I'm trying to get surround sound working on my HTPC and having a horrible time with it. I'm using an Asus M2NPV-VM motherboard with NForce 430 (using the snd_hda_intel drivers) and 5.1 speakers that work just great on WinXP dualboot. Linux is being a pain and I'm having a horrible time debugging the problem.

I'm wondering if there's any utility out there to help test if 5.1 surround sound is working under Linux, perhaps to try to send output to each of the 6 speakers?

I notice my /usr/share/sounds/alsa directory contains:

Front_Center.wav Front_Right.wav Rear_Center.wav Rear_Right.wav Side_Right.wav
Front_Left.wav Noise.wav Rear_Left.wav Side_Left.wav

which makes me suspect I already have some testing capability, but these files show up as 1 channel audio.

Any ideas? Thanks in advance!

Using those wave files, audacity, multimux from Panteltje, and ffmpeg, I created a 5.1 Surround Sound test.

surround51test.ac3 (474 KB)

To play the file, type 'mplayer -channels 6 surround51test.ac3'.

To play the file infinite times, type 'mplayer -loop 0 -channels 6 surround51test.ac3'. Hit CTL+C to terminate or stop mplayer.

Since the subwoofer (LFE) channel has a very narrow frequency range, I used the noise file and put it through a lowpass filter by setting the cut-off frequency at 200 Hz. I also amplified this file by about 12 dB, so be careful with your volume or else you may damage your subwoofer. Several subwoofers in stores do not have what it take to actually produce good bass. I am thinking of just using the original loudness of the noise file. Only DIY subwoofers can only handle bass.

Sure, you could use speaker-test but it does not work for all sound cards. Also you could of used either DVD movies with speaker tests or a home theater test CD/DVD.

The only problem you will have is taming your sound card in Linux to output more than two channels because each manufacture uses different ways to handle nForce4 audio. I recommend using a separate sound card like Audiotrak Prodigy 7.1, Audiotrak Prodigy 7.1 HiFi, Terratec Aereon Space 7.1, M-Audio Revolution 7.1.

BTW, You may have to specify surround51 as your ALSA device when outputting to six channels on some sound cards.

Weird. I've managed to upgrade to alsa-1.0.14rc2. If I try to use mplayer on this file, it doesn't advance the file, just sitting at 0.0s.

However if I play it with 2 channels, it's fine. Same for 3, or 4, but for 5 or 6, it just halts.

Thanks for this file, it will help me debug.

ALSA version 1.0.14rc2 is still a development release. Some people had problems with this release when using snd-hda, so downgrade to 1.0.13 for better support.

I recommend spend the money on a PCI sound card instead of using on-board sound. The easiest and cheapest sound card to setup is Turtle Beach Santa Cruz (OEM). The sound cards that has best audio quality and still be easy to configure is Audiotrak Prodigy 7.1, Audiotrak Prodigy 7.1LT, Audiotrak Prodigy HiFi, Terratec Aereon Space 7.1, or any M-Audio sound card that outputs more than 6 channels.

If you still want to use your on-board sound card and you are using snd-hda, include the model option when it loads up.

I'll try downgrading to 1.0.13, now that I know how to properly upgrade.

That sound card is about 75% the cost of my motherboard! I'm willing to throw a bit of cash on this to make it go away, but at that price I'd rather tinker more or just give up and go with XP.

How do I specify the model option?