Wav merging, file size reduction: How to?


I record audio using a Fostex MR-8HD, it produces huge wav files. Ideally I would like to:
1- Merge the 4 channels into 1 file WHILE KEEPING the separete channels (Does wav or mp3 support this?). Helps me deal whith interruptions, I need to listen to what all the parties say when they interrupt eachother, this is the main reason for me to record using a multichannel equipment.
2- Reduce the file size of this new conbined file.
3- Break this file into aproximatelly 30 minutes segments.
How would you guys go about doing this?
I’m a real newbie in this. I know the recording equipment handles syncronisation in some way, that shouldn’t be a problem for the Audacity program to merge them right.

Thanks in advance and please excuse my English.

First, you have to use Audacity 1.3.3. The older versions don’t support multichannel output.

Unfortunately, Audacity yet doesn’t support multichannel playback, so you’ll have to use it strictly to make the wav file, but not to listen to it.

Second, wav does support an arbitrary number of channels. It’s probably the format you’ll want to use. But be aware that there is a 4 Gig file size limit for wavs. I don’t know what your definition of “huge” is, but that’s something you need to watch out for.

The method to do this is as follows:

  1. Import each track into Audacity separately.

  2. Don’t worry about panning them, but make sure they’re about the same volume level.

  3. Click Edit → Preferences → File Formats → select “Use Advanced Mixing Options”

3a) At this point, I would save the project as is, but it’ll be a huge bunch of files.

  1. Highlight the portion you want to export. Make sure you highlight all 4 tracks.

  2. Click File → Export Selection. Name the file and select the right output format. Click OK and you’ll be sent to a new window that lets you select the output channel for each track in Audacity. Send each one to it’s own channel. When you’re done, you’ll end up with a wav file with 4 channels, each containing one person speaking.

  3. Now, you can delete the part you highlighted and then highlight a new portion and export as above. This is why I said you should save the project, since it’s often easier to just delete what’s already been exported and continue like that. Just make sure you don’t save the project once you’ve started deleting pieces of it.

Normally I would tell you to use Export Multiple to split files, but Export Multiple doesn’t work with multichannel output (I don’t know why).

Thanks a lot, this will be very helpful to me.

Revisited: Hey, THANKS a lot again. You gave me the much needed pointers to start playing around. I’ve moved miles forward with this.