Hey all, I just put a system in my friends '01 extended cab Chevy truck.

He has Infinity components in the front doors and 2 Xtant subs under the back seat...anyway he kept the stock deck so we have speaker level inputs ( ) to the Kicker amp that runs the door speakers. then RCA outs of the Kicker to the sub amp.

my question is...I know you shouldnt let the RCA's get near your power cords because they will pick up alternator noise, but what else could be picking it up?

The crossovers are actually in the back by the amps and stuff (because we couldnt find a good place to put them in the doors)...so I was thinking they are too close to the power distribution block and the power cords. I havent had time to tweek on it, I will tomorrow, just wondering what I should look for (other than to move the crossovers). thanks

 

If you have engine noise, it's not coming out of the sub, so it's probably not the RCA's. If it were the tweeter xovers picking up noise from the power wires, it would happen whether the radio is on or off.

But the biggest suspect is the speaker-level in...this has been problematic for mids/highs for years. Try plugging a discman or ipod into the kicker amp and trying the RCA in (with the HU signal unplugged). If you have NO noise in that test, and I suspect you won't, you probably need to NOT use the lower-quality stepdown in the amp and use a better-quality stepdown - I would use an AudioLink or the AAMP branded version of the same thing. Ron might have one he likes too... but the one in the amp usuall isn't that good at noise rejection. THe Audio Link will probably sound better too.

 

Ya its not coming out of the subs...weird thing is, when I take the RCA's off the Main amp (ones to the subs) the noise gets worse (out of the door speakers).

So you are saying use a LOC to convert the speaker level signal to RCA? We were going to do this, but were going to see if we could save the $30 or so and not buy the LOC - but we will if you think that will get rid of the noise.

Also, you dont think its an issue for the crossovers to be near the distribution block?

 

I agree 100% with that. I actually use the Audiolink most often. No problems with it so far, been using it for about 3 years now.

 

About 8 years ago Soundlink came out with a "high-end" LOC that was supposed to have dramatically little phase shift.

We tested it on a PCrta next to an AudioLink. The AudioLink had dramatically better phase performance than the Soundgate, even though it has transformers and the SG had only a complicated resistor array (much cheaper to make, but in this case not as effective!)

 

so is the AudioLink an LOC or some other noise rejector that still uses high level inputs to the amp? And where can I get it? Also, what about the crossover placement next to power wires (will they pick up any noise)? thanks again!

I know alot about this stuff, but there is no substitute to real world experience (something that you guys have).

 

The coils in the xovers CAN pick up noise from power wires, but they will do it REGARDLESS of the amp being on or off. If there's no noise with the head unit/amp off, they ain't doing it.

The Audiolink is an outboard LOC that is better than what's built into an amp. Another think you MIGHT have to do is grab the ground wire off of the deck and ground it with the amp (and perhaps ground the AudioLink wire, but it's never helped me any...)

http://www.crutchfield.com/S-6pQbvC3...arch=audiolink

http://www.cardomain.com/item/STISALOC

Car Domain sells the Stinger branded version... same thing inside.

 

Well that was it for sure, we got a LOC and the noise is all gone - thanks for the help!

 

mine whines from outside the car, used to whine from inside, but that was a long time ago