Thiel Owners

Lemming - what's your ceiling height?Are all drivers working? Finger on the cone test.You can check driver polarity with a 6 volt lantern battery. Best test is battery plus to wire at the disconnected cable at the power amp. All drivers should move out into the room.  

that's amp end of the disconnected RED wire.

My ceiling is 10’ high. 
All speakers are working. As for the battery test I’m a little unclear as to your directions

i could reverse one speaker connections to see if the bass improves, but assuming for the moment the highs are wired correctly and the bass was wired backwards my highs will end up out of phase, correct?

i would need to flip the bass driver wiring I suppose. 

Nice room dimensions.
Don't switch anything until you know if there is a polarity problem.Disconnect the cables at the power amp. Connect 6V battery - minus to black wire and touch + plus to red wire. The coax and woofer should both move out. Repeat on other speaker.

Your symptoms could be created by 1 woofer being polarity reversed.

last_lemming
Nice! system. Interesting combination of Cardas/PAD cabling. Agree with Tom's assessment and suggested testing polarity. Does the B.A.T. pre-amp reverse polarity? The CS 2.4 loudspeaker is balanced Bass to Treble, Treble to Bass without any mid-bass fall out.  Hope the culprit is diagnosed soon. Good to see you again.

Happy Listening!