Does any one know any other way of getting rid of this noise, I've grounded everything to single point and run power and sound seperately to the Amp?
I built the amp, crossover and bridging circuit which works fine till you start the car, which is a bit of a problem.

Jaycar 40 amp car noise filter, connects between the battery and the line to your amps...

I installed it and no noises any more :) and only costs bout $30

You have a whine in your woofer?!

What frequency is it crossed at?

i get horribly whine but only in my splits not my woofer. I will have to go over to jaycar during the week and get one of these noise filters...

Don't get those noise filters as they will reduce the sound quality, and it's really just masking the problem. Check whether your RCAS are within close proximity to either the ECU or SRS control box as they both give off EM radiation.

I ran my RCAS down the LH side console, across the front of the pass. seat, then up the side of the car, bypassing both of the above components. I don't get any alternator whine at all even during silent passages in tracks. It also helps though having a head unit that has 5V outputs. Also try a different ground point for the head unit.

Does any one know any other way of getting rid of this noise, I've grounded everything to single point and run power and sound seperately to the Amp?
I built the amp, crossover and bridging circuit which works fine till you start the car, which is a bit of a problem.


it sounds like u have done the wiring correctly, but is tha AMP itself actually properly shielded?

and i really dont suggest getting one of those noise filters if u plan on having a decent quality system as yes, they do reduce quality.

if u can't figure out how to fix it yourself, don't be afraid, send it to a car audio store, they're trained not to have these problems and they couldn't charge more than $100, it shouldn't take them longer than an hour or 2. and it would def. be 3 times better than a filter!

just a few suggestions for ya mate. good luck into noise free stereo! (well, unwanted noises anyway!)

oh and btw, don't bother with a cannon muffler as you'll end up rattling the rear vision mirror.... this is THE most annoying sound in the whole car, you'll hear it on every beat and pulse with every tone, and any noise the muffler makes and appears to be very common....

now how to fix mine...

:headbange :swearing: :headbange :swearing:

Thanks for the feedback, the amp doesn't have shielding which is a good point thanks.
The crossover is about 1000Hz but i'm going to reconfig to 500HZ, looking at the attenuation curve 1000HZ is where it starts to drop but it's closer to 2500Hz before there's significant attenuation.
I'm not sure how you guys come up with a power line noise filter affecting sound o/p as it wouldn't be in the sound amplification path so there shouldn't be any attenuation of waveform. Wouldn't it purely smooth and/or dissipate the ac ripple oo the dc rail and any spurious Voltages caused thru switching.

I have also changed the lead from head unit to amp to a Shielded twisted pair (1 shield and 2 hot wires) to try to eliminate ground loops and induced EMF, didn't do a damn thing.

Thanks again and please let me know any other ideas or flaws in my thinking as this is frustrating. By the way the set up isn't in a magna it's in Michaels car but please don't expel me I still have Magnas in my heart.

1000hz? u sure or do u mean 100hz?
My amp running my sub is on Low Pass Filter, and the cross over at about 150hz.

i cross my sub at 100hz! that's because my mid bass can't go below 100hz!
if u crossed it at a 1000hz then you will get music playing through it! not only bass!

Remember the subwoofer is deigned to fill out the bottom end sub bass region, in other words 100hz and down.

What the best sounding system do is this:

1. Using plenty of power the fronts (when fully sound deadened) can be crossed very low (around 65hz) with shallow slopes.
2. This allows the subwoofer to be crossed very low to (around 80hz) with a steep slope.

What this effectively does is get all the sound including the midbass at the front and only a thumping fill comes from the rear which is uni-directional. :)

This may be useless but when i hooked all mine up i had the same prob and all it turned out to be is the one thing no-one checks...... the engine earth. From the engine to the fire wall was a barstard little thing that was earthing out on paint and not bare steel. Make sure all your earths are on bare steel.

Yer it is 1KHz not 100Hz but I'm rebuilding it to 150hz as you suggested. I put all this together as a project (didn't know what value to cross at) to get a better understanding of the whole sub thing, so by getting this good feedback from yous I can hopefully fine tune it.
Body earth hey, good point thanks