All right GR Research peoples, I'm asking here about the PI diffusers here since so many of ya'll have OB-type speakers, and are also owners of PI Group products. I have all planar dipoles (ESL, Magnetic-Planar, Ribbon), and my new room is turning out to be very warm, non-reflective, and quiet. I love the quiet, but the lack of high-frequency energy in the room not so much. Even though my side walls are completely lined floor-to-ceiling with LP's and CD"s, the wall-to-wall carpet and ASC Tube Trap-loaded corners are making for an overly-dead room.
I am going to add sets of PI Audio Group Diffusers on the wall behind my speaker locations (5' from that wall), and I'm wondering which version of their diffusers will reflect and maintain the most midrange and high frequency reflections and energy coming at them from the rear of my speakers, plus whatever reflected energy comes their way. Would that be the AQD (vertical ribs and wells, which scatter sound horizontally only), or the ABB1dcs---aka Mr.T (double cuts, for vertical and horizontal scattering) diffusers? I've read some that say vertical ribs and wells make for more high frequency energy in a room, and I've also read from others the exact opposite. Opinions or experience welcomed!