Confusion, thought i had this right!

[75MonteCarlo 10+ year member]

Ok, i've been working on my own system for quite a while now, posting on here, lurking, reading, learning, and i thought I had a pretty good idea of what i'm doing, but I guess not. See if you can figure out what my problem is here:

I'm getting alternator whine and signal noise through my speakers. The speakers are distorting at lower volume than normal, and doing so in tone with the bass beats.

I've got a 2nd battery in the trunk, as a way of grounding all of my electronics directly to the battery to eliminate noise. My rockford amp along with 2 caps and my speakers amp are all grounded and powered off of the rear battery directly. The ground point on my battery is grounded to the frame and the ground point has had the paint ground off so that it was shiny metal to ensure good contact.

I ran 2 seperate pairs of RCA's from the deck. The sub pair on the power wire side of the car, the Speaker amp pair on the other side of the car, away from power wires. When connected, I had bad signal noise. This was before the addition of the second battery. After putting in my 2nd battery, I then used the pair of RCA's that are run away from power wires to feed signal to my sub amp, and used the pass-thru on my sub amp to connect RCA's to my speaker amp. Are you with me here?

RCA's go Deck--->Rockford T10001bd--->Clarion 2-channel speaker amp.

Power goes: Front batt--->rear batt--->0.5 farad cap--->1farad cap--->Rockford T10001bd

The clarion is powered from the rear battery seperately from the rockford. (not connected to the capacitors)

My experience has been that when I use seperate RCA's on each amp I get bad signal noise, but when I use the pass-thru from the rockford the signal noise isn't as loud.

Seeing as everything is grounded to the battery, would it be better to ground the Sub Amp and caps to the chassis, and ground the Clarion speaker amp on its own on the battery?

**** I can't seem to put this into words that make sense.. anyhow I hope this is legible, maybe someone will see the problem. Ground issue? bad amp? bad deck?//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

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[VereChronicus 10+ year member]

Quick way to test if you have a problem in your signal cables: take the head unit out of the dash and disconnect RCAs from amp and head unit. Use a spare set of RCAs just run over the seats and to your amp and head unit. Obviously, if the noise goes away, it's in your signal cables. If not, time to start hunting deeper. First off, always ground your caps to chassis, all diagrams for those show chassis-direct short ground cables. Test your voltage at the amplifier under your normal listening (and symptom producing) volume levels. If it's dipping below 12V with caps and a 2nd battery, your alternator is taking a fat sh*t on you. Be happy to know, though, that it's waiting until you are the furthest from civilization to completely crap out. Alternators, after diodes and such pinch a loaf, tend to generate noise. Check those things foyst and get back to us wiff your findings.

 

[75MonteCarlo 10+ year member]

The whine is there no matter what volume, its a constant nosie, that only goes away if I drown it out with music. Now the speakers are distorting majorly at anything over normal listening levels, and my subs sound distorted, even though i've got the gains down.. I should never have tried wiring them down to 1 ohm.. everything was working fine at 2ohm.

 

[zachzchw 5,000+ posts]

Rewire them back to 2 ohms, if you havent already tried that. Did you set your gains properly?

 

[VereChronicus 10+ year member]

You should still do a load test on your alternator. Take it off and test it at a local Auto Zone or similar auto parts store. Sounds like one of two possibilities: 1) alternator is dying or 2) Amplifier pinched a loaf on you after you dropped the impedance. Check to see if the amplifier still makes the noise if you disconnect the RCAs at the amp.

 

[75MonteCarlo 10+ year member]

If I disconnect at the amp? If I disconnect my RCA's there won't be any sound at all. And it did this before, when it was wired @ 2 ohm.