I have a constant whining noise on my speakers which rises in pitch as the revs rise. (alternator noise) The power cable to the amplifier is on the other side of the car as the RCA cables leading to the amp. I even put the remote power-on cable to the amp on the same side on the car as the main power cable. I cant figure out where this whining noise is coming from. Its only when the car is turned on.

I have an a 2000W 4 channel amp in the trunk. 2 channels are bridged to run the 12" subwoofer. The other 2 channels run the 2 6x9's. The front 2 speakers are directly run from the head unit. The car is a 1999 civic 150i (d15z4 - the one's found in south africa)

Now its supposed to be alternator noise you pick up when the power cable is next to your RCA cables. But the cables are at different sides of the car. So I dont know... Is this probelem honda-specific? Because a friend of mine with a mazda doesnt have this problem.

If anyone can give advice on how to eliminate this constant whinig noise it will be greatly appreciated! Thanks...

 

Need a lot more info...

1- Make and model number of the amp, [2000W amp is no help]?

2- Make and model of the HU?

3- Make and model of the sub(s)?

4- What gauge is the power and ground cables for the amp?

5- Where is the amp grounded, to what and how?

6- How long is the ground cable?

7- Where is the amp mounted, to what, is the chassis of the amp grounded?

Need answers to all 7 questions


Alt. whine is almost always caused by a ground loop, [a differance in ground potential between HU and amp] and although the noise can be induced into the RCAs if the RCAs and main power lead run together for any length.

Noise can also be induced into RCAs that are running down the power side of the car, [the side of the car that all the power leads for things in the back of the car run down, fuel pump, tail and brake lights and so on].

It is always best to make all leads/cables as short as possible, run them the shortest possible way.
EG; power cable down the side of the car the batt. is on, RCAs down the center of car, amp control lead can run with the RCAs, [very low current].

One more thing, you should be using the amp on the front speakers and use the HUs internal amp to drive the rear speakers, it will give you much better staging and imaging, you need very little power, [watts] for "rear fill". 94

 

First of all- thanks for the reply!

Ok now to answer the questions:

1. The amp is a Ice Power PS2000 4 channel. 100W RMS x 4channel and 300W RMS x 2 channel. I dont know if Ice Power amps are available in te usa/canada. It's kind of a budget amplifier.

2. Head unit is a Sony CDX-GT350.

3. The sub is a 12" Sony XS-L124P5B

4. Both the power and ground cables are 8ga.

5. The amp is grounded at a spot next to the left taillight with the 8ga ground cable. I used a lug at the end of the wire and scraped the paint off the ground location.

6. The ground cable is about 2 - 3 feet long.

7. The amp is sitting loosely in the trunk of the car. However, I put a rubber mat in the trunk so it cant move around. The chassis of the amp itself isnt grounded.

The RCA cables are running down the left side of the car (the side the battery is on) I'll switch them to the right side and switch the power cable to the left side and see if it helps.

Another question though: My front speakers are Sony 6" with only 40W RMS. Will they be able to go loud enough if I wire them to the amp and wire the rear 6x9's to the HU?

Thanks again.

 

I would start by shortening the amps ground cable to as short as possible, and ground it to the floor pan of the car, seat and seat belt bolts/studs work very well and go into the cars floor pan in front of rear axle.

Only switch the RCA leads if there are other leads running to the rear of the car on the left hand side.

Are cars in SA left or right hand drive, wiring to the rear of the car would normally run down the drivers side of the car, [the side the under dash fuse box is on]. 94

 

The cars in SA are right hand drive.

I'll leave the wiring as it is and get a better grounding point. I've been wanting to get a better grounding point since I installed the amp but if you delay something enough you eventually just forget about it!

If changing the grounding point doesn't work out I'll try different wiring routes to the back of the car anyway.

 

I grounded the amp to one of the seat bolts. It's a much better grounding point than the previous one by the looks of it. BUT... I still have that whining sound.

The RCA's aren't on the side of the under dash fusebox.

I don't know what do... Any other advice?

 

Run a "dump ground" from the chassis of the HU to the chassis of the amp. 94

 

fcm, maybe the trick that solved my pioneer noise? try this. https://honda-tech.com/zerothread?id=2316812

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by patrick4588 &raquo;</TD></TR><TR><TD CLASS="quote">fcm, maybe the trick that solved my pioneer noise? try this. https://honda-tech.com/zerothread?id=2316812</TD></TR></TABLE> Same thing, your grounding the chassis of the HU to the chassis of the amp. 94

 

how is that the same thing? all i did was put a piece of stripped wire in the rca plug in. ill take your word for it, but i dont get it

 

You didn't ground the other end to the amps chassis? 94

 

How do you set up the "dump ground" wire?
Do you connect the ground wire of the HU to the ground wire of the amp?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by patrick4588 &raquo;</TD></TR><TR><TD CLASS="quote">fcm, maybe the trick that solved my pioneer noise? try this. https://honda-tech.com/zerothread?id=2316812</TD></TR></TABLE>

I stripped some wire and put it in the RCA plugs but it didnt help. The whine is stille there.

 

You ground the chassis of the HU to the chassis of the amp.

I always run a dump ground when mixing brands, EG; Pioneer HU and anything but a Pioneer amp, I us a ring terminal to connect one end to the HUs chassis, normally I use the back support screw/stud location, I will run it along with my RCAs and amp control lead and connect it to the amps chassis using one of the chassis screws and a small ring terminal.

To try it I have a long lead with alligator clips at both ends, clip to HU chassis and to the amps chassis, running it over the carpet and seats if I'm just checking.
One of 3 things will happen, nothing at all, the noise goes away, [or is reduced] or the noise gets worse.

All you need to do is connect one end to the HUs chassis, turn the system on, [car running] and touch the other end to the amps chassis and see what happens, no point in running the lead if it does not help or noise gets worse. 94

 

Thanks for the detailed advice. Anyway I tried it but it didn't make any difference. I took some speaker wire and connected it to the HU's back support screw and the other end to the amp chassis. The noise is still there. It didnt increase or decrease, it stayed exactly the same.

Is there anything else I can try?

 

I tried using another RCA cable- a better insulated one with the wires wound around one another, but it didnt make any difference.

 

Time to try another HU or another amp.

First try this, unplug the RCAs at the HU, start car and turn system on, is there still alt. noise?

Also, before you unplug the RCAs can you tell where the alt. noise is coming from, front or rear speakers or both? 94

 

what brand rca's are you using? you said you tried another set, but if those were cheap too, then the problem wouldnt subside.

fcm, no i didnt run a wire to the amp. just put the copper in the rca. that was it

 

the problem is that you do not have enough grounding from your amp to your chassis, here I have the same problem but haven't had time to sort it out, hope it helps

 

LOL, let's hope he got it fixed, the tread is from July 2008. 94