Converter THD+n.

[Teddy Ray]

Originally Posted by haryy

What is its scale?
If 1 channel produces -108db, then what happens when you add 50 tracks?
Is it a 3db per doubling?

Stacking Theory

[Ethan Winer]

Originally Posted by haryy

If 1 channel produces -108db, then what happens when you add 50 tracks? Is it a 3db per doubling?

Yes, but that's only for noise. In the thread Teddy linked I explain why this doesn't hold for distortion on different tracks. Track distortion is not coherent so it doesn't add.

--Ethan

[haryy]

So there's no further degradation as for the THD+n regardless of number of (converted from analog) tracks?

[Ethan Winer]

Yes, as I said above, distortion on different tracks does not add because the tracks are different and so create different artifacts.

--Ethan

[haryy]

Isn't it the same when there's a signal and when there's silence? (just asking)
Does the thd "modulates" the signal so it takes a different form for every recording we make?

[Ethan Winer]

Originally Posted by haryy

Isn't it the same when there's a signal and when there's silence?

When there's silence that would only be noise. Distortion happens only when there's a signal.

Does the thd "modulates" the signal so it takes a different form for every recording we make?

Distortion shows up as additional frequencies that were not present in the original signal. There's THD and also IM, though IM is generally more damaging because the added frequencies are not necessarily related musically to the original.

--Ethan

[haryy]

InterModulation distortion?

It's not as "harmonic" as the THD you mean (?)
But it doesn't add also, does it?

[Ethan Winer]

Intermodulation - Wikipedia, the free encyclopedia

The above gives a good explanation. Don't worry about the math, just see the first paragraph.

Actually, this is better:

What is Intermodulation Distortion? - IMD - Definition and Explanation of IMD

[haryy]

Thanks for your time and help.