But at least you recognize that "distortion" may not always be in the speakers. We may just think that it is because we don't know otherwise and that's what everyone says it is.
Skype is a viable option
Yea ... I don't see how that would work.
on the topic of perception i come from a domain that allows me to go from off to incredibly loud
and yes i've experienced "ear distortion" and whenever that happened quick check on the SPL meter at the FOH position allowed me to get a rough estimate of my max level.
many froms of distortion are audible to me long me before i get to my max and a few seem to only make there apperance at lower levels
and yes i've experienced "ear distortion" and whenever that happened quick check on the SPL meter at the FOH position allowed me to get a rough estimate of my max level.
many froms of distortion are audible to me long me before i get to my max and a few seem to only make there apperance at lower levels
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But if you have speaker A vs. speaker B and one thickens up in the bass with level then
you know that it is the speaker. I've done this and it is blatantly obvious.
Again, just because one lowers the SPL at the ears and the perceived distortion goes away is NOT proof that it is not the speakers. For example, if the horn has a lot of diffraction and HOMs then these will be more audible at higher SPLs but not at lower ones. So lowering the SPL at your ears will make this speaker problem go away.
Lidia gets hearing aids for free, so I have a pair even though I am marginal. They are a godsend at noisy restaurants, parties and watching TV with a lot of dialog, (and normal hearing people in the room who think "it's too loud" <- Lidia,) but for music they aren't nearly as good, so I don't use them. A little known fact is that hearing loss occurs from the floor up, the threshold increases, but the top around 90-100 dB tends to not change. So without the aids, music on the loud side sounds just like it always did for the most part.
I always wear hearing protection now, no matter what I do, and even ear plugs at concerts and musicals.
I always wear hearing protection now, no matter what I do, and even ear plugs at concerts and musicals.
Not proof, but a pretty good indication. Sometimes you needn't look far. High SPLs do cause the the ears to distort.
IMHO, you should pay attention to the attenuation tranfer function of these protections because it is not linear at all.
I've seen people, who have worked in very noisy environements with these attenuators, now suffering of cochlear scotomas.
sharing thoughts to clear my head.
i get the whole linear and non linear classification with respect to distortion thing (i think)
amplitude distortion can occur without new frequencies being produced.(so linear)
so now i need help understanding how non linear distortion (you know, the frequency stuff) can happen (my current understanding says the "frequency distortion stuff" comes from the fact that amplitude/frequency is not linear or is this wrong?)
i get the whole linear and non linear classification with respect to distortion thing (i think)
amplitude distortion can occur without new frequencies being produced.(so linear)
so now i need help understanding how non linear distortion (you know, the frequency stuff) can happen (my current understanding says the "frequency distortion stuff" comes from the fact that amplitude/frequency is not linear or is this wrong?)
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Yes, linear distortion means that the frequency response is nonliear, i.e. deviating from a straight line. When you feed such a system sinusoidals of varying frequency but always the same amplitude the output level may not be the same for every frequency. But the output is always a sinusoid. I guess you got that.
Now there are systems whose gain is very dependant on the input LEVEL. E.g. an asymmetry that stretches the positive half cycles in amplitude and crushes the negative ones (or vice-versa). Such a system will not output pure sinusoids anymore. The output signal will consist of the sum of the signal that has been sent in and new frequencies, lower in level, at even integers of the input frequency (named harmonics by the phycisist, therefore the term harmonic distortion). If a system crushes (or even clips) the amplitude symmetrically below and above zero, then the harmonics generated will be at uneven integers of the input frequency. Every system is consisting of a mix of symmetric and asymmetric nonlinearity and therefore the output may have both, even and uneven harmonics.
If you feed such a system with multiple input frequencies you will not only get the aforementioned harmonics for each but the different input signals will intermodulate with each other and also generate a complex mixture of sum and difference frequencies.
Regards
Charles
Edit: Maybe you cold do the inverse (with Excel for instance) and sum a sinusoid and one or two harmonics lower in level and see what the result looks like.
Now there are systems whose gain is very dependant on the input LEVEL. E.g. an asymmetry that stretches the positive half cycles in amplitude and crushes the negative ones (or vice-versa). Such a system will not output pure sinusoids anymore. The output signal will consist of the sum of the signal that has been sent in and new frequencies, lower in level, at even integers of the input frequency (named harmonics by the phycisist, therefore the term harmonic distortion). If a system crushes (or even clips) the amplitude symmetrically below and above zero, then the harmonics generated will be at uneven integers of the input frequency. Every system is consisting of a mix of symmetric and asymmetric nonlinearity and therefore the output may have both, even and uneven harmonics.
If you feed such a system with multiple input frequencies you will not only get the aforementioned harmonics for each but the different input signals will intermodulate with each other and also generate a complex mixture of sum and difference frequencies.
Regards
Charles
Edit: Maybe you cold do the inverse (with Excel for instance) and sum a sinusoid and one or two harmonics lower in level and see what the result looks like.
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Easiest is to think about clipping. Or think about an amplifier that (grossly) loses gain as amplitude increases. Now, go back to the link I gave, and try a f1 of 20 hz and 40 hz f2, ramp up the intensity from 0 to 0.25. The summed response looks a whole lot like the top of the sinusoid was flattened, just like losing gain with signal amplitude.
maybe i'm still not using terms correctly/properly.
yes i think i understand that an amp with a non linear transfer function can have high harmonic distortion.
i'm i wrong to think that in a loudspeaker the presence of high levels of harmonic distortion "are" an indicator of lousy linear response
yes i think i understand that an amp with a non linear transfer function can have high harmonic distortion.
i'm i wrong to think that in a loudspeaker the presence of high levels of harmonic distortion "are" an indicator of lousy linear response
An interesting conjecture but there is no direct connection between the two even though in a very bad driver one could expect plenty of both.