Adding an Amp+Sub to Factory Head Unit - and how much power in the stock battery?

[zack726]

I recently helped a friend hook up a total after market system in his car - it was a lot of fun and the sound system kicks.

It got me interested in doing this to the Mini - problem being
1. Cost
2. MFSW

I'd love to leave the factory head unit in to keep the stock look (and it works fine), has anyone rigged up an amp and sub (not a complete system) to the stock head unit? Is a high -> low level converter (or low - > high) needed?

Or would you recommend a new head unit?

Also, I want to put in a 500W RMS sub powered by a 400W RMS Sub - a decent amount of power, but I'd think the stock battery can handle it. Anyone have experience with this? How much power could you do without a capacitor?

Thanks

-Zack

[adam_Randell]

Im having a massive problem getting a sub into my R56's standard system. I dont know if the R50/53 are the same, but i have been told th R56 is an amplified system so you have to tap into the speakers pre-amp i.e behind the head unit wich isnt easy in an R56. As far as cost goes its as much as you want to spend on a sub and amp. When you get the amp, make sure it has a 'High Level Input' as this is how you tap into your speaker cables to get the sound to the amp/sub.

Personally i would reccomend a new head unit, as it is a much more straight foward job and sounds much better than goin from the speakers.