Amp as Sub

[catacon]

I have a bass amp in my room and I was wanting to use it as a sub for the computer to complete my surround sound. On my sound card, I have Front Out, Rear Out, and Center/Sub Out. I am using a 1/8" to guitar plug(?) adapter to connect the 1/8" stereo cable from the computer to the amp. My problem is thus: When the amp is in the Rear Out port, it plays the treble, that makes sense. However, when I put it into the Sub/Center out it doesn't do anything. I found, though, when I plug the cable about half way into the R-Out port in works (little scratchy). So what is going on? I tried a stereo to mono adapter to the R-Out port, but that didn't work. Any ideas?

Thanks!

EDIT: I am using a Mad Dog 5.1 card.

[catacon]

Anybody? I was think maybe it was because I was using a stereo cable.

[MaxRat]

you have to set your setting to reflect the hook up.... go into the sound properties and make sure you have all channels turned on....some boards you have to enable 6 channel sound...other do it via jumpers on the board...mine works fine but i have to enable it as 6-channel in the sound properties

[catacon]

I have done that. I have an actual computer sub that I will try. I'll post back after I try that.

[catacon]

OK, I got it to work. I went stereo from the computer to a mono adapter to the guitar plug then into the amp. However, there is a massive buzzing noise from amp. Any way I can fix that?

EDIT: I just realized, that wehn I move the plug away from the computer, the buzzing goes away. As I move it closer, the buzzing starts. My network card is right by the sound card, could that be the problem?

[SonicVanguard]

That massive buzz is either a ground loop (60Hz hum) which means there isn't a common ground between the electrical equipment or something not grounded right -or- it's a you've got an impedence issue - the soundcard's output is too high/low for the expected impedence of the amp.

[catacon]

Any way to fix this?

[SonicVanguard]

Originally Posted by catacon Any way to fix this?

Sure, don't use an amp intended to be used for a musical insturment with a system designed to playback amplified music.

[catacon]

All right then.

Thanks anyway.

[SonicVanguard]

Originally Posted by catacon All right then. Thanks anyway.

Well...You asked. I'm not meaning to be a spoil-sport, but you're sending a pre-amp signal (-3dBv) to a amp expecting a instrument level signal (either +4dBu or -10dBv). There's your impedence matching issue - if there's a ground loop as well, it could be any number of things (faulty/incorrect wiring 'someplace', improper ground fault in the amp, computer power supply problem...). You're best bet - and best way o fix the problem - is to use a speaker intended for the job.

[catacon]

Yeah, right now I am using a computer sub from another computer that I thought wasn't working. Now that it is I probably should return it.

Thanks for the lesson in sound, though.