In Reply to: RE: Mastered for iTunes Critic Used Flawed Test to "Say BS" posted by tom.dennehy on March 15, 2012 at 08:54:16:
I agree with the suggestion to keep 32 bits for as long as possible. I had been in the practice of keeping intermediate files in 24 bits, but then a critical listener pointed out that portions of a file that I hadn't gotten to editing as yet did not sound as good as the original 24 bit file. I'd been removing clicks and pops and had already sunk several hours into a few minutes of a 30 minute recording and the portions that I'd fixed were obviously better, but I was shocked at the comment that the other portions sounded different. So I did a null test between the original file and the partially edited file, looking only at the end of the file that I hadn't gotten to yet. The file nulled out at -135 dB, i.e. all of the 24 bit samples were either identical or differed by +- 1 in the low order bit. This difference produced a different sound. Now I keep all of my master files at the highest available resolution, which is 32 bit floating point for most of my software. (This difference was caused by the edition of dither noise when converting from 32fp to 24int. Successive unnecessary conversions will add additional amounts of dither noise.)
Actually, 32 bit floating point is not good enough either for any serious processing such as equalization or sample rate conversion. At least 48 bits of working precision are needed and this means using 64 bit floating point in most computer systems. I suspect in a few years we will see workstations keeping files in 64 bits. One can't keep track of a million dollar bank balance down to the last cent if one uses 32 bit floating point. :-)
In the article you linked there is an incorrect reference. "The map is not the territory," was said by Alfred Korzybski, not Marshall McLuhan. Marshall McLuhan is famous for the phrase, "The medium is the message." With AAC or MP3 the medium is definitely the message, and the message isn't music. (Some say the same when it comes to 44/16 digital.)
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
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Follow Ups
- RE: Mastered for iTunes Critic Used Flawed Test to "Say BS" - Tony Lauck 11:23:50 03/15/12 (4)
- Good to see the (correct) Korzybski affirmation. NT - Poles Apart 18:31:40 03/18/12 (0)
- RE: Mastered for iTunes Critic Used Flawed Test to "Say BS" - tom.dennehy 11:34:03 03/15/12 (2)
- RE: Mastered for iTunes Critic Used Flawed Test to "Say BS" - Tony Lauck 11:54:46 03/15/12 (1)
- RE: Mastered for iTunes Critic Used Flawed Test to "Say BS" - tom.dennehy 17:28:47 03/15/12 (0)