Got a mate who is installing a sound system and just wondering what would farad capacitor would be best for him. He has a 500rms 1500w Sub. 2 Amps. One to power the sub. And the other to power the speakers. And speakers (80+RMS) running off the amp. Would a 1 farad capacitor be enough to do the job?

he won't need one. just get a new battery (century from kmart is like 120, or just go nab one from bob janes lol) and also get some nice new brass battery terminals. a cap is a waste. if he wants wank factor he should get ione of the ones that looks like a NOS bottle with the gauge on top with the amp reading. thats about all it will be good for.

so your telling me it wont dim the headlights etc? or stress out the alternator? each bass hit?

Capacitor is a waste of time. If the battery and alternator are healthy should be all that is required. Upgrading the earths can make an amazing difference to the electrical system also. Run some additional earth cable (4 gauge) from battery to chassis with good clean contacts and engine block to chassis, can make a noticable difference. Dont wast coin on caps.

Really, you guys frown upon capictors that much? what if the subs need a huge ammount of power for the big bass, how can the alternator/battery supply that much without causing dimming. i thought a capacitor is a must for any decent sound system?

I chucked one in mine its a 2 Farad, just for the reason that you could see the lights were stressing just under full load of sound.