I am planning out what will hopefully be the best sound system I've built, and I have a question on capacitors. Of all the systems I've built over the years, I have never used caps, although some could have used one. Now, I'm building an Alpine/JL Audio system for my '79 Z. It's gettin a CDA-9856 Alpine reciever running Alpine MRP-F450 4chnl and an MRP-M650 monoblock all pushing a set of JL's TR690 6X9's and probably Eclipse 3.5" up front w/a JL 12W6 in the trunk. I've heard rumors that the M650 kicks the wattage up into the 800 range. With all this in mind I'm going for sound quality with abit of bump and I want to make sure the amps get the cleanest, smoothest power flow possible. I've seen other systems running .5 farad up to 5 farad capacitors. Now for the question. How do I choose the right cap? Do I go for the 1.2 and have the faster charge rate but loose out on storage?, or, go with the 3 to 5 and gain storeage but loose out on charge time? I would apreciate any input.

The rule of thumb is about 1 farad for every thousand watts you have, now this really depends on the condition of your charging system. The big advantage to a cap is that it releases power really fast, so that your amp does not have to struggle to pull it out of your battery. I would say you should be fine with the 1.2 but the bigger caps are reasonably priced any more so that would be a good option, as far as charging time I dont think you will ever even notice a difference. The rockford demo vehicle out of minneapolis was running two amps that were rated at 500 watts each but push over a 1000 each off of a 100 farad cap last year. So I would buy whatever the budget allows, but go atleast the 1.2

Thanks for the reply O2, that clarified some things now I know what I'm gonna do. Thanks