I was having a terrible engine noise problem after the recent install of my 4 channel amp. We figured out the problem wasnt coming from the amp but from the head unit and on. So i tried regrounding the head unit and nothing worked. So i tried out a device called noise filters they worked great took care of the problem right away but now the sound quality is terrible any advice on what i should do are there certain adjustments that should be made on the amp when the noise filters are added? The amp is Audiobahn (a4004t) model with a panasonic head unit model 5400 with alpine dhb speakers all the way around. Any advice would be great!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spoolingb20 &raquo;</TD></TR><TR><TD CLASS="quote">I was having a terrible engine noise problem after the recent install of my 4 channel amp. We figured out the problem wasnt coming from the amp but from the head unit and on. So i tried regrounding the head unit and nothing worked. So i tried out a device called noise filters they worked great took care of the problem right away but now the sound quality is terrible any advice on what i should do are there certain adjustments that should be made on the amp when the noise filters are added? The amp is Audiobahn (a4004t) model with a panasonic head unit model 5400 with alpine dhb speakers all the way around. Any advice would be great!</TD></TR></TABLE> What kind of filter did you use, one that gos on the power wires of the HU, [chocks] or one that connects to that RCAs, [ground loop isolater]? 94

 

Sorry i should of stated that I used the ones that connect to the RCA's .

 

how did you determine the noise was comming from the head unit?

 

The way that i tested it was unplugged the RCAs from the amp and then turned everything on the noise was gone. By doing this I believe that then it has to be either the RCAs or the head unit. I then ran a set of RCAs with the head unit sitting on the seat and the RCAs run ontop of the seat to the amp. The engine noise ws still there. So that is how i determined that it was the head unit. Maybe not the headunit it self but somewhere from the head unit on into the harness there is obvisiouly a bad ground. ( I have already tried running new grounds for the head unit also)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spoolingb20 &raquo;</TD></TR><TR><TD CLASS="quote">The way that i tested it was unplugged the RCAs from the amp and then turned everything on the noise was gone. By doing this I believe that then it has to be either the RCAs or the head unit. I then ran a set of RCAs with the head unit sitting on the seat and the RCAs run ontop of the seat to the amp. The engine noise ws still there. So that is how i determined that it was the head unit. Maybe not the headunit it self but somewhere from the head unit on into the harness there is obvisiouly a bad ground. ( I have already tried running new grounds for the head unit also)</TD></TR></TABLE>Did you unplug the radio ant.? Does it make any diff. in the noise level if the HU is in or out of the dash?

What kind of noise is it? is it a whining, whistling kind of sound the changes in pitch when you rev the motor a little, and increases in volume when you turn more stuff on in the car? [lights, rear window defog, heater]

Or is it more of a buzzing, fast ticking sound?

Can you hear anything when you turn on the sig.lights, step on the brake, or use any switch in the car? [on and off]

There are a few ways noise gets into the system, and its a good bet that its getting into the HU, [as the GLI seems to get rid of it] try this, after making sure the ground on the amp and HU are good, run a wire from the HUs chassis to the amps chassis, [dump ground] The other thing I would try is another HU, some brands just will not work with some other brands. 94