realistically? nothing since capacitors are USELESS anyway, as I've explained to you many times now, ABfan.
In theory, the cap should be close to the amplifier to reduce propogation delay, so when the amp needs current, the capacitor can respond more quickly than the alternator. As long as the alternator can supply enough current, this will work, but if your alternator can't handle the strain and lights are dimming, a cap isn't going to do a thing.
ok i know it's useless whenever u use ur system with ur engine on, but as u know, during DB Drag competition, u cannot keep ur car on....at least in my category. Anyway thanks for the answer GW