
bouldersoundguy
Well-known member
I never understood intersample peaks. If anyhing happens between the samples, it would be happening at a frequency above nyquist and would be filtered out anyway. What am I missing?
As you say the low pass filter takes out the higher frequencies. Sharp corners on waveforms indicate high frequencies, like if there were straight lines drawn from sample to sample. So the low pass filter rounds off those corners. If two of those corners are at or very near 0dBFS then the filter may not allow the waveform's line to turn that corner sharply enough to avoid going over.
You don't get this with a simple A/D/A path as the output voltage = the input voltage. But as soon as you start processing in the digital domain you can create digital audio that can produce analog peaks higher than what 0dBFS represents. Some converters have headroom for this and others don't