Dang it! I can't get rid of the whining/humming noise after amp install!
01-10-2004, 01:09 PM
#1
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Dang it! I can't get rid of the whining/humming noise after amp install!
<center><img src="http://pictureposter.audiworld.com/52813/sub_install_2.jpg"></center><p>You guys remember I was asking how to go about to get rid of the whining/humming with an aftermarket amp in my A4 with non-bose 10 speaker system.
You can see above how I have the amp wired in.
I took the suggestions of people from the last post I made and nothing has helped. I shortened the ground cable to about 8", I tried shorter RCA cables, I shortened the power wire and moved it away from the RCA cable...I even shortened the remote turn-on wire. Finally, I tried a different grounding spot on the oppsoite side of the car...and nothing! I think MAYBE it got slightly quieter, maybe.
Anything else I can do short of going one of those ground loop thingajings?
You can see above how I have the amp wired in.
I took the suggestions of people from the last post I made and nothing has helped. I shortened the ground cable to about 8", I tried shorter RCA cables, I shortened the power wire and moved it away from the RCA cable...I even shortened the remote turn-on wire. Finally, I tried a different grounding spot on the oppsoite side of the car...and nothing! I think MAYBE it got slightly quieter, maybe.
Anything else I can do short of going one of those ground loop thingajings?
01-10-2004, 01:24 PM
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Couple more question for you..
1. Are you tapping into the rear outputs or the front? The front speakers are powered by the H/U, the rears and sub use the trunk mounted amp.
2.Where is the noise coming from? Your diagram looks like you only the amp for a new sub. Make sure that you have the low pass filter engaged on the amp. This can filter out some of the high frequency noise IF the noise comes out of the sub.
3.What brand of amp is it and where is it screwed down at?
It sounds like you have tackled the key issues, but are till getting a ground loop somewher in the system. In my ten years of working in the car audio industry, I have seen just about any kind of noise problem and the majority of the time it is ground related. The rest boils down to equipment-construction. We did a similar setup in my car a year ago for demo purposes of a steatlh install and had no noise issues at all, so it is possible in this vehicle.
2.Where is the noise coming from? Your diagram looks like you only the amp for a new sub. Make sure that you have the low pass filter engaged on the amp. This can filter out some of the high frequency noise IF the noise comes out of the sub.
3.What brand of amp is it and where is it screwed down at?
It sounds like you have tackled the key issues, but are till getting a ground loop somewher in the system. In my ten years of working in the car audio industry, I have seen just about any kind of noise problem and the majority of the time it is ground related. The rest boils down to equipment-construction. We did a similar setup in my car a year ago for demo purposes of a steatlh install and had no noise issues at all, so it is possible in this vehicle.
01-10-2004, 01:45 PM
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Are you using a signal converter for the sub amp input?
If not, then you really should since you don't have any dedicated pre-amp outputs.<ul><li><a href="http://www.crutchfield.com/cgi-bin/S-1bhp73WiEnA/prodview.asp?s=0&cc=01&i=101PL2&g=721h ttp://www.crutchfield.com/cgi-bin/S-1bhp73WiEnA/prodview.asp?s=0&cc=01&i=101PL2&g=721" >http://www.crutchfield.com/cgi-bin/
01-10-2004, 01:49 PM
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Re: Couple more question for you..
<center><img src="http://pictureposter.audiworld.com/52813/ground_backseat_sm.jpg"></center><p>1. I'm tapping into the line-level wires from the HU to the stock amp in the rear.
2.Its definatly coming from the rear in the trunk...so I can only assume it the sub making the noise. I do have the low pass (80Hz) filter enabled.
3. It is a Rockford Fostage 150S amp. It is the same amp/sub combo I had in my Civic, and I had no issues with noise there. So I know it's not the amp itself. It HAS to be something with the way it's setup or something.
Right now it's not screwed down, it's just sitting on floor in the back of the trunk.
I was just outside working on it, and I removed the wire taps from Radio Shack and hard wired the wires directly to the stock amp wiring...thinking maybe there was a problem there, it made no differance, same noise.
Should I maybe try a different gounding point? I used the one in the picture above...even tried the one on the other side of the car in the same locations...hell I tried using both at the same time! NOTHING!
2.Its definatly coming from the rear in the trunk...so I can only assume it the sub making the noise. I do have the low pass (80Hz) filter enabled.
3. It is a Rockford Fostage 150S amp. It is the same amp/sub combo I had in my Civic, and I had no issues with noise there. So I know it's not the amp itself. It HAS to be something with the way it's setup or something.
Right now it's not screwed down, it's just sitting on floor in the back of the trunk.
I was just outside working on it, and I removed the wire taps from Radio Shack and hard wired the wires directly to the stock amp wiring...thinking maybe there was a problem there, it made no differance, same noise.
Should I maybe try a different gounding point? I used the one in the picture above...even tried the one on the other side of the car in the same locations...hell I tried using both at the same time! NOTHING!
01-10-2004, 01:51 PM
#7
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Its not needed...
Because the stock headunit has line-level outputs that go from the headunit to the stock amp.
Other members on here have wired it the exact same way with no noise issues.
Other members on here have wired it the exact same way with no noise issues.
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01-10-2004, 02:00 PM
#8
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Which HU output are you stealing the signal from?
Being a parallel signal you could be getting feedback from the stock amp. Your new amp is probably pulling too much current. The in-line signal line leveler should help this.
I had a similar setup a while back on a much older car and I had a similar issue. Putting the signal leveler in solved my issue.
I had a similar setup a while back on a much older car and I had a similar issue. Putting the signal leveler in solved my issue.
01-10-2004, 02:03 PM
#9
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YOU'RE ON TO SOMETHING!!!
You gave me an idea to go out and pull the harness from the stock amp.
Gues what? NO MORE NOISE!
The aftermarket amp still works because it's getting a signal from the HU.
Ok...so we are narrowing this down. You said something about feedback from the stock amp? And a line-level converter would solve my problem?
I don't want to lose my rear speakers so I have to figure out how to make this work. I know some people completely disconnect the stock amp...I don't wanna do that though.
Gues what? NO MORE NOISE!
The aftermarket amp still works because it's getting a signal from the HU.
Ok...so we are narrowing this down. You said something about feedback from the stock amp? And a line-level converter would solve my problem?
I don't want to lose my rear speakers so I have to figure out how to make this work. I know some people completely disconnect the stock amp...I don't wanna do that though.
