I just installed some new 6X9 speakers to replace the factory ones in the back seat. I have a little 200W amp hooked up to them. The ground, power, and reciever hooked up to my other amp which goes to power subs. When I turn the speakers on there is a are loud medium frequency sound coming from them. Its really loud and cant be ignored so I have no idea what to do. TIA

Wait, you have your ground and power "hooked up to" another amp? Explain that.

You have a ground loop is what you have. I bet when you hit the gas the frequency goes up doesn't it?

Don't ever jump power or ground from one amp to another. Run a power block splitter and ground the amp to the body of the car, not back to another amp.

Ok, well I have my amp that powers the subs all hooked up right and it works just fine. So where the slot is for ground I just ran a wire from that amp to the little one. The same for the power, so there is only one wire going up to the battery. I take it that is the incorrect way to do it. How exactly should I proceed in getting rid of this frequency noise? And yes it does increase when i give it gas. Thanks for your advise so far, i'm sure it'll help!!

Well first of all that is the WRONG way to hook up an amp. Ground the amp to the body, not back to the other amp. Secondly put a power distribution block in front of your sub amp and run 2 power lines from it. One to the sub amp and the other to your 6x9 amp. Third make sure your RCA cables from your head unit aren't running parrallel with your power cables and definatly not touching anywhere. You should get triple shielded cables and get them long enough that you can run them through your car like a snake, not just in a straight line.

If you still have the noise you can pick up a ground loop isolator for VERY cheap. I had to do this with my mom's 4-runner a couple years back. Even after re-wiring everything.

Ground loop isolators are like bandaids. They cover the wound but don't cure it. Try everything you can before you resort to that.

"You have a ground loop is what you have"
-brought to you by the department of redundancy department. (lol, j/k aaron).


aaron is exactly right. ground the new amp to a clean, paint free mounting point...not to the other amp. right now, theres a massive resistance placed on the new amps ground, as it has to travel through all of the other amps "internals" to reach a ground point. because of this excessive load, the amp looks for other ways to ground, and it sees the signal ground as a good place. in doing so, it modulates the audio signal based on voltage changes in the ground (due to the minor, but important, voltage corrilation to the RPM).

on a side note, PLEASE make sure you fuse all power wires. "piggybacking" power wires is a bad idea.

:shhh: i do cocaine :/shhh:

Ok, so then do I need to run two separate wires (one from each amp) to the battery or is that what the distribution block will do?? And what size wiring should I use to for the new ground and power from the smaller amp. Is 8g to big?? Thanks!

Ok, well I actually have 8g wiring coming from my battery (only two memphis 10's with a 600w crossfire amp), so I have a distribution block with 4g in and dual 8g out. I got it for free so I was wondering if that will work if I just put the 8g in the 4g spot. I dont see why it wouldnt work. ALSO, where should I have the Rem go on the little amp????!!!! Can i just split the Rem wire going to the big amp and just add wiring in to the little amp or how should I go about connecting that all up??? Reminder there is no more spaces in the back of my deck to plug anything into. And is RCA the same thing as Rem???

Well, I did some research and people and shops all had mixed answers between a ground loop isolator or a splitter for the RCA's. I only have one pair of RCA outputs from my deck so I just have those into the bigger amp. Then I have the high output from little amp connected to the 6X9's. So what route should I go toward first? Ground loop isolator, RCA splitter, or another solution?? About how much do each of these cost? TIA