Engine Noise W/New System!
06-23-2005, 10:56 AM
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Engine Noise W/New System! Just installed a new pioneer head unit w/2 amps and a CD player. I have the infamous engine/alternator whine that varies with RPM. I have pulled the RCA's from the amps and that seems to cut the noise out (i guess that rules out the part of the system from the amps to the speakers), so it's probably one of the following:
1) Bad RCA's from receiver to amps
2) The fact that I have ran my RCA's along the 12v amp power cables throught the car.
3) Bad ground or other problem with the receiver?
Anything else you guys can think of and how can I diagnose the problem from here? What is the most likely to be the problem?
1) Bad RCA's from receiver to amps
2) The fact that I have ran my RCA's along the 12v amp power cables throught the car.
3) Bad ground or other problem with the receiver?
Anything else you guys can think of and how can I diagnose the problem from here? What is the most likely to be the problem?
06-23-2005, 11:04 AM
#2
I think you pretty much answered your own question with #2 above.
In too many places in this forum as well as others, the recommendation is to keep rca's and power wires far away from one another.
How did you ground the headunit? Using the stock ground wire in the harness?
It would be interesting to see if you get noise with the speakers powered directly off the head unit.
Something else to try is use an ipod or similar portable audio player to provide the signal for the amps. Since the audio player is run off of batteries, its isolated from the car's electrical system. If there's no noise then I think its likely that your source of noise is the head unit or rca's.
In too many places in this forum as well as others, the recommendation is to keep rca's and power wires far away from one another.
How did you ground the headunit? Using the stock ground wire in the harness?
It would be interesting to see if you get noise with the speakers powered directly off the head unit.
Something else to try is use an ipod or similar portable audio player to provide the signal for the amps. Since the audio player is run off of batteries, its isolated from the car's electrical system. If there's no noise then I think its likely that your source of noise is the head unit or rca's.
06-23-2005, 11:09 AM
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Originally Posted by GPz1100
How did you ground the headunit? Using the stock ground wire in the harness?
It would be interesting to see if you get noise with the speakers powered directly off the head unit.
Something else to try is use an ipod or similar portable audio player to provide the signal for the amps. Since the audio player is run off of batteries, its isolated from the car's electrical system. If there's no noise then I think its likely that your source of noise is the head unit or rca's.
06-23-2005, 11:24 AM
#5
The oem harness should be ok.. I have no problems here [yet.. no amp in the system yet].
By unplgging the rca's, you're leaving the inputs open in the amp. It could possibly pick something. Amplifiers can display unusual characteristics if they are not biased with anything. With an external audio source there is a signal present.
It would still be worth a shot to see if you get noise with the HU powering a set of speakers only.
You used a good ground for the amp too? Scrapped away the paint surface, etc...
---------
edit:
It just occured to me.. if you've exhausted checking your wiring, relocated rca's away from +vcc line, thoroughly checked your grounds, it could possible be an issue with the alternator itself.
In my old car (mid 80's chevy taxicab), not only did I have alternator whine, but had ignition static too (built in audio tach).. Very nasty stuff. Got it resolved by experimenting with different ground points for the head unit (all metal dash interior of that car).
By unplgging the rca's, you're leaving the inputs open in the amp. It could possibly pick something. Amplifiers can display unusual characteristics if they are not biased with anything. With an external audio source there is a signal present.
It would still be worth a shot to see if you get noise with the HU powering a set of speakers only.
You used a good ground for the amp too? Scrapped away the paint surface, etc...
---------
edit:
It just occured to me.. if you've exhausted checking your wiring, relocated rca's away from +vcc line, thoroughly checked your grounds, it could possible be an issue with the alternator itself.
In my old car (mid 80's chevy taxicab), not only did I have alternator whine, but had ignition static too (built in audio tach).. Very nasty stuff. Got it resolved by experimenting with different ground points for the head unit (all metal dash interior of that car).
06-23-2005, 03:14 PM
#6
What kind of noise is it ? Like a buzz? if it is like a suttle but still annoying buzzing sound then you may have a ground loop problem caused by having two components such as amps grounded in the same place and connected via another medium such as RCA cable to a component grounded someplace else. This can be solved with a ground loop isolator that you can pick up at radio shack for less than 20 bucks plugs right inline with the RCA that sounds like the problem to me hope that fixes it !!
06-23-2005, 03:43 PM
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2) The fact that I have ran my RCA's along the 12v amp power cables throught the car.
Also, the little wire that runs down the rca's (if you bought a good pair) is used a ground. Most people use it as a remote turn on or their amps.
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06-28-2005, 06:53 PM
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route your power cables in one side of the vehicle and try to keep away from other wire harnes such as power seat or lighting those carry constant 12v. The same goes for you signal wires (RCA). As for the ground point DONT ground two amp together and try to keep ground cables short as possible and put them directly to body panel free of paint. The oem harness for the head unit should be good enough.
06-28-2005, 07:12 PM
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it could be radiating from your spark plug wires, if you have aftermarket ones, to the rca's, which would cause the noise. in that case, just place some noise limitting filters in there to cut it out.
06-28-2005, 08:00 PM
#11
#1 for alternator noise is bad grounds.
#2 would be RCA induced.
#3 Equipment.
Where is your ground, and how good is it? Did you use Sandpaper to get all the paint off the contact point. A Good GRN is imperative.
I would unplug you RCA's and see if there is noise. If none, you still need another input or shorting plugs to isolate the amp, or external.
Tape the RCA's on the outside when installed in the dash. I've seen the outside shields touch the ground of the metal brace and induce noise.
Here are some steps to try:
1.) unplug the RCA's to see if you still have noise. If yes, it's the Amp or PWR. (just saw you did this)
2.) Unplugged RCA's no noise, Plugged in noise. Can still be gound (the amp now has a signal to process). Easiest test is to pull the RCA's out and see what the issue is. Start by pulling the HU out of the dash. That's easy. Move the RCA's out from the cavety to where you can see them.
Still have noise, Move the ground for the amps. It needs to be a good ground. F-bodies have crapy choices in the back for ground. Don't use the Antenna bracket. Too week. I'm trying to remember where I grounded my amp at. (it was stolen so I can't go look.)
After that, if you have noise, it's RCA time. Pull them out and run them directly from the HU to the amp's down the center of the Car.
If you have noise, I'll say HU, and possibly the AMP. Have to use shorting plugs to eliminate the amp entirely. (Get RCA's ends or Cheap RCA's and short the center to the outside ground.)
I don't think Spark Plug wires. EFI computers are more sensitive to induction noise from the Coils than the stereo equipment. All our aftermarket wires are built for noise suppression.
As for the remote turn on wire, It is a filtered +12v feed from the HU. So induced noise would have to come from the HU and you would have noise everywhere.
Induced from a Power wire is possible, but less likely than most people are believed to think. It is still a Damn good Rule of thumb to keep power and signal seperated, but not the end all, be all. EFI car's can induce noise more easily thru the Ground than the power. Ground is alway's just so-so in a car. They are not designed with Aftermarket Installs in mind.
#2 would be RCA induced.
#3 Equipment.
Where is your ground, and how good is it? Did you use Sandpaper to get all the paint off the contact point. A Good GRN is imperative.
I would unplug you RCA's and see if there is noise. If none, you still need another input or shorting plugs to isolate the amp, or external.
Tape the RCA's on the outside when installed in the dash. I've seen the outside shields touch the ground of the metal brace and induce noise.
Here are some steps to try:
1.) unplug the RCA's to see if you still have noise. If yes, it's the Amp or PWR. (just saw you did this)
2.) Unplugged RCA's no noise, Plugged in noise. Can still be gound (the amp now has a signal to process). Easiest test is to pull the RCA's out and see what the issue is. Start by pulling the HU out of the dash. That's easy. Move the RCA's out from the cavety to where you can see them.
Still have noise, Move the ground for the amps. It needs to be a good ground. F-bodies have crapy choices in the back for ground. Don't use the Antenna bracket. Too week. I'm trying to remember where I grounded my amp at. (it was stolen so I can't go look.)
After that, if you have noise, it's RCA time. Pull them out and run them directly from the HU to the amp's down the center of the Car.
If you have noise, I'll say HU, and possibly the AMP. Have to use shorting plugs to eliminate the amp entirely. (Get RCA's ends or Cheap RCA's and short the center to the outside ground.)
I don't think Spark Plug wires. EFI computers are more sensitive to induction noise from the Coils than the stereo equipment. All our aftermarket wires are built for noise suppression.
As for the remote turn on wire, It is a filtered +12v feed from the HU. So induced noise would have to come from the HU and you would have noise everywhere.
Induced from a Power wire is possible, but less likely than most people are believed to think. It is still a Damn good Rule of thumb to keep power and signal seperated, but not the end all, be all. EFI car's can induce noise more easily thru the Ground than the power. Ground is alway's just so-so in a car. They are not designed with Aftermarket Installs in mind.
06-28-2005, 09:18 PM
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I do many installs on Fbody cars and ran into this many times in the beginning!! It is always wise to run RCA on oppisite side of power but not always the problem
It seem to be a phantom problem same install on a hundred diff f-bodys and about 5 have problem.
I use inline noise filters behind the deck for the RCA's no loss of sound quality and has always fixed the problem.
Also ground most people use the bolt holding the rear passanger seat belt the material that the wire touches is not metal besides the bolt and nut itself leading to poor ground.
It seem to be a phantom problem same install on a hundred diff f-bodys and about 5 have problem.
I use inline noise filters behind the deck for the RCA's no loss of sound quality and has always fixed the problem.
Also ground most people use the bolt holding the rear passanger seat belt the material that the wire touches is not metal besides the bolt and nut itself leading to poor ground.
06-28-2005, 09:34 PM
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yeah, i've seen so many rca's right next to the + wire and no problems.
an issue that has recently came up, try grounding the shields of the rca's and see what happens. that would be the outside connection on it, do not touch the center.
you can even call pioneer and they will tell you it is ok to do it, and especially do it if it isn't their amps you're using.
an issue that has recently came up, try grounding the shields of the rca's and see what happens. that would be the outside connection on it, do not touch the center.
you can even call pioneer and they will tell you it is ok to do it, and especially do it if it isn't their amps you're using.
06-28-2005, 10:23 PM
#14
Originally Posted by joesmith136
Also ground most people use the bolt holding the rear passanger seat belt the material that the wire touches is not metal besides the bolt and nut itself leading to poor ground.
What ground point do you recommend?
06-30-2005, 12:38 AM
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OK, here is where I'm at:
1) Pulled RCA's from the amp and the no noise. Put shorting plugs in the amp and no noise. Ran RCA's through the center of the car, noise still there.
2) Gave receiver a new ground. Noise still there (with RCA's attached). I even tried running a positive wire straight from the battery to the receiver, and noise is still there.
Here is the interesting part: When the key is turned backwards to the accessory position, there is no noise at all (except some popping when power windows are used), when I switch the ignition forward to the ACC position, a buzzing/hissing noise comes on, where I start the car, I get a crazy loud whining noise that changes with ther RPM's. When I pull the RCA's from the amp, none of these noises are there.....I am starting to think that I have a bad head unit (its a new Pioneer)......PLEASE HELP!
Here is my total system layout:
1) One 4 channel amp
2) One Mono sub amp
Both amps grounded to same place on chassis (good ground)
3)Pioneer head unit (ground to chassis)
4) Pioneer CD changer (ground to same place as amps)
1) Pulled RCA's from the amp and the no noise. Put shorting plugs in the amp and no noise. Ran RCA's through the center of the car, noise still there.
2) Gave receiver a new ground. Noise still there (with RCA's attached). I even tried running a positive wire straight from the battery to the receiver, and noise is still there.
Here is the interesting part: When the key is turned backwards to the accessory position, there is no noise at all (except some popping when power windows are used), when I switch the ignition forward to the ACC position, a buzzing/hissing noise comes on, where I start the car, I get a crazy loud whining noise that changes with ther RPM's. When I pull the RCA's from the amp, none of these noises are there.....I am starting to think that I have a bad head unit (its a new Pioneer)......PLEASE HELP!
Here is my total system layout:
1) One 4 channel amp
2) One Mono sub amp
Both amps grounded to same place on chassis (good ground)
3)Pioneer head unit (ground to chassis)
4) Pioneer CD changer (ground to same place as amps)
06-30-2005, 01:21 AM
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UPDATE:
I just took a portable cd player and plugged it in to the rca cables going to the amps (at the back of the receiver) and everything sounds just fine. The noise is coming from the head unit....now, can this be fixed or is the head unit bad?
Gave receiver a new ground. Noise still there. I even tried running a positive wire straight from the battery to the receiver, and noise is still there.
Here is the interesting part: When the key is turned backwards to the accessory position, there is only some noise at all (some popping when power windows are used), when I switch the ignition forward to the ACC position, a buzzing/hissing noise comes on, where I start the car, I get a crazy loud whining noise that changes with ther RPM's. When I pull the RCA's from the back of the receiver, none of these noises are there.....I am starting to think that I have a bad head unit (its a new Pioneer)......PLEASE HELP!
I just took a portable cd player and plugged it in to the rca cables going to the amps (at the back of the receiver) and everything sounds just fine. The noise is coming from the head unit....now, can this be fixed or is the head unit bad?
Gave receiver a new ground. Noise still there. I even tried running a positive wire straight from the battery to the receiver, and noise is still there.
Here is the interesting part: When the key is turned backwards to the accessory position, there is only some noise at all (some popping when power windows are used), when I switch the ignition forward to the ACC position, a buzzing/hissing noise comes on, where I start the car, I get a crazy loud whining noise that changes with ther RPM's. When I pull the RCA's from the back of the receiver, none of these noises are there.....I am starting to think that I have a bad head unit (its a new Pioneer)......PLEASE HELP!
06-30-2005, 02:28 AM
#17
When you changed the ground, did the sound get worse? or stay about the same.
If the same, then it's a bad HU. It's a Fact of Manufacturing that stuff sometimes slips thru the Quality Control.
Pioneer uses an inline filter for the power wire. If that is missing then that may/may not be the problem. Can try an inline power-line filter to see if it helps, but I'm not thinking it will. The poping noise with the Power windows and stuff is symptoms of a ground loop, but you haven't indicated anything else that would cause that. You even moved the ground. At this point it's more than likely the HU.
If the same, then it's a bad HU. It's a Fact of Manufacturing that stuff sometimes slips thru the Quality Control.
Pioneer uses an inline filter for the power wire. If that is missing then that may/may not be the problem. Can try an inline power-line filter to see if it helps, but I'm not thinking it will. The poping noise with the Power windows and stuff is symptoms of a ground loop, but you haven't indicated anything else that would cause that. You even moved the ground. At this point it's more than likely the HU.
07-01-2005, 07:59 PM
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I have the same problem with the whining, but mine doesn't whine at all until I start the engine. Does your get louder with volume control? If so it could be the signal from your hu.
Mine doesn't vary with volume, I think mine has to do with the 12V turn on.
Mine doesn't vary with volume, I think mine has to do with the 12V turn on.
07-04-2005, 12:26 AM
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ground the shield of the rca, trust me. i bet your head unit is damaged, but this should knock the noise down greatly. if you get it warrantied, leave the rca shields grounded. solder them on.
