Best Cable Option: Streamer to DAC
kijanki It is likely that harmonics of 22kHz come from percussion instruments, that are not continuous by nature.Any percussion instrument is an "continuous" as any violin or other instrument. Consistent with the Fourier Transform, this wave can be recorded. ... 100Hz (drum roll) will give you (modulated) 22kHz with bunch of sidebands spaced 100Hz apart ... Sidebands appear because signal is modulated (not continuous).The signal is analog, it is continuous. The danger here is that anything above half of sampling frequency will, in D/A process, fold into 0Hz and up ...Anything exceeding half the sampling rate is filtered out as part of the A-D conversion process. It doesn't "fold" into anything. You can easily prove this with measurements. |
kijanki ... If you record drum roll it will show individual bursts with silence in between ... When you strike drum once signal is not continuous. There is a silence before and after ...It isn’t clear why you think percussion instruments are not "continuous." They're as continuous as a trumpet - every trumpet player runs out of breath eventually. There’s nothing especially unique about the analog wave produced by percussion instruments. There are analog filters before A/D process but they cannot be very sharp.That something is not perfect does not make it useless. Filters used in A/D conversion can be measured to show essentially perfect rejection of frequencies that would violate Nyquist. ... Nyquist applies only to non-interrupted (continuous) frequencies ...Nyquist and Fourier Transform apply equally to percussion, trumpet, violin and other sounds. Consider that Nyquist is not a theory - it’s a theorem. |
