opinions, move to 3 way? - SQ quest!

Alright.  I'm now completely addicted to car audio again.  :-)  It has been a wonderful distraction and way to destress from the school year.  I've got just over a month before life gets crazy again.  Help me get closer to my search for car audio nirvana as the drive to / from school will be the highlight of my day come mid August.

I have ordered the Behringer ECM8000 mic, Rolls MP13 mic pre-amp, and the TrueRTA software.  I plan on using this to do the best I can to flatten things out via the semi-parametic eq the eclipse hu provides. 

I've dynamat xtreme matted the front doors, parts of the trunk, and under the rear seat.  I plan to buy another bulk kit and deaden some more steel.

So, my question is what should I do next to improve things even more?

My first idea is to move to a 3-way system.  My 6.5" drivers and tweeters are currently in the lower door location.  The imaging is just o.k.  There isn't much space, but I think I'd be able to fit a quart premium 4" midrange driver into a fiberglass kickpanel.  I'd then take the tweeter out of the 6.5" driver coax location, replace it w/ a phase plug, and mount the tweeter into the 4" driver in the kick. 

I'd use the crossovers on the deck to do the following:

Do you all feel like this would be a good 'next step'? 

Hmm, that's interesting.  That would certainly fill out my midbass and give the 6.5" drivers a narrower frequency range to handle.  I like it!  Anyone else, suggestions?  DYOhn, how large of an enclosure would you recommend for those Scan Speaks?

Not quite sure what I'll do about the amplification.  Are there any small 2-channel class D amps?  (For my dvc 2-ohm sub)

Oops, I put the wrong model number.  they're the 18w/8546 (kevlar cones.)  My kicks are about 0.7 cuft, I believe, but they could be smaller.  Very tight response, rated at 100 watts RMS.  I run mine off a McIntosh MCC 302 amp.

What kind of woofer is it?  If you want SQ, drive those 2-ohm voice coils in series for a 4-ohm load on the amplifier.

The woofer is an image dynamics IDQ-10 V.2  I run it in series currently from an Xtant A2002T.  I was thinking about using this amplifier for the midbass drivers and trying to find a more efficient small 2 channel class d to run the subwoofer.  

I can't get a mono amplifier to run at more than 1-ohm w/ a single dvc 2-ohm driver, correct?

Thanks again

(wow DYohn, sounds like you have an elite setup) 

A single DVC 2-ohm speaker can be wired for 1-ohm or for 4-ohms.

Your sub is rated at 250 watts RMS.  Run it at 4-ohms by connecting both voice coils in series.  There are many class D mono amps out there that will deliver 250 watts into 4-ohms.  I believe the Xtant 6.1 is rated at 300 watts into 4-ohms, which should be fine for this woofer if you want to stay with Xtant.