I'm definitely leaning to the 8's. Thanks for the help, any suggestions for good 8's other than the CDT's on sale. I'd use the MB quarts as they're even cheaper( $50.00/each at woofersetc..), but they seem to be sealed applications only.

 

Polk MM840
or
JBL GTO804

Great subs for the money.

 

Arc Audio ARC 8". My understanding is that Arc Audio ordered them from Image Dynamics as a black version of the IDQ. Very similar. Not EXACTLY the same but very close.

TREO SSi 8" but expensive.

 

As per Matt at ID...ARC is similiar to the ID8. The IDQ is on another level.

....both Polk and JBL are less expensive.

 

I have two JL w3 - I think 4 would be pretty sweet.

As for a 15 playing lower than 4 eights and less punchy, etc. I always thought that once your surface area of your subs is identical between two different setups, that there is no difference...

 

How low a driver can play is relative to it's specs, not how many you have or it's cone area....