woofer in 2.5 way affecting polar response

[thadman]

I'd like to incorporate multiple dipole midbass drivers in my design to alleviate excursion requirements, lower necessary baffle width, lower useable crossover point, and increase dynamics and efficiency.

I currently wish to use a WTMW alignment (RS225, NeoCD2.0, RS52, RS225) but wonder if a WWTMWW would be possible considering the low cost associated with the Dayton reference series. If the XO point for the first 2 (inner RS225s) would be in the 600-800hz range, how high should I cross the very top and bottom (outer RS225s). The CTC spacing of the outer midrange/midbasses would be <40", should I cross a little lower around 300hz to be safe?

Could I put a simple 6dB passive lpf on the outer RS225s at 300hz? The entire system will be active (DCX2496 with Crown amplifiers) and I don't want to use anymore amplifiers than I'm already required.

I also fancied the idea of using two RS52s. I could remove the faceplates and rear mount them to the front of the baffle and use a 1/2" or lower roundover to quasi-hornload them. In this way, I could move the CTC spacing from 5-1/8" (faceplate diameter) to 4-1/8" (cutout diameter) and maybe even narrower if I could remove the rear cup. The second RS52 would be used to lower the useable crossover point (800hz to 500-600hz) to make the required CTC spacing of the RS225s more acceptable, increase efficiency, and alleviate excursion requirements. A 6dB passive lpf would be added to the second RS52 to once again remove its influence from the radiated sound and power response. The CTC spacing between the ribbon and the second RS52 would be ~7" (~1900hz), so a 1200-1400hz XO could be used (lower/higher if required)

What effect do 2.5 ways have on power response if a 6dB passive lpf is used before the CTC spacing reaches 1 wavelength or 1/2 wavelength?