Amp woes

[grimbo]

I had to remove my amp and sub from my boot last week.

I put them back in today and it's gubbed. It's a 4 channel amp - running a set of components in front and a sub in the boot on 2 bridged channels. Now the speakers keep clipping, when I turn on the car the frequency increases to an almost constant noise in front and a big whu-whu-whu in the sub....

I have double checked the rca cables are correct. I have reset all filters on the headunit and the same on the amp. If I turn the volume up the music plays and you can't hear the background noises but it's still there adn it pretty much rules me out of listening to music quietly.

I don't know what's happened - any ideas? Could the earth be causing problems? Where's a good place to earth an amp in the boot of a mk3 golf?

thanks!

[Heyho]

Sorry to hear about that.

The best place to earth you amp is to the closest piece of CLEAN bodywork.  What make is your amp?

[grimbo]

It's a FLI 800. It's breaking my brain. The sound gets worse with the revs - would this indicate an earth problem or something else?

[tommk3cab]

i have had this problem, along with many others but cannot quiet recall the cause, however either the earth, the standard place to use is under the back seats where the seatbelts attach, or as above any clean unpainted bodywork,  the boot catch is always good, if it doesnt stop the boot closing, as is, if accessable the point where the back seats hinge in the boot. the most probable cause however is the remote turn on wire to the amp from the HU, try disconnecting this wire from the amp and temporarly bridging from the 12v main power wire to the remote turn on terminal ON THE AMP! a small (inch long) bit of spk cable should do it the noise should go away, i know the problem is easily sortable. the noise you hear is radiating from all electrical sources including the vent fans i suspect producing a high pitch whistle! annoying? yes! these steps should sort your problems and have you rocking in no time!

[grimbo]

This morning I bridged the remote on from the live. No Help.

I moved the earth a few times. No Help.

The noise is like a clicking the speeds up to an almost constant noise when the engine is on and quicker again/ more high pitched when I rev.

I'm going to have to pick up some new rca's I think and see if that helps in anyway. I can't think of anything else!

[monzablue16v]

RCA's are worth checking or it might be your suppressor on the alternator has gone they are quite cheap to replace it's a little block with a wire on that fastens onto the bolt side of the amplifier.

[boneybradley]

sound's like interferance with your wire's....have you changed where the wire's run as the rca's can pick up background interference? I had a similar problem which I fixed by buying an rca ground loop thingy from haulfrauds and this cured mine...It was explained that my rca wire's were picking up excess current from being to close to some live wire somewhere,Trust some spotty 14 year old knowing more than me!!!!!

[tommk3cab]

you can try but im pretty sure its to do with one of the things i mentioned above, dodgy rcas will normally just cut in and out, it could even be an amp fault but if it was working fine when you removed it then this will be unlikely depending on where it was kept when out of the car as long as it didnt get wet there should be no problem. thinking about it, did you take the headunit out, if you have speakers running off HU and if the noise is through those speakers too then the amp is not the cause but the headunit is. check the pins on the connector block in the back of the stereo, both sides male and female, look very close, one hopefully will look bent or as if it has been. The earth (black wire) probably or another wire to the headunit will be causing the problem in this case. could be need for rf loop supressor or alt supressor as above but i doubt it.

[grimbo]

Haven't moved the routing of the wires at all. I have rcas one side and the power down t'other.

I might pick up one of those rca ground loop thangs anyway - can't hurt.

I just kept the amp in my house, didn't get wet and just sat there! I haven't had the HU out. My rears run directly off the HU and they are still playing fine. It's defo something to do with the amp/wiring...

I don't know where these supressors are!? Will they be visible or inside the amp?

[monzablue16v]

The supressor is fastened onto the alternator. looks a bit like this