentum in electrical engineering. Speakers will always produce sine wave in nature because it is part of physics on what we call a simple harmonic motion.
So my contention is if we are to use tests to determine how it will sound, we need a new whole set of tests, tests that hasn't been invented yet...
Oon
Yes, but that doesn't seem to be available - we're talking about the OP's collection of drivers. Damping at the surround is usually minimised to allow freer cone movement at low frequencies and larger excursions.
"Main resonance" is different from resonant modes within a cone (which is what I've been talking about). It's the result of having a lumped mass (which is what the cone is, to all intents and purposes at low frequencies), interacting with the compliance of the suspension. It's something which is quite adequately damped by voltage drive, in the right enclosure (as we all know).