I visited the room twice, and the Mantas were in play the second time.
They were life-like and dynamic and conveyed the impression of being in the presence of live music. I heard no resonances. It seemed like I could hear every detail and nuance of the instrumental textures (which is probably not true given the age of my ears). When I closed my eyes they disappeared as the apparent sound source, and we were in a small and (IIRC correctly) untreated room.
I'm going to go out on a limb and say something I did not see coming: I think the Mantas plus their pair of matching subs had the most natural-sounding bass of any of the rooms. There was zero distracting resonance, only naturalness, in the midbass (in constrast with the vast majority of systems), presumably largely attributable to the cardioid loading. Here is the unexpected part: That characteristic held up all the way down; there was zero indication of a transition from one enclosure type in the upper bass to another in the lower bass; it was all "cut from the same cloth" to my ears. And the very lowest bass was rock-solid, neither overstated nor understated. I can only think of two other rooms where that was the case and the Mantas + subs were the most rock-solid at the very bottm end. Kudos to both the designer and the room setter-upper!
Thank you, since I wasn't there to assist with the setup myself, I was a bit anxious about how they were able to get the room to sound. It's actually the first time they've been presented without me to set them up. In March the Sarannas will be playing at a German show without me present, which will be equally scary.

That being said, both the Mantas and Sarannas are quite room friendly, so they're not the most difficult to set up. They sound very good in less than optimal conditions, and incredibly good in a proper room.
With regards to the bass and the transition - yes, that is one of the inherent qualities you get when it's all designed as a system. And both the speakers and subs are quite free of resonances, and all drivers are also well behaved in their pass band. The subwoofer drivers play in a quite linear fashion up to 1000hz, and the midbass driver in the Manta is also completely linear in the range it is playing.
I repeatedly get "Are the subs playing?" at shows, not because people feel bass is lacking, but rather that they can't perceive them as separate units, so it feels like it's all coming from the speakers.
I was looking forward to hearing your impressions, and I am very happy to hear that you liked them! Thank you for taking the time to stop by, and even a second time to ensure you got to hear them!
