subs thumping out of tune

[PaulD]

that may be right .... if you're gonna use your headunit's internal amps, you have to adjust your outboard amps to be consistent with the output of the headunits internal amps. Otherwise, one will distort badly when the other is in the normal operating range

[jazer80]

sorry i explained it badly; it is the rear speakers, which are running off of the amp that are distorting. i recently got brand new rca's (which solved this problem when it was happening to my subs), so they should be fine. i'm gonna go check out the grounding, make sure they're grounded to the same place. i'll post a little later

[jazer80]

okay they were both grounded to the same spot, and i checked it out and the ground is good. also i adjusted the front speakers (which get power from the receiver) and the rear speakers to get them balanced and this did nothing to lessen the distortion.

[maximafever]

Okay I'm going to try and explain this as best as possible and simple as possible. If you have your power and rca wires ran on the opposite sides of the car and you still are getting a whinning noise and distortion then you have a ground loop problem and the best way to fix the problem is to put a filter on the device causing the problem. From what you have stated before you need a filter at least on your deck if you are running one rca from the deck to your amps. If you are running two rca's from your deck to both amps then you should first put a filter on the amp running your highs. sometimes you will need a filter at the deck and at the amps. In my previous setup in my 95 Maxima with 110 amp alternator, Deep Cycle battery, 600watt x1 Bazooka Amp, 200watt MTX Amp, 2-12" MTX Thunder6000 subs in a sealed box I had to use filters to get rid of the engine whine. Same setup in my 87 Honda Accord have to use filters. The nice thing about filtyers is that they are easy to install just plug the rca's into the plugs then plug the other end into the source. I don't know what audio shops you have but if you have a Wal-Mart just go pick up a ground loop isolator in the car audio dept. for about $13.00 plus tax. also a tip on amping your door speakers run you speaker wires from your amp all the way to your deck and the wire should be at least 16gauge you run that size wire cause the signal path is longer and you don't want to lose sound running smaller wire would be worst. Also for better sound run the amp on your front speakers and make sure you set your amp on high pass filter, you will like the sound a lot better and you may not need to even have a rear fill. there's a lot more I could say on how to hook up your system but I'll stop there. I have hooked up many systems so I speak from experience. If you have any questions post them here or email me at [email protected].

[ponchonutty]

Originally Posted by jazer80

sorry i explained it badly; it is the rear speakers, which are running off of the amp that are distorting. i recently got brand new rca's (which solved this problem when it was happening to my subs), so they should be fine. i'm gonna go check out the grounding, make sure they're grounded to the same place. i'll post a little later

Dude, your problem has to be with your amps. You stated that before you had no noise and everything was cool until your backpack hit it and you replaced the amp. Then all of the sudden you have noise. You should never have to use those cheap filters and such. Those just tone done the noise. You just treat the symptom and not the cause. You never see a $20k system with filters all around. You did good things by moving RCA's around and away from power but with good quality RCA's you usually do not have to worry about that anyway. Now, one thing that it could be is your car's battery. If you've been working on your system with the battery still hooked up, you could have worn out your weak battery. Sometimes you can have a weak battery but not really notice it but it makes your altinator run like crazy. This high charging output will cause radio noise. To do an easy test, unhook the RCA's behind the radio and start the car. If you still have noise, you have something else going on. If you don't, then you know that it is with your radio or battery/charging system.

[jazer80]

if the problem is the amp is it possible that the same amp works fine when i hook it up to my subwoofers? i'm pretty sure the amp's fine. i know my battery (optima) was very good a month or two ago, but i guess i don't understand how i would mess up my battery by working on the system with the battery hooked up? as far as unplugging the rca's and trying that, all i have to do is turn the radio off and the noise goes away. the noise is definitely coming from my rear deck speakers, so if i unplug the rca's, i disconnect their power and they turn off, and the noise is gone.

[jazer80]

i'm assuming that since the noise is only present when the engine (and the alternator) is turned on, it has to be related to the alternator (i think). the last time i had this distortion, and it was only present when the engine was on, it turned out to be poor quality rca's. swapping them out fixed the problem. what other things do you want to check when the problem is in all likelihood related to the alternator

[maximafever]

Of course the problem is with the amps and the reason you hear it in your speakers running highs is because the whine is a high pitch whine in which your subs cannot play. You have to remember that electricity has a humming noise that is with it. So when the power from your baterry is being transfered to your amps your amps is going to try and pass that noise off as a signal. You ask why it only happens when the engine is running and why it gets louder. The answer is simple when your car is in accessorie mode it is only sending about 12volts to your amps which most amps are able to surpress but when you turn on the engine you can be sending as much as 14volts to your amps in which all of the noise is not able to be surpressed and the higher you rev the engine the more power your alternator is putting out. That is why I say use a noise filter, the noise is not hurting anything except our ears cause we have to hear it when we are not listening to the music loud. There are other things you can do like change your amps out for some high end amps that have filters built into them to handle the noise, but that's a lot of money to put out just to get rid of a noise, the other thing is try a different deck but I have had Sony, Pioneer, and JVC and had the same problem with them all. Most $20k dollar systems have the best amps on the market, the best rca's, the best decks, upgraded auto electrical system, and the best wiring and even some of them have to use filters, but that is something that you wont read or see to often. There is a lot of things that are used in car audio to be sure to get a clean sound you have to be really into it to know it. I don't think that he worried about having a competition system he just wants to be able to drive around in peace except for the music coming from his CD's or radio.

[PaulD]

alternator whine problems SUCK ...and you would be surprised how many high dollar installs use them because the installers don't know how to troubleshoot this problem.

[jazer80]

oh i get it when you said it was my amps i thought you meant they were broken, but you're saying that they are just picking up the noise, and that higher end amps probably wouldn't, right? i guess i'll just have to end up trying the filters. hate solving problems that way but looks like i'm out of options. thanks for the input everyone

[ponchonutty]

Originally Posted by jazer80

oh i get it when you said it was my amps i thought you meant they were broken, but you're saying that they are just picking up the noise, and that higher end amps probably wouldn't, right? i guess i'll just have to end up trying the filters. hate solving problems that way but looks like i'm out of options. thanks for the input everyone

Well, not too quick here. We need to make sure that the noise is actually being pickup or generated by the amps or the stereo. Do this, leave everything connected and put a jumper between the turn on and the 12v constant on the amp(s) in question. Then start the car with the radio off. Here you should have the amps on but the radio off. If you don't hear engine noise, you then now know that it is comming out of the radio and not from the amps or RCA's. If you do hear noise, unplug the rca's then and see what you get. If don't, there's the problem. If you do, then it's the amplifiers that are picking up the interferance.

Now, even the last being said your problem actually could be the altinator or battery. If your altinator is putting out major amperage for some unknown reason, you'll get noise each and every time no matter what system you got in your ride. I had that in my brand new car and it was driving me nuts. Here the altinator was already shot after 2k miles!!!!

[jazer80]

ponch, sorry but could you explain this like you would to a child, i really don't wanna blow sometyhing up; when you say connect the 12v constant to the turn on, does that mean to connect, via a speaker wire maybe, the power terminal to the remote turn on terminal? and when i do this, do i leave the other wires (remote and power wire) connected?

[jazer80]

yo ponch....

[ponchonutty]

Originally Posted by jazer80

ponch, sorry but could you explain this like you would to a child, i really don't wanna blow sometyhing up; when you say connect the 12v constant to the turn on, does that mean to connect, via a speaker wire maybe, the power terminal to the remote turn on terminal? and when i do this, do i leave the other wires (remote and power wire) connected?

YES The amp turn on input is a low amperage switch. It actually goes to an internal relay that "clicks" when it sees 12v+. Leave everything else on or hooked up (except the turn on lead from the radio since you will use a jumper wire). So then you will do the above steps to investigate where the noise is really coming from.

[PaulD]

when you do this, you need to make some shorting plugs for the rca inputs. Every input on theamp needs one. A shorting plug is just an RCA end that has both poles or wires just soldered together. This will short the amp input, to prevent it from picking up stray noise.