are three subs a bit overkill?

[Spyda]

without the powercaps every light that was on would basically turn off as soon as the sub kicked in

They work in theory.
On low volumes where the high current is only drawn ocasionaly they work because once the peak is gone, the cap can charge back up with the left over current.
On high volume where high current draw is constant the caps only add to the load. If your constantly drawing high current the cap is going to discharge and is going to be trying to charge back up.
There like inefficient batteries and usaly used as cheap short cuts.
For example if your car has 70amps to give and on low volume your amplifiers will draw 40amps than the cap can draw 30amps to recharge itself without taking any away from the amplifiers. If you turn the volume up and the amplifiers now draw 70amps (with peaks above 70amps that discharge the cap) the cap now has nothing to charge from without drawing current away from the amps or just being a expensive paperwieght.

The reason peoples lights dim is because the voltage drops as the current increases. As i said before 70 x 14.4 = 1008, if you increase the current draw the voltage has to drop for the total power to equal 1008.

Im running a total of about 1500watts RMS (so a bit shy of 3000peak) in the mk1, i dont have a cap or a 70amp alt but my lights dont dim.

[8v ggggti]

what amps are you using?

[Water Boy]

i used to have 4 10" subs on the rear deck of my Pug 205 lol

you can never have too many subs bro

Velly is so gansta!

[noone]

Sooooo much opinion and speculation. As an audio engineer, having built a few systems and having read a LOT of theory, I can say for sure:

Don't listen to other people, do what you want
What works for one car might sound average in another car
If you get a good quality amp and sub in a well braced box with good proportions, you don't need lots of power.

My only real requirements are: for small subs, make sure you have a spec sheet with all its parameters so you can build a ported / vented box that will work properly. For larger subs, sealed box is a win. Unless the box for the sub was designed for THAT sub, its going to have sweet spots and dead spots. you end up loving a few tracks that work well and most songs dont.

As for caps and things, they can help, but if you are serious about the power, get a bigger alt. I used to dim the lights in my Corolla with 400w for the sub and 200w for the speakers, you cant apply the electrical theory in such a linear fashion. A good 200w amp will lunch a cheap 1000w amp IMO.

[Spyda]

Don't listen to other people, do what you want

you cant apply the electrical theory in such a linear fashion.

I hear this alot, "do what you want", its not realy good advise, read up on how it all works then do what you want.
Basicly if it works for you and your happy with it then forgot about the rest. The more i learn the more unhappy I am with my sterio.

The electircal theory is just general, i thought that was clear?

[G-rig]

Why would you need a cap... i had three amps running and didn't have one..

[8v ggggti]

i dont know why but the lights were really dimming under heavy load from the sub but now they arnt so obviously the cap worked

[G-rig]

Ah fair enough, i haven't noticed that myself but then again haven't ran more than one 10" sub + 500W. Got a pro install, don't know if that affects it but don't hear much about 'caps' these days.