Tao Zervas wrote on Thu, 25 August 2005 14:39 |
Hello,
I recently had an unpleasant surprise when I tried to bounce some mixes internally in Digital Performer, as the sound quality of the final mixed track was much inferior to the seperate tracks on playback.
Tao
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Tao, can you explain this as clearly as possible. Are you saying that the same MIXER in performer that "sounds good" to you when playing back does not produce the same file quality when used in a bounce or capture?
I have done OBJECTIVE testing on bounced files done in various ways from Pro Tools. Clients have sent me digital mix bounces done in three ways:
1) by capturing directly in the Playlist
2) the bounce to disc dialogue that makes a separate file
3) Capturing digitally via SPDIF or AES to an external device (e.g. Masterlink) or another pro tools system.
And (assuming the Pro Tools system is working properly and not defective or pushing the CPU to the limit) ALL THREE FILES test IDENTICAL, bit for bit. Needless to say, there is no sonic difference either among the bit-identical files.
The ONLY differences I have been able to quantify between "btd" versus capturing the output digitally in the EDL or Playlist or an external device have been when the CPU has been underpowered, and the automation has not quite caught up or matched between the two different types of "bounces". I had a client with Cubase and an underpowered PC where bounce to disc really sounded discrepant (and measured differently!) to capturing a "live mix" in a Masterlink. There are logical reasons for these different methods sounding different, but we have to separate the voodoo from the facts.
The fact is that technically, there is no difference when a mix engine captures its output "offline" to a new file versus to a pair of tracks in the EDL. If there IS a difference and you can quantify it, then you have a defective system. Defective by definition. Stop looking under rocks for worms and look for the real physical reasons if you find defects where there should be none. And finally, prove to yourself that your captured files are truly not-identical. It is so easy for the mind to think that two sources are different when they are identical. It is much harder to admit that two sources are identical when they are.
The other day I did a comparison between two D/A converters, and for technical reasons I don't need to get into here, I was forced to play two copies of the same CD through two different transports into those D/As. UNTIL I was able to synchronize the two CDs by trial and error so that there was no delay when switching, I reached erroneous conclusions that one sounded better than the other. But it was simply that I was listening to two different parts of the music. If the delay is less than a second and more than a few milliseconds, the brain goes into overload and really reaches wrong conclusions!
BK