Select multiple mono format to bounce stereo mix?

[el biciclista]

I have a ProTools HD 2 system on a Mac G4 867, running OS 9.2.
I am ready to bounce my stereo mix to disk, in preparation for burning a CD.

The session is at 96k, 24-bit. I plan to bounce in two steps, to avoid truncation from 24-bit to 16-bit:

Step 1 - Bounce to 44.1k, 24-bit, WAV file.
Step 2 - Import the file from step 1 into a new session. Bounce to 44.1k, 16-bit, AIFF file.

Then, I would burn the CD from the AIFF file.

In step 2 I know I need to select interleaved stereo as the format. However, what format do I select in step 1, so that I can end up with the stereo file in the new session? I assume it should be multiple mono, since the other two options (Mono-summed, and Interleaved) don't make sense. But I am just checking, to be sure Multiple Mono will in fact result in the stereo file I want.

Why the Multiple Mono option, but no Stereo option? Equivalent formats?

Thanks!
Mike

[el biciclista]

Anybody???

[dBgogogo]

Selecting the Multiple Mono option will create two files, a L and a R. When you import both of those into the new session, they will link.

[Doug Ring]

Pro tools works with multiple mono (split stereo) files, so assuming you're bouncing down to a stereo file from several tracks and want to keep you first bounce "inside" Pro Tools, bounce it as multiple mono. Then it'll appear as "Bounce.L" and "Bounce.R" and you can put it on a stereo track and play it back or export it from PT.

If you bounce to stereo interleaved instead, Pro Tools will have to undo the interleaving and create split stereo files before you can put the bounce back into a project to do the second bounce: that's an unnecessary processing step and so I would avoid it.

By the way, the second step is better as an Export rather than a bounce for the same reason as above. Just export your first bounce file as AIFF, Interleaved Stereo, 16 bit, 44.1kHz and it'll be ready for CD burning.

[el biciclista]

Doug,
I am doing processing in both steps:
Step 1 - Sample rate converting (96k to 44.1 k)
Step 2 - Dithering to 16-bits, WAV format to AIFF, multiple mono to interleaved stereo

Can I "export" when I am processing like this? I always thought exporting meant sending the file "as-is" to another location/session. I didn't realize I could process when "exporting" (versus bouncing). I guess I don't really understand the difference between exporting and bouncing.

Any further help would be appreciated!!
Mike

[frenchman]

If a file is meant only to be re-imported into pro tools, then dual mono is the right thing.

BTW, be careful with the resampling process if the mix has been maximized, as this process can (and often will)generate some peaks over the reference level

[Doug Ring]

Mike, bouncing is, as you know, real-time and is the means by which you combine several tracks into a stereo file. It's a bit like mixing your 2" 24 track tape down to a stereo tape machine. If you don't change any of the options that can be set before you bounce, you'll end up with a split-stereo file (Bounce.L and Bounce.R) in the same format as your session: 96k, 24-bit in your case.

But you can change lots of options before you bounce and have conversion to other formats going on while you bounce. So you could do a single bounce in real time that converts all your parameters and end up with a 16-bit 44k stereo interleaved file ready for CD burning which you can have Pro Tools put in any folder that you specify. Or you can do as you've decided and change only the sample rate first time round. If you do that, you don't want a Stereo interleaved bounced file because then you won't be able to put it straight into a Pro tools session - it'll have to put it back into split stereo format first. And in fact, you won't be able to import it back and play it in your master session anyway, because you can't mix sample rates in sessions.

So you would create a new session with the correct sample and bit rates and import your bounce into that. Now the minute you have a single file, mono or stereo, that is a finished product, you can export it. Exporting is faster than real time and allows you to alter all the parameters of the file. You can even make it MP3 if you have the optional software. Your computer just goes off and makes a copy of the file, number-crunching as it goes. So the second stage of your process could be an Export rather than a Bounce. I think, however, that dither is not applied during an Export - it's only a real-time process. You'll have to decide where to apply the dither and read up on the truncating process if that's what you want to avoid. You can still do a second bounce if you want to,though, and if you choose to bounce as stereo interleaved, you'll have a CD-ready file.

Hope this helps.