.FLAC VS. .WAV
Apr 6, 2012 6:44:03 GMT
Post by Deleted on Apr 6, 2012 6:44:03 GMT
I asked someone once why I was hearing electronic noises through headphones when the computer did certain things, when there was no sound supposed to be going through the soundcard and all of the system sounds were turned off. Not major noises, just subtle things that were clearly electronic and not mechanical.
This is a grounding (or should I say common reference plane) problem in the PCB (motherboard)/soundcard layout.
These sounds are caused by currents (caused by digital circuitery and fans/motors/diskdrives e.t.c.) flowing through relatively high ground rails/planes/tracks and induce small voltages.
These small voltages are added to the ANALOG signal in the ANALOG plane and it's those voltages you hear.
It has NO influence on the digital CONTENT, it is not changed, bits do not alter. What can happen (and does) is small spikes almost coinciding with transitions in serial data at the moment a transition might occur (determined by the clock frequency) could foul up the timing making DAC's with bad jitter rejection (on board soundcards and cheap soundcards) have deteriorated sound.
Most modern and the more expensive soundcards are (measurably/audibly/arguably) immune to THAT specific kind of jitter.
Data is only assessed at the MIDDLE of bit (determined by the clock being double the data freq) so the data will NOT change because of jitter.
Jitter is ONLY present at the leading and trailing edges where data is NOT analysed.
The clock, however, may be derived from a digital data stream (SPDif) and if this clock is unstable AND the DAC circuit uses this clock without filtering (cheap DAC's do because it is easier to make) this could affect SQ (depends on the severity).
Files themselves are not altered.
Clicks in sound (digital files) always at the exact same place point towards corrupted files.
So you bought a corrupted or badly ripped/encoded file.
My P4 400 MHz PC with cuite a low bus speed and running Ubuntu:
WAV 1-2% load decoding FLAC 2-3% load
a higher percentage of background services is constantly running.
Just pull up the system monitor and see HOW much a PC is constantly doing even if it appears to be idle.
a PC is only idle when it has crashed.
a PC used for data can be considered ideal.
a PC used to produce an analog waveform has issues.
The transition point is where the DAC converts a digital word to an analog value and what happens to that analog signal after that (when connected to an analog system)
It is the exact same point where digital adapts (programmers) experiences end and analog (electronics) world combine.
Most programmers only have some knowledge of the actual hardware.
Hardware specialist mostly do not have the software experience programmers have.
Analog specialists may know something about computer hardware.
There are but few people that know their way in all those fields.
Generally they reside at Hydrogen and for obvious reasons don't walk around in forums where subjectivity is a major asset.