Enabling 5.1 surround sound in OS X

Close to 18 months ago, when I first started seriously using that old mac laptop, I decided I needed a way to easily transfer my speakers between the desktop games machine and my mac that I used for everything else. One of my mates at work had an Audigy 2 NX, and after borrowing it for a day to make sure it worked on macs I decided to get one. It wasn’t until I had it that I realised the mac was only giving me 2 channels instead of 5.1 😦

I shrugged and chalked this up to the built-in mac drivers, it was fine under windows with the official creative drivers.

And so it was that when I upgraded to the mac mini, and again with this second mini, that I was stuck with a sound card that wasn’t giving me surround. Most of the time this doesn’t concern me as I usually only listen to stereo sources, but I’d never even considered that it might work (the few references I could find to this device on the net were it only working in stereo on the mac).

Until tonight.

While doing some research for a friend who was interested in USB sound cards, I saw a product review stating that the Zalman USB card does work on macs in full 5.1 surround mode. This piqued my interest so I went searching and stumbled on a list of working sound cards forum post. Right there at the top is the Zalman card, but hang on, what’s that sitting at the bottom under supported 7.1 cards? Why it’s my damn Audigy 2 NX! WTF!

I immediately (and stupidly) installed the package attached to that post, but thankfully I read a bit further down the post before rebooting and realised I didn’t need to. This was a good idea because the package is from 10.4 somewhere and I would almost certainly have been left trying to do a restore from backup. I’ve reverted the kext files that the package installed, hopefully my mac doesn’t die when I reboot it after posting this.

In any case, the answer is Audio MIDI Setup! A program that had always sat in the Utilities folder looking summarily useless but turns out to be the hidden gem that Apple really needs to make more obvious. For those who will no doubt arrive here from google one day, here’s how to enable 5.1 surround sound on a USB sound card:

1. Select your sound card under the Properties For: dropdown
2. Select the number of channels under the audio output format
3. Click Configure Speakers
4. Select Multichannel
5. Select the correct number of speakers from the dropdown (only the valid one should be enabled)
6. You can now assign channels to each speaker, I’m pretty sure the numbers I used are correct although 3/4 and 5/6 might be in the wrong order

Here’s a couple of screenshots with number highlights to make it clear:

Maybe it’s just this sound card, but that’s a ridiculous requirement to get 5.1 surround sound working (and I haven’t actually tested if DVDs will play correctly, only some 6 channel test wavs I found). Wish me luck! 😉

On the plus side, if this does work I will no longer have to worry about surround sound output from my media centre when I buy proper home theatre speakers (the audigy has optical and spdif out). I had been concerned that I would be stuck with stereo output from my Mac forever!