I was digging through the closet and found a pair of Audax HT240ZO 10" (actually app. 9.5" dia) Aerogel drivers. These are pretty unique in that they are 95dB SPL at 2.83V with the Voice coils in parallel.  First this shouted at me - open baffle bass but the Qm/Qe factors don't look so awesome for that.

In a sealed/Aperiodic enclosure they will F3 at app. 60Hz in a fairly small enclosure - with the sensitivity and room gain this probably isn't too bad of an option for them.  AP vents damp the Z peak also, making an easier load for a tube amp w/o any components...if you like the sound of a sealed / ap

Vented they will go to app 40Hz in app. 2.3 cubic feet

In a ML-TQWT (mass loaded tapered quarter-wave tube) what I call a reverse-ported transmission line : )  they will go to 30 at the expense of extreme size.

Q is a touch high for a classical horn speak sadly, although somewhere someone did a "wicked" X horn with them and I have never been able to dig the project up.

Additionally, I nabbed these for 30.00 each a long time ago and so don't want to spend a ton of cash or time on them.

Spec sheet below along with average T/S measurements from SoundEasy. From the FR it appears to have a little bit of baffle step built in and probably good to 500hz or so. Any ideas?