> >> does Logic automatically dither down from it's internal mixer's bit >>> depth >>> (32 bit float in this case) to 24 bit fixed > >very short answer ;-) >there really is no need to dither to 24 fixed. >dithering adds noise at level below lsb - with 24 bits this is so >microscopic as to be unnecessary. this seems wrong. Why would Logic do all internal processing at 32 bit to then just chop off the lowest 8 bits of information on output? Jules - I was told that Waves L2's dither only is applied when selecting a bit depth of *less* than 24. i.e. its not doing any dithering if you leave the bit depth at 24. I like you wish that a Logic developer / engineer would shed some light. I myself have wondered if digital mixers that use a 48 bit or greater mixing buss sound better than Logic's 32 bit mixing buss. What bit depth does ProTools HD do all of its mathematical calculations at? Comments? -devin

On Tuesday, February 3, 2004, at 10:09 AM, lists@... wrote: > this seems wrong. Why would Logic do all internal processing at 32 bit > to then just chop off the lowest 8 bits of information on output? because the processing itself involves truncation at every step. dithering also involves chopping off the lowest 8 bits on output - although the highest of those bits is "tracked" by the added triangular dither and the ear is capable of turning that tracking into a bit of info at the level of the one bit below the lsb. i know the dangers involved with saying that it doesn't make a difference - i.e. my ears could just be shot. however, a single slash down to 24 fixed from 32 float (which depending on the "float" may be more complicated than a slash anyway) is of a an order of quiet out of the range of any kind of biological hearing! the lsb of 16 bit is audible depending on your hearing. the lsb of 24 bit is not. i'm sure in the year 2030 there'll be someone who can "hear" a truncation to 1024 bit.... the question really isn't a "dither for sound quality" one. the whole idea of dither is to *introduce* noise to get distortion into a range that is inaudible (on average). the need for 32 to 24 dither undermines the working concept of 24 to 16 dither. i don't know if logic dithers when outputting in 24 bits but it is just a toss-up between to types of (genuinely) inaudible distortion. steve parker.