PAP Trio 15 OB with minidsp2x4hd

I Am depositing this as a thread per suggestion.

I own a pair of PAP Trio 15’s with the W81808 fullrange, and have been extensively investigating them for over a year. Have come to some unusual conclusions and look forward to comparing with others.

I have two 15” neo woofers in W-W-FR configuration. They are crossed at 120hz 48db L-R and are driven from a minidsp2x4 hd using one dsp channel with a mixed L+R channel.
Spaced 4’ from back and side wall and separated by 7’.

The FR has a vertical baffle extension to support its ability to deliver down to 120hz. That driver is weak below about 225hz in OB, and I am convinced a new baffle shape would help.

I use FIR filters exclusively on the FR, getting phase as close to zero as possible. I wish I had more FIR taps. With FIR filters, I have almost entirely eliminated the scratchiest of the tangband at high volumes. More work to do here.

I would love to hear from any OB and minidsp owners on how they tame their fullrange.

I use reconditioned amps...bas driven by a Hafler 220, fullrange by a Hafler xl.

There are a couple of fundamental issues with the PAP trio 15...

a) fullrange is not physically aligned with bass drivers, there’s a 5 cm time delay due to this.
b) fullrange baffles are wider than they should be for best image, and not wide enough to support low crossover frequency easily
c) frame resonances aren’t isolated from fullrange

...but that said, the bass resolution is astoundingly great. And the image with FIR is convincing!

There are several thing I have yet to try that I expect would further improve things...

- instead of a 21” wide FR baffle I want to build one with minimal front face, curving back approx 30 degrees side and top to shift the baffle loss to a lower frequency and improve image.

- adding a vertical dome tweeter with dispersion baffle to create omni above 5khz, turning the tangband into a midrange. Use dsp to linearize phase.

- make an h frame for the lower 2 woofers and use a spare L+R dsp channel to cross it in below 80 hz...or instead try that dsp channel on a sealed sub to extend lowest bass.

- make bass baffles out of something really heavy, like quartz countertop material.