Phil Leigh;538958 Wrote: > I haven't got time to get deeply into this a the moment but: > > 1) if you can only hear a very very quiet sound with your ear pressed > against a driver I can absolutely guarantee you can't hear it at all at > 1 metre/3 feet away. The inverse square rule sees to that. > > 2) any sound in the 3 least significant bits is going to be totally > masked by other higher level sounds >99.9% of the time. This is > partially why good MP3 can be VERY hard to detect... > > > 3) The sound simply does not collapse into a catastrophically dynamic > range limited, noisy mess if the digital volume is not at 100. You have > to go way lower than that... Final thought. You are listening to a > track. It starts to fade out. Does the sound quality collapse or does > it just get quieter. You know how that fade was achieved? ...yes you've > guessed... > > > 4) I don't care if my DAC can only resolve to 20-bits since the best > ADC's in the world struggle to get 20-bits of usable signal. The bottom > 4 bits are always just noise...
RE: 1) Your trying find the LIMIT of your DAC, not your ear or what you can hear normally. It's useful to know that limit. It's useful to prove your point in #4 to yourself. It also helps verify you system is truely passing 24bit to the DAC. And in one system where I thought I was, I'm not. RE: 2) Correct, the 4 most least signifcant bits are in audible. So why shift higher (audible) bits into the least significant bits that are inaudible and cannot be even amplified back if your DAC can't resolve that low. RE: 3) Don't assume attenuation is only achieved shifting things down digitally. You can have soft full scale data. Read up on Compression and Expansion. Even if Fading is done purely by digital amplitude why would you want to operate always "Faded" (attenuated digitally). RE: 4) I agree with #4. Folks keep saying "but it's 24-Bit Volume" so you won't lose anything audible (that's the mistake). NO, it's more like 20-Bit Volume (or less) and you will hear a difference. Because your DAC really runs at 20Bit-ish (at BEST with your EAR plastered to driver at full volume) and the extra 4 bits in 24bit volume are completely useless. That's why I did the test to see what the limit of the DAC is (in the best case). If the DAC came out 24bits that means with enough amplication you can get those real low level bits that were attenuated back into audible range. But if your DAC is really 20bit's then what your shifting out IS audible and can't be recovered (even by amplifying). -- mswlogo XP > Cat5 > Transporter/DuetController > SPDIF > Meridian G68 > DSP6000, DSP5500HC, DSP5000 XP > Cat5 > SB3 > SPDIF > Meridian DSP5000 XP > Cat5 > DuetReceiver > SPDIF > Meridian G91 > DSP5000 'My Transporter Setup' (http://forums.slimdevices.com/showpost.php?p=350741&postcount=45) 'Hitch Hikers Guide to Meridian' (http://www.meridianunplugged.com) ------------------------------------------------------------------------ mswlogo's Profile: http://forums.slimdevices.com/member.php?userid=9090 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
