TerryS;613524 Wrote: > Claiming that 16 bits provides 96 dB of dynamic range ignores the fact > that the distortion rises as the number of bits decreases. For an > analog system, it is OK to define the dynamic range as the ratio of the > loudest signal that can be produced to the quietest (or the noise > floor). But I have a problem when they apply that same definition to a > sampled system. Sure 16 bits implies 96 dB: 20*log(2^16) = 96dB). But > that means you are willing to accept absurd amounts of distortion (100%) > as a reasonable "signal". The distortion (due to quantization error) > increases as the number of bits decreases. With 16 bits, the > distortion is very small (0.0015%), but each bit that is removed > doubles the distortion. So a signal sampled at 6dB lower than the peak > level will have double the distortion. How much distortion are you > willing to accept? If you draw the line at 1% distortion (pretty high > in my opinion), then that requires 7 bits. That means the dynamic > range of a 16 bit sampled system is only 54 dB: 20*log(2^(16-7))= 54dB > if you limit the distortion allowed to less than 1%. About as good an > old cassette deck. Not my definition of "Hi-Fi". 16 bits was a > compromise based on the available technology of the day. Many people > still claim it is good enough. Many others don't agree. > > Terry
Except it doesn't work like that in practice because we don't record at 16 bits or less, we record at 24 (OK let's call it an effective 21 in reality) and dither down to 16, effectively masking (decorrelating) the quantization distortion. Thus the effect of quantization error on low-level signals is nowhere near as bad as it would be if we were still (1980's) recording at 16 or even 14 bit! -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/XP) - Audiolense 3.3/2.0+INGUZ DRC - MF x-dacv3/x-10/x-psu(Audiocom full mods) - Linn 5103 - full Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters, Blue Jeans Belden Digital,Kimber 8TC Speaker & Chord Signature Plus Interconnect cables Stax4070+SRM7/II phones Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. ------------------------------------------------------------------------ Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=85879 _______________________________________________ discuss mailing list discuss@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/discuss
