New Alternator

After installing my amp and sub, I noticed that my lights have started to dim whenever the bass hits. I've read that capacitors only cover up the problem, and what I really need is a new alternator. I was just wondering what kind of alternator I should get. Like, how many amps would I need? I plan on having at most 2000 watts RMS when all is said and done.

2000 (watts out) / .85 (allowing for a 85% efficiency - very optimistic, BTW) =2350 (watts in) / 14.4v (engine running nominal voltage) = up to 165 amps for the system alone... Add to this all of the rest of the accessories in your car - lights, AC, wipers, rear window defroster, etc... easily 50 to 70 A, and you are looking at AT LEAST a 200A to 250A alternator.... Whatever you do, BUY THE BIGGEST ONE YOU CAN PUT UNDER YOUR HOOD... Don't just buy one that is "big enough", or "all I can afford right now". If that's all you have, but can wait to get a bigger alternator, do so... It'll be better for you in the long run. The more capacity the alternator has (even though you might not be using it all, all the time), the longer it will last... and there is no exception to this rule.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

That's why I figured 2000 watts. Right now I'm only running 600 RMS, but hopefully after another sub or two and then all new interior stuff, I'll be up around there. Apparently for a 200A-250A alternator, I'm looking at like $400-$500 though, so I'm probably just going to install the capacitor that I already have to cover up the problem (It's not THAT bad; just the slight dimming that I was looking for), and then I'll save up for one.