AirBlade Speaker - wow

The Airblades are a variation of the Heil AMT (Air Motion Transformer) design.  In the '70's I owned a pair of ESS AMT-1B speakers that used a Heil AMT speaker as the midrange and tweeter.  It also had a 12" woofer and 12" passive radiator. Check out the below link. I paid $700 back in the '70's. The Heil AMT sounded great. The cabinet for the woofer and radiator was the weak link.

@sc2  I owned the ESS AMT-1B speakers for a long time as I used them in a 2nd home up until about 4 years ago when I sold them.  I re-foamed the 12" woofers a couple times and replaced the 12" radiators.  Always loved the sound of the Heil AMT.  You're right, the Heil AMT's are fast so you'd want a fast sub like a REL. The crossover frequency of the AMT 1B speakers is 800Hz, so you'd need a sub capable of good response a bit beyond 800 Hz and possibly a crossover assuming you can't feed the Heil AMT's full frequency. You can find Heil AMT's in good shape on eBay for under $500, so for someone with a REL or other fast sub, they could prototype a rig for about $600 including purchasing the Heil AMT's and a DIY crossover. If the results are good, then add a 2nd sub and xover and you're all set.