I've gotta a major ICE install with all correct cabling etc routed correctly. However Iam picking up some minor alternator noise through the system. I have tried an 'autoleads' suppressor which eliminates this buts ruins the quality. Any ideas?

 

First off, are you sure its alternator noise? Is it RPM dependent?

I had bad noise induced in my passive x-over when in the driver's footwell that was RPM dependent... Solution was to move the x-over.

A coil of RCA cable acts as an arial. If your cables are running under the rear seat, watch out for the fuel pump wires - had that before, too.

Another potential is a fugged RCA cable. Happened on a kenwood lead I had - the insulation became disconnected. Truly horrible, and sounded like alternator noise.

Final thought is in grounding. How have you grounded your amp(s)? Are the amps themselves mounted onto metal? If so, try isolating them.

 

Thanks for the reply. Yes it is RPM dependent. All amps are grounded to the same point and are mounted on wood. There are no coils of cable. There is a single power lead (2 gauge) to boot and then distributed. RCA's are all phoenix gold handmade. A friend mentioned that you could put a capacitor on the alternator to stop noise.

 

Time to start playing then

Try removing the RCAs from the amp. If you still get noise, it's from the amp onwards...

Likewise at the head unit...

Sounds like I'm preaching to the converted here, so sorry for that.

I can't think of a shortcut other than to start playing with disconnecting things. Yuk.

 

Thanks for the advice. Iam running a Rockford EPX2 active crossover and 28 band EQ so it all gets v complicated and does my head in. I was looking for a short cut. Any further ideas appreciated

 

Give me the EPX?

Perhaps one of our resident sound engineers has a clue?

Are you grounding your RCA shields? It may be worth trying that...

 

Hey Chiark - you call, I answer ;-)

Sorry Silver Surfer, but I'm with CHiark on this one - fault finding a system is a pain in the **** :-( but I find the easiest way is to draw the system on paper first. Sorry if it sounds stoopid, but it's either that or as Chiark sez - pull out ALL your RCAs and start pluggin 'em in one by one.......

There is another item you can fit into the chain, but the name escapes me at the moment - I'll do some searching at work tomorrow and re-post.....


Dan :-)

 

Thanks for the responses. I know trial & error is the way to go. I use Phoenix gold RCA's (handmade) and the plugs are so damn tight that I did have a problem where they pulled the RCA socket off the EPX when removed. The system is fairly simple: single RCA from Alpine 7619 (old but good) to EPX 2. Then all RCA's go to amps (Genesis 240, 4 channel) for front dynaudio 6 1/2's and tweeters. Rear is JL 10w6 off a Punch 200. System runs a stiffening cap, and one of those jelly type batteries.