I have no experience specifically with Definitive Technology speakers but I have designed and manufactured bipolar loudspeakers. Set up correctly, bipolars can convey rich timbre and do a good job of disappearing as the apparent sound source. They arguably can do a better job of presenting the acoustic signature of the recording venue, as opposed to the "small room signature" of the playback room, but adequate distance from the wall behind them matters a lot.
I suggest locating the speakers at least five feet out in front of the wall if possible, and three feet minimum. If you have to place them within three feet of the front wall, I suggest diffusing the output of the rear-firing drivers.
I do not suggest absorbing the output of the rear-firing drivers because they are there to make a spectrally-correct contribution to the reverberant field. Absorption will remove the short wavelengths (high frequencies) but have progressively less effect as the wavelengths get longer (as the frequencies become lower). So absorption can end up ruining the spectral balance of that reflected energy, which correspondingly degrades the timbre of the system.
Duke
I suggest locating the speakers at least five feet out in front of the wall if possible, and three feet minimum. If you have to place them within three feet of the front wall, I suggest diffusing the output of the rear-firing drivers.
I do not suggest absorbing the output of the rear-firing drivers because they are there to make a spectrally-correct contribution to the reverberant field. Absorption will remove the short wavelengths (high frequencies) but have progressively less effect as the wavelengths get longer (as the frequencies become lower). So absorption can end up ruining the spectral balance of that reflected energy, which correspondingly degrades the timbre of the system.
Duke