Flowery description here: http://www.spatialaudio.us/pagex3 - AMT driver, 12", 15" woofers - 85 lb each - Believe it's BEYMA TPL-150H with the back-plate popped off to make it dipole. - Woofers probably some modification of Eminence. - 15" driven by Hypex FA251 and has separate volume control (I just match sound level by ear). Controls 90 hz and lower. Sound - I've had PAP Voxativ 1.6 for a couple years and wanted more bass oomph and having powered 15" woofer just delivers that. - Just as detailed as the PAP Voxativ but way more tactile bass. Wife mentions sound is also more fuller and not "hi-fi jazz duty only" like the PAP's I had. - Can crank up Hypex to play wife's bassy music. - maybe the highs don't extend as much as Raal tweeters - FR seems very smooth(?) Thoughts on components - BiFrost, Yggdrasil, Saga OG, Goldpoint, Aegir single vs mono DACS: - Yggdrasil XLR >>> BiFrost XLR = Bifrost SE > Yggdrasil SE - BiFrost sounds a bit more liquid and very smoother compared to Yggdrasil. BF is also very fun to listen to and if I am single ended headphones setup, I would go for BF. Also soundstage is a bit different that Aegir: - Aegir mono sounded way more relaxed, dynamic and natural. Prefer XLR in all aspects. I did not detect the "sweetness" of single Aegir and think it's more of Yggdrasil single vs xlr difference. Saga vs Goldpoint: Goldpoint seems a bit more plankton. Overall, recommend the speakers and it just seems like an open window to music. Clean and fun. Doesn't do anything wrong I think. Probably consider biamping if you have OB speakers.