I have the 700 watt sound system.
I just replaced the stock Alpine speakers with Focal PC100's (x2 door, x2 rear).
They sound amazing, but they don't balance with the front speaker or the sub-woofer.
Adjusting the base down to the lowest notch and fading the speakers to the rear helps, but I suspect there is a mixer/amp somewhere that requires replacement or adjustment.
Any audio gurus out there?

 

You do not mention which car you have but the amp for the DB9 is on the back wall of the trunk, behind the carpet as you are looking into it. No adjustments available apart from whats in the head unit.

 

The car is a 2011 Vantage V8.
I didn't mention which car because I suspect the solution requires a mixer or amplifier from another vendor.
Thanks :-)

 

if they are too loud i would think (and could very well be wrong about this) a volume control (a simple rheostat) or some suitable resistors might be useful on each new speaker wire. if they lack amplification compared to the other speakers, yes some sort of amp might be necessary. and no, i am no guru. i had a yearly subscription to Audio magazine back in the 70's for about half a decode or so and i make a pretty good margarita, but that's about it.