Speaker problems

[locke2007]

Hopefully someone here may be able to help me, I'm currently in the middle of building my Mame cabinet but have run into issues with sound. my intended plan was to use a PC 2.1 speaker set (14 Watt output) to drive two 5" speakers (3W each), having clipped the exisiting speakers from 2.1 set and attached new 5" speakers to the cable everything works fine ran through my iPhone but as soon as I attached it to the PC i'm using the speakers keep making a continuous buzzing noise and then they seem to have blown the soundcard. Has anyone else come across this before or would be able to give me a clue where I am going wrong??

Any help would be greatly appreciated.

[MonMotha]

You have a ground loop.  Are you using the power supply that came with the speaker set?

[Blanka]

Oops

[locke2007]

Hi MonMotha,

The speakers I am using are these Sumvision Genesis 2.1 (cheap PC speakers more than enough), I removed the satelites and replaced the speakers with the ones I have mounted within my cab (These).  The sub from the speaker set is wired into a mains socket with the leads that came with it.

Hope this info helps.

[MonMotha]

So you did not alter the power wiring in any way?  Did you respect hot/neutral when you wired things up (sounds like you clipped the end off, maybe)?

On a different topic, are the new speakers the same rating (8ohm/4ohm) as the old ones?  Seems odd that you'd have no problems with your ipod then get this behavior when using a PC (again, seems more like a ground loop), but who knows.

[locke2007]

Hi guys,

Thanks for the feedback.

So you did not alter the power wiring in any way?

Nope, left the power wiring exactly as I found it.  Just plugged it into a 4 gang power strip.

On a different topic, are the new speakers the same rating (8ohm/4ohm) as the old ones?

To be totally honest this is all kinda new to me so I'm not sure what the old ones were, they were snipped off and slung away.

I have tried a different set of speakers from an old creative soundworks 4.1 set that was laying about, tried using one of the sattelites from that set and that also produced the buzzing noise.  So I think that there may actually be something wrong with the sub.  I'm going to try the creative set and if that works install that in my cab as it seems the subwoofer could be faulty.

[locke2007]

Final update.

Everything is now working ok.  The problem was indeed a ground loop.  Attached a ground loop isolator to the input of my speakers and now with a replacement soundcard everything works fine

I'll post pics and details of my cabinet at a later date.  Only thing that is left to do now is artwork