I recently asked for help on a buzz problem and tried everything suggested with no luck. Here goes again....
I have a low level BUZZ that is independent of volume that comes on if the headlights are on. The speakers (all 4) also click with the turn signal and when the brake lights come on. The vehicle is a '98 Jeep GC with the Infinity 4 speaker system. I installed a PYLE 1000 watt amp after soaking the stock amp. The amp is driven from the high level speaker outputs from the head unit. The system sounds great in the daytime.
Initial suggestions were a ground loop. I set the system up to be powered from an independent external battery as a test. No change in BUZZ. It isn't the power side. What do I do now? Thanks for all your help.
Marc
Replies (11)
UKinstaller on 08/27/2005 11:54:08
did you run your RCA's down the driver or passenger side?? if you ran them down the driver side, they could be picking up noise under the dash where all your parking light, turn signal, etc. wires are located.
pick up a cheap set of RCA's, run them straight from behind the radio to the amp, don't hide them or anything like that, and see if your problem goes away. if it does, the problem is in the RCA's. if it doesn't, we'll try something else.
-UK
marcfc on 08/27/2005 17:03:40
I am actually using the high level outputs. I don't think the factory head unit has RCA outputs. Since the BUZZ is not volume dependent, doesn't that eliminate the head unit or wiring before the AMP as the problem?
swez on 08/27/2005 18:01:40
OK, we have to try some isolation tests to figure out where the buzz is coming from.
The first test, would be to use an audio patch cable whereby one side of the cable set is plugged into a Walkman or other portable player device with a stereo headphone jack. The other end of the wire, has a L&R set of RCA's that go to the amp input gains. Shielded wiring is recommended for this patch cord.
FYI: I have seen molded devices that have a stereo headphone male on one side and a pair of female RCA's on the other. That will work fine too. Here, you can use standard home audio RCA (male/male) wires.
Set amp gain controls at midpoint. (usually about 2 volts) Now try the system with engine on and off. Headlights on and off test too. See if you still hear the buzzing issue. If yes, most likely issue is the amp. Probably a noisy preamp or filters in same.
This issue still points to a ground loop problem between HU and amp. The fact you also noted "clicking" when the turn signals are on, is a pretty solid tipoff.
One other thing you can try, is grounding the HU to chassis, firewall or floorpan with a "dedicated" ground wire. That will help eliminate any dash cluster devices that share the same ground. These often contribute to ground loop issues. A dedicated ground will usually eliminate the ground loop and noise problems.
Finally, check amp gain setting. If amp gains are set below 1.5 volts, (very high sensitivity) this will also amplify noise as well as intended audio signals.
Good luck,
Swez COFFEE
marcfc on 08/28/2005 09:59:58
Swez:
Thanks in advance, again, for all your help. I did try the dedicated floor pan ground. I also used a "jump box" battery to run the amp independently of the vehicle's electric system, including ground. There was no change in the buzz with this set up. I will try the independent input source. I suspect the high level inputs as well. I just thought that the buzz would vary with the preamp signal if this was the case.
Marc
swez on 08/28/2005 10:25:46
No prob there Marc. We'll keep on pluggin away until resolution is found.
OK, you have a dedicated ground and a separate power source for the amp to date. Testing the amp with a different audio device will give us a few more clues as well.
This test will isolate the noise problem a bit more. If the buzz is gone when you perform this test, it suggests the noise is up stream in your system. (possibly a noisy HU)
If the buzz is still present, that suggests problems with the amp or gain settings on the amp are a bit off. Do you have a test meter? (AC/DC and ohmic scales) These are very helpful diagnotic tools. I have several and use them a lot for tracking down all kinds of electrical issues. WalMart carries a nice one for under $20.00.
GB Instruments: Model GDT-11
Digital display (easy to read)
Reads AC/DC voltages
Test diodes and transistors
Resistance measurements
Can test low DC current values
Swez
PS Your Jeep has an Infinity audio system right? Many of the upscale packages have Infinity HU & speakers. Some have amplifiers installed as well. This could be part of the problem as well. Especially if the system has a hidden amplifier and it got wet too. These amps are designed specifically for the Infinity HU's. That may be at the root of this issue. The aftermarket amp, may have some compatibility issues with that HU.
marcfc on 09/2/2005 14:22:07
Swez:
I finally got around to running an line level source to my amp. This eliminated the buzz. The buzz id definitly from the HU. Are their line level outputs from the Dodge HU? I have a shop manual with detailed wiring diagrams. (This is how I identified the wiring to install the new amp.) There is no indication that there are line level outputs. I highly doubt that there are. What other solutions are available to me? I would gladly replace the HU with an aftermarket unit it I can keep the stearing wheel controlls. Any ideas would be welcome?
Thanks again,
Marc
swez on 09/2/2005 15:21:50
OK! Now we know the amp is not specific to the noise issue.
Yes, you can use an aftermarket HU if you like. They have line level RCA's and many can be used with your steering wheel controls with the proper adapter kit.
Stock HU's don't normally have line level outputs. (only speaker level) However, there are conversion kits called LOC's (Line out convertors) that may work for you. Basically, they convert speaker level voltages (10 volts AC or more) to line level reference voltages. (2-4 volts AC)
Yes, they do work to a degree. However, a cheap one is often noisy as well. Also, if the noise issues are in the HU and mixed with audio signals, the noise will still be there with line level adapters.
Comments?
Swez
marcfc on 09/10/2005 11:31:30
Swez:
I have a new Pioneer HU on order from Crutchfield with the steering wheel control adaptor kit. It will not look as nice as the stock unit, but I am really getting tired of the BUZZ.
Thanks for the assistance,
Marc
swez on 09/10/2005 12:39:35
Good call on that choice. Which Pioneer HU did you order?
With a good install kit, your new HU should look pretty nice when installed. If you have a 1.5 or 2.0 Din space, there is room left over for other toys you may wish to add later like EQ or such. Our installer guru's can help you through the HU install if needed. But, Crutchfield offers a nice install instruction manual for these things as well.
Hollar if you need more assistance,
Swez
Victor on 09/11/2005 07:00:12
Hey guys, just a note on recent pioneer head unit experience,
On my trip to another city, i met many people who complained about problems with pioneer Hu's and i just thought i wud give some a look,
All of them had problems with the RCA outputs, most of them were shorting so it used to produce a continous buzzzzzz , as soon as another Hu was installed the sound is gone, and this happend in 5 cases, i dunno if its a manufacturing defect.. it cud have happend in a particular batch , but i cud not make it sure as those Hu, had the batch number stickers removed.
Cant also say if they were cheap duplicates, but they sure did look real in all the manner.
Jus wanted to say you cud be a bit aware and bench test the Hu's before buying them.
Victor
MrBrownstone on 09/12/2005 15:39:21
Where is the amplifer gain set? 90% of ground loop and noise problems come from sensitivity issues. The other 10% from poorly isolated equipment.
Just for everybody's benefit, RCA cables are incapable of picking up noise no matter where they are installed. You can wrap the RCA between the power and ground wires, run them along the length of the body of the vehicle, and it won't make a difference. Noise comes from the amplification devices (in the HU, sig processing, or amplifiers themselves) and not from the wires.
Remember, your whole CAR is a neg battery terminal.
If we start from the settings on the equipment, we'll eliminate 90% of noise problems rather than go through all the voodoo of where the wires are, do they have metal foil, etc.
:-)
PS Check out this system noise post
http://p205.ezboard.com/fcaraudioknowledgefrm7.showMessage?topicID=3.topic
I have a low level BUZZ that is independent of volume that comes on if the headlights are on. The speakers (all 4) also click with the turn signal and when the brake lights come on. The vehicle is a '98 Jeep GC with the Infinity 4 speaker system. I installed a PYLE 1000 watt amp after soaking the stock amp. The amp is driven from the high level speaker outputs from the head unit. The system sounds great in the daytime.
Initial suggestions were a ground loop. I set the system up to be powered from an independent external battery as a test. No change in BUZZ. It isn't the power side. What do I do now? Thanks for all your help.
Marc
Replies (11)
UKinstaller on 08/27/2005 11:54:08
did you run your RCA's down the driver or passenger side?? if you ran them down the driver side, they could be picking up noise under the dash where all your parking light, turn signal, etc. wires are located.
pick up a cheap set of RCA's, run them straight from behind the radio to the amp, don't hide them or anything like that, and see if your problem goes away. if it does, the problem is in the RCA's. if it doesn't, we'll try something else.
-UK
marcfc on 08/27/2005 17:03:40
I am actually using the high level outputs. I don't think the factory head unit has RCA outputs. Since the BUZZ is not volume dependent, doesn't that eliminate the head unit or wiring before the AMP as the problem?
swez on 08/27/2005 18:01:40
OK, we have to try some isolation tests to figure out where the buzz is coming from.
The first test, would be to use an audio patch cable whereby one side of the cable set is plugged into a Walkman or other portable player device with a stereo headphone jack. The other end of the wire, has a L&R set of RCA's that go to the amp input gains. Shielded wiring is recommended for this patch cord.
FYI: I have seen molded devices that have a stereo headphone male on one side and a pair of female RCA's on the other. That will work fine too. Here, you can use standard home audio RCA (male/male) wires.
Set amp gain controls at midpoint. (usually about 2 volts) Now try the system with engine on and off. Headlights on and off test too. See if you still hear the buzzing issue. If yes, most likely issue is the amp. Probably a noisy preamp or filters in same.
This issue still points to a ground loop problem between HU and amp. The fact you also noted "clicking" when the turn signals are on, is a pretty solid tipoff.
One other thing you can try, is grounding the HU to chassis, firewall or floorpan with a "dedicated" ground wire. That will help eliminate any dash cluster devices that share the same ground. These often contribute to ground loop issues. A dedicated ground will usually eliminate the ground loop and noise problems.
Finally, check amp gain setting. If amp gains are set below 1.5 volts, (very high sensitivity) this will also amplify noise as well as intended audio signals.
Good luck,
Swez COFFEE
marcfc on 08/28/2005 09:59:58
Swez:
Thanks in advance, again, for all your help. I did try the dedicated floor pan ground. I also used a "jump box" battery to run the amp independently of the vehicle's electric system, including ground. There was no change in the buzz with this set up. I will try the independent input source. I suspect the high level inputs as well. I just thought that the buzz would vary with the preamp signal if this was the case.
Marc
swez on 08/28/2005 10:25:46
No prob there Marc. We'll keep on pluggin away until resolution is found.
OK, you have a dedicated ground and a separate power source for the amp to date. Testing the amp with a different audio device will give us a few more clues as well.
This test will isolate the noise problem a bit more. If the buzz is gone when you perform this test, it suggests the noise is up stream in your system. (possibly a noisy HU)
If the buzz is still present, that suggests problems with the amp or gain settings on the amp are a bit off. Do you have a test meter? (AC/DC and ohmic scales) These are very helpful diagnotic tools. I have several and use them a lot for tracking down all kinds of electrical issues. WalMart carries a nice one for under $20.00.
GB Instruments: Model GDT-11
Digital display (easy to read)
Reads AC/DC voltages
Test diodes and transistors
Resistance measurements
Can test low DC current values
Swez
PS Your Jeep has an Infinity audio system right? Many of the upscale packages have Infinity HU & speakers. Some have amplifiers installed as well. This could be part of the problem as well. Especially if the system has a hidden amplifier and it got wet too. These amps are designed specifically for the Infinity HU's. That may be at the root of this issue. The aftermarket amp, may have some compatibility issues with that HU.
marcfc on 09/2/2005 14:22:07
Swez:
I finally got around to running an line level source to my amp. This eliminated the buzz. The buzz id definitly from the HU. Are their line level outputs from the Dodge HU? I have a shop manual with detailed wiring diagrams. (This is how I identified the wiring to install the new amp.) There is no indication that there are line level outputs. I highly doubt that there are. What other solutions are available to me? I would gladly replace the HU with an aftermarket unit it I can keep the stearing wheel controlls. Any ideas would be welcome?
Thanks again,
Marc
swez on 09/2/2005 15:21:50
OK! Now we know the amp is not specific to the noise issue.
Yes, you can use an aftermarket HU if you like. They have line level RCA's and many can be used with your steering wheel controls with the proper adapter kit.
Stock HU's don't normally have line level outputs. (only speaker level) However, there are conversion kits called LOC's (Line out convertors) that may work for you. Basically, they convert speaker level voltages (10 volts AC or more) to line level reference voltages. (2-4 volts AC)
Yes, they do work to a degree. However, a cheap one is often noisy as well. Also, if the noise issues are in the HU and mixed with audio signals, the noise will still be there with line level adapters.
Comments?
Swez
marcfc on 09/10/2005 11:31:30
Swez:
I have a new Pioneer HU on order from Crutchfield with the steering wheel control adaptor kit. It will not look as nice as the stock unit, but I am really getting tired of the BUZZ.
Thanks for the assistance,
Marc
swez on 09/10/2005 12:39:35
Good call on that choice. Which Pioneer HU did you order?
With a good install kit, your new HU should look pretty nice when installed. If you have a 1.5 or 2.0 Din space, there is room left over for other toys you may wish to add later like EQ or such. Our installer guru's can help you through the HU install if needed. But, Crutchfield offers a nice install instruction manual for these things as well.
Hollar if you need more assistance,
Swez
Victor on 09/11/2005 07:00:12
Hey guys, just a note on recent pioneer head unit experience,
On my trip to another city, i met many people who complained about problems with pioneer Hu's and i just thought i wud give some a look,
All of them had problems with the RCA outputs, most of them were shorting so it used to produce a continous buzzzzzz , as soon as another Hu was installed the sound is gone, and this happend in 5 cases, i dunno if its a manufacturing defect.. it cud have happend in a particular batch , but i cud not make it sure as those Hu, had the batch number stickers removed.
Cant also say if they were cheap duplicates, but they sure did look real in all the manner.
Jus wanted to say you cud be a bit aware and bench test the Hu's before buying them.
Victor
MrBrownstone on 09/12/2005 15:39:21
Where is the amplifer gain set? 90% of ground loop and noise problems come from sensitivity issues. The other 10% from poorly isolated equipment.
Just for everybody's benefit, RCA cables are incapable of picking up noise no matter where they are installed. You can wrap the RCA between the power and ground wires, run them along the length of the body of the vehicle, and it won't make a difference. Noise comes from the amplification devices (in the HU, sig processing, or amplifiers themselves) and not from the wires.
Remember, your whole CAR is a neg battery terminal.
If we start from the settings on the equipment, we'll eliminate 90% of noise problems rather than go through all the voodoo of where the wires are, do they have metal foil, etc.
:-)
PS Check out this system noise post
http://p205.ezboard.com/fcaraudioknowledgefrm7.showMessage?topicID=3.topic
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