Contour Enthusiasts Group Archives Forums Modifications Audio Capacitor Question

I'm tired of Capacitors. There's gotta seriously be something that I'm not doing, because every capacitor I get doesn't do me any good.
So let me tell you the situation. I have my nifty KnuKonceptz 1.0 Farad Digital Capacitor hooked to my Punch 500a2. 8 gauge wire comes from the battery to the positive side of the cap, then from the positive post of the cap through a 60A fuse and to the power input on the amp. Ground wire comes out of the amp, to the negative post on the capacitor, then from that post to a nut on the tail light (the area around it has the paint scraped). When I have the car running, the digital display reads in the neighborhood of 14.4 and when I turn the car off, it reads between 12.6 and 12.8. The problem is when I'm listening to the music and driving, after about 1 minute of low bass the lights start to dim and the bass doesnt sound as clean. I parked in a parking lot and played "woofer cooker" and when the first note in the song dropped, the digital display went from 14.4 to 12.8.
What is the problem? It actually seems like the lights dim more now that I have the cap. If the solution is upgrading the stock wiring, I would love to do that if I had adequate space to trace where the wiring goes. Anyone have a how-to on doing this? thanks for the help

try not grounding your amp to the cap and try to find a better ground spot and maybe even bigger wire.

Personally I would get rid of the cap.

A cap will attempt to maintain a full charge and with vehicle off.

That charge is maintained from the battery when the vehicle is off.

As a result you need more/bigger batteries for the cap when the engine is off, not to mention when the system is playing.

I'm not familiar with the amp you are using but caps are good for SQ applications where the amps need additional capacitance for transience.

Although for years many have used caps to reduce light dimming, today you will hear people speak of the BIG 3.

None of the 3 is a cap. Up gage all grounds and power from alternator and battery.

You want to improve the ground connections and wire gage from your battery to the frame (unibody) of the car.

For both power and ground I would use a 6 awg or larger wire based on your 60 amp fuse and assuming a 15 ft run of wire.

Move your amp ground and make sure it�s grounding to the frame (unibody). The lamp section may be providing a poor ground path through tack welds and bonded metal of the rear fascia.

Don't worry about any Alternator up grade.

It is a good idea and a part of the big 3 to upgrade the charge lead from the alternator to the battery.

With larger wire for both power and ground and better ground connections you should be able to omit the charge lead up gage, especially for engine off situations.

Make sure you have a good battery.

I have 1200 watts rms and 4 awg wiring as mentioned above with extra batteries with No Light Dimming.

Before changing anything, do you have a voltmeter other then the one on the cap? Check what the voltage is at the battery under the hood. My guess is that it does not fluctate as badly at the battery as it does in the back. It sounds like a ground problem. On the inside pass side rear wheel there is a metal lip with a factory hole. This is where SVT's have the power ANT mount. Use a bolt and nut with lock washer (scrap the paint clean off as well) Using a nut and bolt will ensure a very solid ground.

Upgrading the ground from battery to chasis under the hood is also a good idea.

Edit- Is the 60A fuse an inline fuse? If so that would be better placed under the hood near the battery. If ina D-block, then no problem. But if it is the only fuse in the system, it would be better off under the hood

Definatly put the fuse under the hood, as close to the battery post as possible. The use of a fuse is to protect your equiptment (and your car) in case there is a short. If tge fuse is all the way in the trunk, then thats about 10 feet of wire that is unprotected, and could cause serious damage if there were problems.

I had similar problems with the lights dimming. Upgrading to a deepcycle battery (such as an optima) fixed it for me. Caps are a band-aid to the wound... upgraded grounds, good battery, and possibly an alternator (if yours is capoots) should fix your situation.

I hate caps... I think they are almost useless... (almost)

Oops, I forgot to mention. 4 gauge wire is fused with 100A fuse inder the hood, and the 4 gauge wire goes through a distribution block, the cap is only on the 500a2, not the 360a2 because I figured the amp for the sub needed it more. But maybe I do need a better ground. Too bad the amp is on the opposite side of the antenna

A cap, when used properly, is effective in completing its task. IF your current battery and charging system can not keep up with demand, a cap will not solve the problem.

The proper use of a cap is to smooth out spikes in voltage in your system (it can also be a filter) Every amp has many small caps inside to stabilize the power supply. (some Zapco actually had seperate modules waaaaayy back in the day) Also MMATS added a cap bank to modified amps in SPL cars for burps.

Caps have a lower ESR so they can charge/discharge at a faster rate then a battery. They do not however ADD any power or reserve, they HOLD what is currently available.

So is the cap the answer to everything, no. When used correctly I would not call it a band-aide.

For more reading on caps, this thread was pretty good:
(i'll have to add link later, damn caraudioforum server sux)

Link added:
http://www.caraudioforum.com/vbb3/showthread.php?t=211794

Page two geolemon goes into good detail