Power Amplifier Bridge Question?

[chris89]

So, I have this Tang Band 6x9 subwoofer I bought from parts-express.com and it's 90W rms @ 6.5ohm. I have this rca amplifier that's 2 channgels at 75W RMS per channel. So i bridged it from right channel positive to left channel negative. Supposedly that's the correct way to wire it up. However I have buzzing from the sub when the car is running and it goes away when i unplug the RCA's from the amp. So I bought a ground loop isolator and it doesn't work. So the tech said I need to bridge right channel negative to left channel positive with a small wire to get the full power from the amp. Anyone ever heard of that? He also suspected that once I do that, the ground loop isolator will work. The loop isolator works on the IP-BUS to rca's aux output that I have converted to 3.5mm stereo. However since the sub is in bridge mode and not sitting on channel 1 left right positive negative, it doesn't make any sound with the isolator. I don't get that? Any audio electrical guru's out there. I'm all yours brotha!

LATER BROS!!

[John C]

Just a dumb question, but you are sure that the amp is designed to be bridged? You cant bridge just any amp, it must be designed for it. If it is not, it will likely explode in short order.

[chris89]

Yeah, it was in the directions on the many ways to use the amp. It may be cheap but it works pretty good. This tech guy told me to bridge the empty terminals together with a wire to get the max potential of the amp to the sub. That's what I thought bridging did? He explained that because it's bridge is why the STEREO rca ground loop isolator doesn't work. I'm getting a ton of buzz when the car is running through the amp. When the car is off it sounds fine. Also, when I unplug the rca's to the amp, the buzzing stops...

THANKS