Sound Out the Wrong Pipes

[sechs]

I was resetting up my computer, but couldn't remember how I'd attached my second set of speakers. Although most of the time I listen to stereo material and have my soundcard duplicate the audio to all of the speakers, I like to be able to pretend that I have surround when I have such material. So, I attach them to "rear" for later testing.

Later, I test with PowerDVD and AC3filter to determine that the rear channels (surround left and right) are actually being pushed out the soundcard calls the center/wide channels. No sweat, I'll just hook the speakers up to the "C/W" connector.

Yesterday, I got the idea that I could upmix my music to quad, and avoid having to turn the appropriate option on and off in the control panel. However, every plugin that I've tried sends the rear channels to what the soundcard calls "rear," and not to center/wide.

Anybody have any idea what's going on here, and, better yet, how to get everyone to agree on where the rear channels should go?

 

[ddrueding]

Which soundcard?

 

[sechs]

I have a Prodigy 7.1lt, which is based on the Via Envy chip.

 

[ddrueding]

Interesting. The system I'm working on has the xPlosion 7.1 in it, which I believe uses the same chip. I'll do some playing and see if I have the same problem.

What player/plugin do you use?

 

[Mercutio]

No. The Envy is totally different from the xPlosion (which uses a C-Media chip).

The Envy driver package includes some jack-sensing software that IIRC allows you to reassign which plug goes to which hardware function. Don't you have that installed?

 

[ddrueding]

Oh, ok...sorry, can't help you.

 

[sechs]

The Prodigy doesn't appear to use the reference drivers. This may have something to do with it using a special connector and pigtail for everything except for headphone and mic.

 

[Mercutio]

So basically, AC3-encoded material (guessing you're playing AC3-encoded stuff in both) is going out your center channel, but nothing is going out your rear channel in that case?

And Wave sounds are being played "right" with rear channel stuff going out the rear channels?

If you switch your Windows speaker setting to some other setting (6 channels, perhaps?) or your PowerDVD speaker setting, does that accomplish anything?

I'm wondering if you set PDVD to use 6 speakers, but Windows to 4 speakers, will it remix the center back to left/right stereo? I rather doubt it, but playing with the various speaker controls sounds like a vaguely productive way to start.

I guess you could always move to an external AV receiver and proper speakers.

 

[sechs]

Setting PowerDVD to six speakers sends sounds to all three sets of speakers (front, rear, and C/W). It's not clear to me that the rear audio is being routed to the rear channels in that setup.

The AC3filter has a matrix which basically allows you to manually remix the source channels into the output channels. If I force the rear input into the center or LFE outputs, I get no sound. If I force it to surround left and/or right, sound comes out of the C/W channels.

 

[sechs]

This situation may be unraveling...

I broke down and got out the manual today for the soundcard. In the very back, there is a table noting how the channels are "numbered" in the drivers. Lo and behold, 1 and 2 are front left and right, 3 and 4 are center/woofer, and 5 and 6 are surround left and right. Obviously, somewhere, the drivers let Windows know how it maps this, and PowerDVD and AC3filter were not catching on.

Flipping through the manual also reminded me that the card installs two drivers: one with the regular hardware interface to the card and another with a Qsound-based software interface. Qsound is there basically for post-processing and game 3D emulation (EAX, A3D, etc.); and, except for some experimentation when I got the card, I've never used it. However, it has a system for upmixing stereo material, which is, of course, what I'm kind of after here.

Now, I'm not really excited about this function, as Qsound does more than just mirror the front to the rear. It bleeds the two channels a bit and adds a delay before sending to the back; this is particularly noticeable on some mono Beatles material to which I was listening, where I would expect nearly the exact same sound to be coming from all of the speakers. As I discovered in accidental testing, the Qsound driver, however, has the after-effect of assigning the channels in the way that PowerDVD and AC3filter expect. So, I can get the rear channels out of the rear speakers.

Any theories on why PowerDVD and AC3filter don't seem to have gotten the channel assignment memo? I can't complain so much about AC3filter, being free software, but PowerDVD should do better.

 

[Mercutio]

I rather strongly suspect Cyberlink will tell you it's a problem with your hardware. On the other hand, Cyberlink's tech support has been very helpful the couple times I e-mailed them.

Six channel surround doesn't seem to be implemented very well on a lot of hardware. The jacks for Surround and Center/Sub don't even have standardized colors.

Anyway... mostly the way stereo upmixing to 5.1 works is to simply echo the left/right channels on the surround speakers with some tiny delay. Better upmixing processes like ProLogic II, DTS:Neo6 and Dolby Digital Live actually widen the stereo signal then break the components down so that each speaker has a discrete signal. ProLogic II support is a standard on current Intel motherboards and many nVidia-based boards, while a lot of nicer equipment (Gigabyte's $250 Conroe-capable board, for instance) is coming out with proper support for Dolby Live.

My point is, you may not get something you like from your current hardware in every program, but the next thing you buy will probably support one or more of the surround audio standards that should ease exactly the sort of confusion you're facing.

 

[sechs]

I suspect that the issue lies with the drivers somewhere; Qsound is third-party software that the manufacturer licenses. It's unfortunate, as this card has every feature that I want.

Hopefully, by the time I make my next upgrade, motherboard audio will advance to the point that I won't feel the need to have a discrete solution.