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0 pointstonecluster10y ago0 comments

"...and cause inter-modulation products in the audible range." AFAIK, this is true in acoustic environments under conditions as described in the original post.

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darkmighty10y ago· 2 in thread

There are no inter-modulation products in the sense rplst8 expects. The interaction of waves of 1000Hz and 1001Hz doesn't produce 1Hz waves in linear media.

Even if it did produce some new frequencies through some non-linearity (which is negligible in most environments afaik), the recording equipment would capture the low frequency waves produced by those interactions. So the only question is whether there are significant non-linearities in our hearing system, and the overwhelming evidence is no again afaik.

rplst810y ago

The recording equipment won't necessarily pick it up. If the microphones are place very close the instruments relative to the other instruments creating the interaction.

darkmighty10y ago

If no recording equipment would pick it up, no human would pick it up either.

Quoting xiphmont

> Once you're driving air so hard it becomes nonlinear, thus introducing intermodulation distortion in the air, that distortion produces actual audible-range distortion products. And because the distortion you're hearing is in the audible range, a recording will sample and reproduce it accurately.

> You're hearing the audible _result_ of IMD, you're not somehow listening to the distortion curve itself.

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