Depending how bad this break-up is, this will most certainly show up in linear distortion!
Plenty of examples available.
And since we have intermodulation distortion from the moving parts as well, this problem only will get worse.
Since those two interact with each other.
Yes, the problem is that we don't have proper measurements from most manufacturers.
So we have no clue where to cut exactly.
After a while you get some kind of sense based on experience.
I remembered an old paper by Yamamoto and Tsukagoshi, illustrating the effect of the membrane material (polymer & composite vs paper) on the THD level. Probably, one will have to dive deeply into the theory of plates and shells to explain this phenomena, which goes far beyond the scope of this topic, however, this example demonstrates how important is to optimize membrane design.
Hi Dimitrij,
Could you directly attach the original article here? When trying the link, I only get an overview of the conference articles, presentations & authors, but not the article itself.
Thanx.
Could you directly attach the original article here? When trying the link, I only get an overview of the conference articles, presentations & authors, but not the article itself.
Thanx.
Given that "linear distortion" is in fact the frequency response, what you said above is identical to what I said.
I don't see how?
Again, such problem will show up as regular distortion.
Which can be audible depending on the frequency.
I have seen spikes well within the most sensitive range in our hearing.
Multiply that with IMD.
You were saying that it will not show up as nonlinear distortion?
Again, all this theory is linear. Certainly the cone (shape, material, etc.) will affect the response of the harmonics, but it will not be a party to generating them.
I get what you are saying, and @b_force obviously agrees.
Some where some thing is getting lost in translation cause you guys agree here, and nothing has changed in eithers argument lol
I meant so say that 🙂
We have been here before.
https://www.diyaudio.com/community/...w-distortion-with-a-2-way.334757/post-7429531
You should stop
Linearity condition is valid under assumption, that displacement of the cone is much smaller than its thickness and that the cone support isn't dependent on excitation level, otherwise linearity assumption isn't valid. These assumptions are reasonable for HF drivers, but not for LF drivers.
I don't understand why you ignore experimental data I have provide above. Can you provide any reasonable physical mechanism in the linear framework model explaining why two identical loudspeakers with different cones have a difference of 10 dB of THD ?!
Linearity condition is valid under assumption, that displacement of the cone is much smaller than its thickness and that the cone support isn't dependent on excitation level, otherwise linearity assumption isn't valid. These assumptions are reasonable for HF drivers, but not for LF drivers.
I don't understand why you ignore experimental data I have provide above. Can you provide any reasonable physical mechanism in the linear framework model explaining why two identical loudspeakers with different cones have a difference of 10 dB of THD ?!
I am just asking for clarification because I don't follow what you're saying?
That is probably on a language level because what you are saying doesn't make sense the way I interpret it.
Yes and the funny part that in this context with a very light flappy cone with mechanical impedance mismatch, is that I clearly think about a resonance peak. lol 😀 😀
Which by itself creates those wonderful back EMF issues in the motor, resulting in distortion.
First, I don't know the details of that experiment so I can't comment on it.
There are three major sources of nonlinearity 1) Bl(x); 2) cone compliance k(x); 3)inductance Le(x) - these all vary with cone displacement. In a nonlinear loudspeaker model one has the three nonlinear elements (which generate the harmonic distortion) followed by the linear distortion ( i.e. frequency response) which include things like cone breakup. etc. The cone has a major effect on the linear distortion, almost dominate. Change the cone and this linear distortion changes. The linear distortion acting on the fundamental and the nonlinearly generated harmonics will change the THD measured levels even if the nonlinear aspects of the model don't change. That is how changing the cone will change the THD levels even if there are no harmonics generated by the cone breakup itself.
And yes, cone breakup can go nonlinear if the displacements are large (rare in any good driver), but in reality these breakups have very small displacements - unlike the piston motion which is enormous by comparison.
Hence, I stick by my claim that breakup modes are mostly linear and do not generate significant levels of THD.