Aaron

alright. part of my new system is in now. i have had in an ALPINE CDA-7894
KENWOOD COAXILS, US ACOUSTICS SUB AMP, and INFINITY KAPPA sub.
my new amp and components were installed by a shop about an hour away from me because they sold the kind of speakers i wanted and i wanted a good install. i went with DEI 5 1/4" component set in the front with a new US ACOUSTICS 4085 running them.

i don't want to waste my time going back to the shop unless i have to. it's quite a drive and if this is something i can fix myself with help i would rather do that.

problem #1 i have engine whine! i did'nt have this before so i assumed it was a bad ground on either the HU or one of the amps. i called the guy that did my install and looked at his work. both the amps are grounded to a bolt in the back. it looks like a bracket for the seat. the connections are sitting on top of the bracket with the bolt going thru them and the bracket to the car. mind you i already had the alpine and the sub and sub amp installed(somewhere else) so this is a new problem. the HU he said is grounded to the amp all the way back in my trunk. is this right? i thought grounds should be as short as possible. i can especially hear the whine when i have the air conditioning running. it is SO annoying!

problem#2 i get an amp click or pop when i turn the car on. i never had this before either. it seems to be coming thru all the speakers. the amps do have a turn on delay built in to address this i believe.

this install guy was'nt that helpful when i talked to him. he said the grounds should be good. he said i may be getting noise from the RCA's wich are decent cables. they were run on the opposite side of the car as the power cables too. if its from the RCA's he said i can get a noise isolater inline with the cables that will get rid of most of the noise. i feel i should'nt need one of these if the install is done right.

what can i try myself to fix these problems? he said that cheaper amps are more prone to noise too. i understand that US ACOUSTICS are'nt the cream of the crop for amps but i read ALOT of good things about them and my sub amp has been working great so far.
PLEASE HELP!!

BTW... the speakers sound great. i just need to get rid of these damn noises!

Aydu

Noise in your system means there is a problem with the install. The shop that did the work should have checked this out before they turned the car over to you, but they frequently either don't check at all or just check to make sure the parts work.

I'd take the car back to them and politely, but firmly, express your dissatisfaction with the work. They can isolate where the noise is coming from, and fix the problem. The issue is time - it takes some to find and correct these problems.

Bad grounds are a frequent cause of noise in a system. Any decent shop can test the quality of a ground with some simple electronic test equipment (not expensive stuff, more the simple $20 test meters. Often regrounding solves the problem.

If they try to sell using filters as a solution, don't buy it. Noise filters just hide the problem, they don't solve it. Often, these filters degrade the overall sound - either on the high or low end.

It sounds like you spent good money for your components and the installation. Asking for a noise free system is just asking for the performance you have already paid for.

If they cannot get the noise out, they should refund the cost of the install. This would give you some cash to pay someone with more skill to fix the problem their install caused.

Dave Cameron

It sounds like two things, alternator whine, which is either coming in on the power lines themselves to the headunit of amp, or induced noise. When you use RCA lines the small low power lines can pickup noise from things they are close to. Sometimes the actual lenght of the line causes induction of noise.
This is fixable either way, but induction can be a real challange to find isolate and fix.
You are right, gound close as you can on the chassis, the chassis is the biggest gound of them all, and is the path of least resistance on a car, the wire will have much greater resistance. Try to aviod anything to do with the air conditioner for grounding, that little electric motor in there is famously "dirty" in terms of electrical noise.
I would agree and disagree on the filters. Only buy them if they work, and get it agreed to up front that after riding with them for a week if you don't think they make a lick of difference, you can return them. But I have installed them and they can work, they are basically a choke to regulate current, and try to keep it constant. I have seen then used in competition cars, and no one ever got counted off for it! Isolators go on powerlines though, not RCAs, RCA isolators are voodoo.
The second problem sounds like a turn on thump, which means the amp is coming on before the headuniit. You need to find out how they hooked up the amp turn on wire. A sharp shop should be able to fix this for you. Read in the manual and see if there is a delay option on the headunit.
This also can be fixed.
The shop should make it right. Find out the experence level of the installer, sounds like he is learning off you.

Aaron

i have to say that the work he did do looks good. he did a flush mount of the tweeter in the door and the cables are tied up nice in the back. this really ticks me though. because like you say..... i paid GOOD money for this to be done right. do the ground connections for the HU HAVE to be to the chassis. it is currently wired back with the sub amp to the amp's ground connection and another wire goes to the chassis. also the connectors are resting on the seat bracket itself and not touching the metal of the chassis. but they are all bolted down together. does this matter? i would really like to figure this out but if i fail i will certainly go back to the shop. this NEEDS to be fixed. it's just such a long drive for me to make considering the other things i have to do with my time.

thanks guys. keep any other opinions coming if you can.

Dave Cameron

short grounds are better, long wire runs do have have signifigant issues with resistence, and the chassis will win out as attractive as a ground plane in a car. Some installers, myself included, used to use "star" topology for grounds, having every ground go to one center location. Over the years I came to the conclusion that this lends itself more to ground loops, not less. Have gound close and to the chassis, bare metal if possible. The set belt bolts make great ground points in the rear of a protege.
I would suggest that you let the installer fix it. As an attourny, I can tell you that if you attempt a fix, and by accident hardware is damaged or the situation made worse, you have clouded your case for a legal redress. Nicely put, a judge would say you may have dystroyed it yourself.
The underlying legal principle if you are interested is borrowed capacities. You (unless you are a medical doctor and a brave one at that) would not attempt to operate on yourself for a brain tumor. You would find someone who knows what they are doing and pay them to do with the expectation they would get it sucessfully done for you. Same with pilots, or structural engineers, we contract with them to use their knowledge.
In your instance, you contracted with a installer to knowledge of how to do a install that looks good, and sounds good. You have recieved only half of what you contracted for, indeed with sound being a major part, less than have probably.
Call them and let them know you are after a solution, clean sound, and you will be back until you get the sound you went in expecting. See what they say. Assuming you allowed them to do everything they wanted to do during the install, and they now refuse, you have breech of contract. The primary deliverable was not met.
Makes a little sense?

onehawaiian

yeah, if you paid good money for it, then just have them check your system, isolate the problem and fix it. i have never had a "perfect" installation, and things do need to be tweaked and checked again. but hey, u paid for it so u want to be sure u are happy with the end result.

Aaron

and this should be able to be fixed without putting some sort of noise blocker in line with the rca cables, right? cause he said they may be the cause and that thing with cheap amps. i just don't buy that. those will hurt the signal coming to the amp, won't they? i'm gonna see if i can get over there today to have them look this over.

Aaron

well............ i took it back to the shop today. the guy turned down the gain on my amp and then we could'nt hear much noise at all while revving the engine. i asked him again about the ground and he said it was good. both amps are grounded to the seat bracket..... on top of the bracket, not underneath. after reading some other stuff on grounds, this does'nt seem to be the greatest place for a ground but i'm not sure. check this article and see what you guys think. this even says that seat belt bolts are rarely a good choice for a ground spot. hmmmmmmm.

http://www.eatel.net/~amptech/elecdisc/battgrnd.htm

also.... he did'nt really have a solution for amp "turn-on pop". he said that amp must not be delaying the signal like the sub amp is. hmmm. they are both the same brand of amp. both amps are supposed to have a turn on delay in them. why is it fricking popping then??

oh and when i left i could still hear some engine whine when i turned the music down but when i shut my HU off i could still hear it so i must be getting some noise just from the engine and not my system then? strange. maybe it's always been that loud but i never noticed it.

Aydu

One simple test is to disconnect the RCA leads to your amps. If you still hear engine noise with the RCAs disconnected, the noise is being picked up by the amp. I'd try another ground spot - short as possible, on bare metal.

If the noise stops when the RCAs are disconnected from the amp, you are getting noise either from the RCA cords themselves or the grounding of the head unit. One test for the RCA cords is to run a separate set from the head unit to the amp with the cords running outside the car. This helps ensure that the RCAs are not picking up noise from inside the car. Being too close to the amp power wire or other signal wire can cause this.

If the noise is still there with different RCAs, it is likely the grouding of the head unit. Trying a new ground for the head unit is the answer, until the noise is gone.

As you can see, this takes time - and time is money to a shop. Turning down the gain on your amp leaves the noise in place, it just amplifies it less so it is not as noticable.

I've had shops try the quick fixes on me, but when I've continued to demand satisfaction they always end up doing the trouble shooting to get to the root of the problem. On my last install, I had them working on eliminating noise for 3+ hours - at no additional charge - and finally got a noise free, good sounding system.

These tests are not rocket science, and known to anybody in the business of doing car audio installations. Most modern car audio components handle noise pretty well in their design. Problems are usually with the person putting in the component.

I'd go back yet again and demand, politely, that there be no noise in the system that was not there when you first brought the car to them. If components are misbehaving, they should have the ability to try a substitute to verify that something is malfunctioning. If they can't try another amp or RCA cord, they are either not much of a shop, or don't really care about a satisfied customer.

Aaron

now i've got a new noise!!!!!!!!!!!!!!!!!!!

i'm really getting frustrated. i get in my car this morning and drive to work. i turn up the tunes. it was loud but really not THAT loud. i start hearing this crackle sound from the speakers. i tried to isolate the sound..... if it was the front or the rears. i seemed to hear it in both though i did'nt have a whole lot of time to look at things. i called the shop and the guy is gonna look at it again on friday. he said it could be bad rca's or a speaker is blown. BLOWN!!!??? what the hell? all this stuff is brand new including all the cables and wires!!! what can be causing this? i did'nt really hear the noise when i turned the volume down but i did'nt have to have it up super loud to hear it either.

then when i left work for home i hear no noise. i tried to get it to do the same thing with no luck. do you guys have any suggestions for me before i bang my head against a wall?

obender66

I am going through same problems as Aaron.
I did install myself, so I have nobody to blame. Amp picks up noise, not RCA's. My noise is present only when I use power mirrors.
When I get chance I will re-ground it. Right now it's bolted to passenger seat mounting bolt.Any other suggestions?
As for crackle-it may be defects on CD. play same CD over and see if it appears again.
Alex

Aaron

i played the same song again this afternoon to see. no noise.