power cable for amp

[pong]

as mentioned in my previous post,

i purchased a 400 watt amp. blaupunkt gta 4100.
there is this weird whining sound whenever my aircon
and headlights are on.

accdg to the person who installed it... there is not
enough power going to the amp.

the solution... run a gauge 8 or 10 wire straight from the
battery (+) to the amp... of course... a fuse somewhere
there...

the question is: where do you suggest me letting the wire run?
i wouldnt want to run it inside the cabin (removing carpets and all
is out of the question for me)... thinking of the underside of
the car...

what do you guys think?

[Blitzkrieg Bob]

there are some heavier gauge wires supplying power to the goodies under there.

[Tiger]

Since battery is under seat... it is real easy to fish new wire from battery to trunk. Fuse must be within 12" from battery.

The whining noise is nothing to do with cable thickness... it is because of poor ground. You need to connect the amp to the chassis... where it contact the chassis, the surface must be BARE metal... not painted.

[pong]

Since battery is under seat... it is real easy to fish new wire from battery to trunk. Fuse must be within 12" from battery.

The whining noise is nothing to do with cable thickness... it is because of poor ground. You need to connect the amp to the chassis... where it contact the chassis, the surface must be BARE metal... not painted.


my battery is in the front of the car. not under the seat

[Blitzkrieg Bob]

In the engine bay.

[Hypr5]

A few things here :

The distance you are running - if thats a true 400w amp, at 4 ohms, 8 gauge should be your absolute minimum and at 2 ohms, you should be running 4 awg. wire to be on the safe side.

Running it under the car will be just as big of a pain (if not bigger) than just lifting the side of the carpet and tucking it under. It shouldn't take much longer than 20 - 30 minutes to run it.

Also, noise when other electronics are running is rarely an issue of too little power - it's usually an issue with the ground that you have selected. Try Re-grounding to the nearest seat belt bolt and see if that helps.

[Karl]

If your battery is in the fromt of the car, there is still a terminal under the back seat, as if the battery were there, with heavy gage wire to the battery.

In fact I used that terminal in my car to relocate the battery. When the battery in front gave out, I got an Optima sealed battery, put it under the back seat, and picked up the connection there. Works like a champ.

[joshua43214]

Car stereo installation can be odd stuff, it been a few years since I researched it for my old car. High powered systems need special care that low power sytems don't. At a certain power threshold, wire routing and proper grounding becomes very important

I would be highly suspect of the whine coming from not enough power, as stated though, if you really have a 400w amp you need a big wire to feed it. It is undoubably a ground problem. keep in mind some car stereo set ups require every thing be grounded a single ground lug and the head to be grounded straight to the chassis. googling car stereo installation should net some good descriptions.

The other possibility is that you simply have a wire running to close to a high voltage wire, this could be either a power wire or a speaker wire. Whine when turning on accessories or whine when you turn up the volume but run no signal are common problems from installation error and should be easy enough to track down.

[rockyfeller]

Ground is most likely though you can also get noise/interference from your RCA wire. Make sure to run this cable independently away from the power wire. Other wires can also interfere with this one as well. Invest a couple more bucks on a quality well shielded wire with quality end jacks. I had a loose connection once that gave me a whine. 8 GA wire is enough for the ground. Do 4 GA on the power if you can and wire the fuse close to the battery. A 1 farad capacitor will help too.

[Incantation]

make sure your ground wire is at least as big or preferably BIGGER thank your power wire.

THIS IS VERY IMPORTANT YOU CAN"T "get away" WITH A SMALLER GROUND YOU WILL RUIN YOUR SYSTEM. PROPER GROUNDING IS WAY MORE IMPORTANT THAN USING THE RIGHT POWER WIRE