[Lou2]

Is it possible to use an aftermarket amp to boost the stock amp in order to send more power to the stock speakers?

[ctuna]

You won't get more power than the one that feeds the speaker.
Its not a multiplication effect you are just using the existing amp as
a preamp if thats what your asking.

You are getting more power but its at what ever the new amp output is
Amps may have multiple stages internally that do this as in preamp and amp
in one package.

IE if you have a 20 watt output channel you feed the signal into and amp
that has a 40watt channel output what you get is 40 watts not 20 x 40 watts.

If you want people to give you intelligent answers about how to modify
your system you need to identify which of the three BMW systems you have.


http://www.e90post.com/forums/attach...2&d=1260829447

Also the stock speakers on the base and hi fi systems are kind of cheap and won't
take a lot of amplification as they are 2 ohm and cheap they will sound better for awhile .

If you have the Hi Fi system the OEM amp is pretty easy to replace.

JL audio xd 600/6 is a perfect replacement(it fits has the same number of channels) but its wise to upgrade the speakers to.