Exporting Multitrack Surround Files in Audacity
Notes to myself!
Suppose you want to create a surround sound file using Audacity. The app is a little obtuse, so this may clear up some confusion.
When exporting, Audacity defaults to mixing down to stereo. You must adjust these settings: Edit → Preferences → Import/Export → Use Custom Mix
Lay out your audio. Keep each track as mono. You can have as many tracks as you like and then downmix them later.
File → Export
If you choose a surround compatible format, like .ogg, you will be able to assign each track (on the left) to an output channel on the right.
The channels don't have names - which is really unhelpful. Here's how they map according to the OGG Specification.
1 Left 2 Centre 3 Right 4 Surround Left 5 Surround Right
If you want to test it for yourself, here's a simple multitrack ogg.
Jordan Olling says:
How do I listen to a surround sound mix I've made? Supposing I could find someone else's home theater (I don't have surround sound at my home), how would I play the mix I've made on their surround sound system? Would I have to put it on a DVD? Can I play the .ogg file on my laptop (VLC Media Player) and connect the laptop to the home theater system with an HDMI cable?
Terence Eden says:
Hi Jordan, Playing through HDMI from your laptop should work. You'll need to tell your soundcard that it's a surround sound source - and possibly configure VLC. If you run something like kodi.tv, it will play multi-channel ogg files perfectly. If you want to burn it to a DVD, you will probably need to convert it to AC-3 or DTS first. Good luck! T
Mihael Glasner says:
DD 5.1 --- Thank you very much for this. I can confirm that this procedure works with AC3 (Dolby Digital) sound tracks as well, as long as you have the ffmpeg for Audacity installed - easy to do from Audacity itself. Difference: AC3 order is not the same as OGG - 1 Front Left, 2 Front Right, 3 Centre, 4 LFE, 5 Rear Left, 6 Rear Right. I had some videos in the MP4 container, with 6 ch sound. In order to play that on a Samsung TV (and get the audio from a Home Theater system), it is necessary to first change container (no recoding) to MKV (MKVToolNix GUI), extract audio track (gMKVextract GUI), open audio in Audacity, export as 6 ch AC3 - using the way you described, just with different track numbers and finally mux again with MKVToolnix GUI (MKV merge, but the GUI is simple and easy). AVC video will not suffer, there is no recoding involved, and Audacity converts the AAC LC used in MP4s without noticable loss. This might help someone else, as ogg is not supported by many standalone devices. Regards, Mihael
Jon wick says:
How do i import 6 channel audio so all elements are seperate tracks?
@edent says:
What format is your file? Audacity should just open it and allow you to select the tracks.