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New Amp installation, now static on all 4 channels

Posted: Fri Jan 18, 2008 10:22 am
by ryboto
I just bought and installed an Eclipse EA4100 to replace an XA2000 for powering 4 speakers. For the installation I ran new power/ground wire and added a second RCA cable for the rear channels. The RCA's run on one side and are Knuconcepts that have a built-in remote wire. The power runs along the other side, and the ground is in the trunk. I measured battery potential between the poles, and then potential across the + and - terminals on the amp and they read the same.

When I turn on the radio, I get static in all four channels, only when music plays. It's like distortion, but it's just relative to the music volume, so it doesn't get "worse" when I up the volume, it just gets louder as the music gets louder. It doesn't drown out the music but it's annoying and sounds like a tinny mp3. I've tried changing RCA cables for the two different channels, unplugged them, reseated the power cables, and still, static. Tried doing the same for the wire brackets at the head unit, still static with music. It's not alternator whine, as it happens if the engine is off. There isn't any noise added when the engine is on. So, if anyone has any suggestions, please suggest them! Thanks!

Posted: Fri Jan 18, 2008 1:17 pm
by William from NOLA
Have you played with the gain knob at all? What about any other settings inside the HU or on the amp?

You may want to check behind the HU to make sure no RCA's are inadvertantly touching metal and that the ground is sanded down and secure.

Posted: Fri Jan 18, 2008 1:46 pm
by ryboto
William from NOLA wrote:Have you played with the gain knob at all? What about any other settings inside the HU or on the amp?
You may want to check behind the HU to make sure no RCA's are inadvertantly touching metal and that the ground is sanded down and secure.
I've tried the gain, it's at the highest now, changing it doesn't change the level of static relative to the music. I also pulled the RCA's out so they were free from the dash to make sure no metal could touch them. The ground is the same that I was using for the previous amp, and is very secure.

Posted: Fri Jan 18, 2008 2:19 pm
by cargodz
ryboto wrote: The RCA's run on one side and are Knuconcepts that have a built-in remote wire.
Have you tryed running a seperate remote wire?

Posted: Fri Jan 18, 2008 2:39 pm
by ryboto
cargodz wrote:Have you tryed running a seperate remote wire?
Could a remote wire cause this kind of issue? It's not a constant hissing, it only occurs with the music. I can try using a separate remote, but not right away.

Posted: Fri Jan 18, 2008 2:48 pm
by William from NOLA
I'm wondering if you're overdriving the inputs. What are the HU preout voltages and the amp's?

Posted: Fri Jan 18, 2008 4:05 pm
by ryboto
William from NOLA wrote:I'm wondering if you're overdriving the inputs. What are the HU preout voltages and the amp's?
I can't remember, the head unit output might be on the 2-4 volt range. I don't see why it would be an issue though the EA4100 has the same gain ranges as the XA2000 and they both provide the same RMS power. The Amp has a gain dial from 0.2-8v.

Posted: Fri Jan 18, 2008 6:19 pm
by ryboto
Could it be that the amp was just too cold? Previously, I'd only listen for a minute or two, but I was in my car just now for a half hour and after about 5 minutes, the tinny static was gone. These seem like a possibility?

Posted: Fri Jan 18, 2008 6:20 pm
by cargodz
Maybe if you had some moisture in your car

Posted: Fri Jan 18, 2008 6:23 pm
by ryboto
cargodz wrote:Maybe if you had some moisture in your car
Maybe in the air in the trunk there's more moisture, but when I just looked at the amp it was perfectly dry, incredibly cold, but dry.