Car Stereos: car amp trouble, crazy glue, car amp

Question
I have an amp hooked up to 2 6x9's and 1 of the speaker pushes out the highs but no bass I have tested the speakers and they both work and both channels on the amp are functional what's weird is the original speaker wire in the car on the left works fine but the original speaker wire on the right only pushes out the highs. Is it possible that it's the head unit? Or should I just start from scratch with a whole new wire kit? And I also have a noise compressor but I'm still getting the "whining" noise. Could I hook up 2 noise compressors or would that not do anything? Your help will be greatly appreciated. Thank you for volunteering your time. You guys rock.

Answer
Hi Charles,

The first thing to check is your imaging.  Make sure the speaker isn't hooked up backwards.  This can cause your bass to go to hell and the sound not to come out right.

If that isn't it, then swap the inputs into the amp.  If the sound issue stays, then you can rule out the deck.

Then, swap the speaker wire coming out of the amp.  If the issue switches sides, then you know it's the amp.  If it doesn't, the only possibility remaining if you've swapped speakers already is the wiring to the speaker.

As for whining, those filters are a bandaid, and I try to avoid using them, since it means you have something else you need to fix.  It's like trying to repair a broken bone with crazy glue.

EMI comes from many sources.  The most common is a crappy ground.  Make sure your ground wire is as short as possible, at least as heavy a gauge as the power wire, and is connected securely to chassis ground, preferably unpainted, bare, clean metal.  If that doesn't fix it, make sure your signal wires are not running alongside any power wires.  If your amp is in the trunk, run the RCAs down one side of the car, and the power down another.

If that still doesn't do it, look into cleaning up/adding grounds to your car's electrical system.  Some cars are notorious for noisy/crappy grounds, and a few extra heavy gauge wires connecting major components and the chassis to the ground terminal on the battery helps for a cleaner path to ground.

Good luck,
Justin