ok...well I thought I would post this here cause I assume this would get the most traffic for this problem...

In my '65....I have terrible interference in my speakers from my engine...gets louder and higher pitched with the raising RPM.. Its mostly (if not only) in my back speakers that are powred by my amp...Any ideas as to how I can fix this? Thanks!

 

New shielded spark plug wires will help.

 

Spark plug wires? This is a new problem...it just started doing this the other day...I've had the same plug wires for years...

 

Didn't realize this was a new problem, plug wires probably are not it then. It's could be a grounding issue with your amp. The amp and speakers should be shielded against outside interference, unless they are not wired properly or something.

 

so check the grounds?

 

anyone else have experience with audio troubleshooting??

 

How is your amplifier grounded? If it is bolted to just the chassis, that might not be sufficient.

 

I had that problem with my aftermarket stuff. And they put a noise filter in leading up to the amps.....

 

ok...I think I'm just going to go through everything and make sure I have good connections everywhere..clean everything too, Thanks!

 

this is commonly refered to as alternator feedback.

Causes:
- Bad ground (check the amp ground and the chasis ground)
- RCA wires too close to the power wire. ALWAYS run them down the oposite sides of the car.
- RCA input on the amp has blown.


Troubleshooting steps:
1. Check the ohm load on the negative wire on the battery. Also check the amp ground ohms. If all is fine, your grounds are fine.
2. Run a new set of RCAs. If it is still making noise your RCA's are fine. (make sure you run the new set AWAY from the power wires)
3. If the above do not fix the issue, then try borowing a cheap amp to replace yours. If the problem goes away, its your amp. If not, it might be the head unit outputs.

check those and let me know if doesnt go away. You can add a line filter to filter the noise, but its better to find the issue then to just mask over it.

 

and the winner is......

BAD GROUND!!!

or....too many grounds!! It appears that the bracket the amp is mounted to the floor with was grounding it already, and then the ground wire from the amp to the chassis was freaking it out...I took the ground wire completely off the amp...threw it in the trash....and the speakers stopped buzzing! Thanks Guys!! Time to install my new head unit!

 

Glad to help, and glad it works now!