Forcefedsi

iTrader: (1)

wats the best way to get rid of engine noise? i get this annoying high pitched sound out of my speakers (mainly my tweeters) when the engine is on and the deck is on but with no volume. the noise is worse if i rev or drive the car. i ran the rca's on the opposite side of the power and remote yet i still get engine noise. is there any filter i should purchase to get rid of engine noise or whats the best way to eliminate (if possible) engine noise? any help is appreciated, thank you.

XS Steve

What type of equipment and wiring are you using?

Tom.F.1

iTrader: (1)

Engine noise is usually caused by bad ground connection somewhere in your system.
This could be RCA's not grounded, deck, antenna, amps, chassis or battery.
Even though a connection my look good, it could be corrotion on the wire to crimp connection.
Best way to find it is use an omn meter, and measure all connections.
I use a pin to measure through the insulation and check connections through crimp connectors.

Forcefedsi

iTrader: (1)

this may be a stupid question but how do i ground my rca's? lol and would a direct ground from the deck to my batteries negative connection help?

Forcefedsi

iTrader: (1)

my system is as follows

MB quart tweeters and Blaupunkt 6x9's running off of a RF 300x 4 channel amp
2 JL Audio 10W3v3's running off a Kenwood KAC-9152D mono amp (4 ohm load)
Sony CDX MP70 head unit and pioneer door speakers running off the deck.

the gains on my 4 channel amp are pretty high... would it help to lower them a bit?

zzzzzzz

iTrader: (5)

get a meter ,set it to ohms test all -negs- in your set up .you can try to add a -neg- to the back of the deck and at the same time add a wire to the rca's to a -nag-
if you have a 0 ohms to all -negs- and still have a engine noise test your amp but i bo not think you will need to

Haunz

iTrader: (3)

You have a ground loop...

in some cases if there is a fault in the decks signal ground return hooking the signal ground of the RCAs directly to chassis ground can solve the problem.... IIRC this is most common with pioneer decks......


In any other instance... you need to break the 'loop'...
The best solution is to power your deck from an external power supply with a floating ground... other fixes are power supplies with active noise supression... sometimes simply adding an inductor to deck ground will filter the noise.... and a few others...

The best solution for most people that is cheap, simple, and effective... is a ground loop 'isolator' you put on the RCAs.... just make sure you buy a good one... they are basically 1:1 transformers and if they are not high quality the inductance of the windings will filter out your highs and they can also introduce distortion....

Kaiser

I got this from another of my posts.


I have wrestled with my whine for less than a year now and have done quite a bit to eleviate it. Here are some steps I recomend so far.

1.) Give your headunit a nice clean ground. this DOES NOT mean re run it to negative terminal of battery i tried that but in passing through the fire wall by my power it induced alot more noise. A nice chassis ground below the dash should work fine. Possibly even run a small wire from HU chassis to the HU ground.

2.) MAKE SURE ALL AMPS HAVE THE SAME GROUND. Also be sure its a good ground. This doesnt mean to a factory bolt. This means grounding block bolted to chasis and paint scraped and sanded down to bare metal around the spot.

3.) Possibly Fabricate a RCA low pass filter Circuit.This step works by crating a low pass filter for around 20kHz which shunts any AC signal above 20kHz to ground. You cant hear above 15Hz so no big loss and that annoying whine is a harmonic of the very high frequency that your alternator is putting out as it turns and changes frequencey as your speed changes. I have done this by taking scrap RCA jacks off of an old VCR or TV. Get ahold of 2 .1 micro farad capacitors (any type), one for each channel and run it from signal to signal common. MAKE SURE all your solders are nice or else you back to square one. once your done fabricating and you know you got it right, silicone the out of it so it wont short. This step helped me alot.

4.)Ground the Chassis of your amps to the same ground the amps share.


Also as another note, im using a 2 component filter which has a capacitor and a inductor.
WARNING your inductors will act as little antenneas and WILL pick up any EMI from Class D amplifiers, Neon Light Ballasts, EL wire Ballasts, and a whole wack of other stuff.

A solution to this is the isolation of your fileter circuit from the radiation rich environment of you trunk via a Radio Cage. But i think if talked to much. If anyone is interested in any more PM me!

PEace

Kaiser

I like that but how do you charge it? Not with the alternator...right

XS Steve

First off, you have all good equipment. Noise enters through your rca's in most cases. When running four channel amp's, placing your wires is very important. If you ran your rca's and power down opposite sides of the car your on the right track. When running rca's, I tape all three neatly together(front,rear,and sub). The reason is noise is picked up between the positive(center wire) and negetive(out side wire that looks like shielding)wire. When you only run one rca's, the noise you pick up is very low, but when you run two or three(in your case) rca's you have three positives and three negatives. The more space between your rca's the more noise you pick up. When I put mine together I tape the rca's 6 to 8 inches from the cd player to 6 to 8 inches from the four channel amp. You have to have a longer sub rca, so you can run it over to your sub amp. There are also better rca's you can buy called(twisted pairs). They are designed to cancel noise and any good stereo shop should have them in stock. Even if I use them I still tape them together. When running the rca's to the back of the car, keep them on the oposite side of the car from the power wire and away from any factory harnesses. Try to avoid power wires at all costs, but if no other way you have to cross a power wire, cross it at a 90 degree angle. That covers the rca's. If you do this there should be no reason to put any filter in, besides filters are just bandaids. They do not get rid of noise. There are a couple of other ways noise can get in. If the four channel amp is screw down to the body of the car you may be getting a ground loop there. Unscrew both amp to check this. If they are screwed into a box or any wood piece(making sure the screws don't go through the wood and touch metal) they should be alright. Now when fusing ampifiers, less is always best. Fuses are resistors that drop voltage, and the more that are in line on the way to your amp, they can cause the amp to pick up noise. The reason is there will be a difference in voltage from the cd player to the ampifier. It gets worse with more components(eq's, crossovers, line drivers, etc.). So when fusing, put the right fuse for the amplifiers at the battery. Do not use fuse block in the back, if you have to divide the power wire use powerblocks, or better yet a cap. Now with grounds on the ampilifers make sure they are tight and not anywhere that they can rust. One more thing to check is to see if your cd player is grounded properly. Take the player out of the dash and unhook the antenna. If the cd still powers up, your ground should be good. Last thing is setting the amplifiers properly. Turn all your gains on the amplifier right down, then set the cd players(bass, treble, loud,eq's)settings to flat or off. Next turn your decks volume full out, then back it off 2 or 3 digits. That's where your deck should be set to, now slowly turn the gains for front then rear up slowly making sure the sound is clean. After set your sub level. You should be done. Hope that helps you out.