Jake --

Congratulations on being one of the few car audio enthusiasts who, in my admittedly biased opinion, is doing things right!

You do NOT need big boxes full of 12" subwoofers and kilowatts of power to have a great sounding system. You will find, as you build your system, that the most important aspects are number and size of speakers, the acoustic characteristics of the vehicle itself (best results from a large vehicle interior with lots of cubic feet of air to move around), and most important of all, speaker location. Sounds like you are off to a good start.

Your PPI amp has, I think, a built-in crossover at about 90Hz for your 10" subwoofer. Try it crossed over, then press the button and try it full range. You might be surprised at which way you like better. Your RKB-100's also have crossovers built into them, probably around 3,000 Hz, I don't remember. You probably will not need any additional, external crossovers. Remember, too, that the empeg will (eventually - are you listening, Hugo? ;-) have a 20-band parametric equalizer built into it that will allow far more tuning than you could ever do with crossovers.

My only concern with your system is mid-bass. Maybe those 6x9's will cover you in the 200-1000Hz range, maybe not. You might consider a pair of 6" MB-Quarts in your doors, mounted as high as you can and still keep the windows working. Those 4" RKB-100 MB Quart speakers you mentioned will probably turn out to be the best stereo investment you ever made, except possibly the empeg. ;-)

You might also give serious consideration to not doing the line-out business to the secondary amp, but running equalized (split) inputs from your head unit to each amplifier separately. This gives you so much more control - you can use one amp for the bass/sub-bass speakers, the other amp for the higher frequency speakers, and then do your crossover (or not) on the amps for each set of speakers independently. There is also a lot to be said for the separate gain control you will have for each set of speakers.

I have had very good results with a system not that much different from yours -- substitute 6" door speakers for your 6x9's in the rear deck, and it is much the same: dual PPI amps, MB-Quart speakers, single 10" subwoofer in the rear, etc.

Good luck, and let us know how it works out.

tanstaafl.

"There Ain't No Such Thing As A Free Lunch"