I've painstakingly installed my Soundstream amp in the trunk (on top of the tool box cover). I have 4 ga power and ground; all properly installed with the help of an ex-installer. The RCAs and speaker wires are run away from the power wire. The RCAs are quite high quality, as are the speaker runs. Unfortunately, I think I have a bad ground... I have engine noise, especially when accessories are on (A/C, lights, use the power windows, use the power mirrors, etc.), so I'm looking for suggestions on an alternative ground location (without drilling into the car, if possible). I am currently grounding the amp to the unused factory 10mm thread that's in-between the taillights, under the trim. I've also tried grounding to the thing that looks like an anti-sway bar that's under the spare tire. Any other suggestions for good ground locations??? Oh, and yes, I have filed-away all the paint where I've tried grounding. THANKS!!!

 

hrm. i used the bolt mounts that you referred to...
as you can see here from an earlier install i had. i still use the same ground on my current install w/ 4-gauge.

if you're still getting noise, have you tried verifying that you have a good ground on the head unit?

you'll need to try and isolate the noise. try disconnecting the RCA's from the amp and see if the noise is still present. if so, then your problem is the amps. if not, then it's your headunit and/or RCA's.
does the noise get louder as you change volume? or is it essentially the same regardless of your volume setting?

 

I am simply using the spare tire screw thingy - that holds it in place. Unscrew it, stick the ground wire terminal in between the spare & the screw & and put the screw back in tightly. I've checked with a multimeter and it's a good ground.

The grounds you've tried are what most people are using so I don't see this as your problem.

 

I used the stock Honda ground and not ground noise at all.