High efficency monitors for ASL Waves?

You might consider the Omega Super 3's. Retail $530 a pair ballpark. 94 dB sensitivity, single-driver, honest 8 ohm load. Very nice at low and medium volume levels, but they do get a bit stressed if you really pound 'em. Long break-in time (typical of high efficiency full-range drivers). Disclaimer - I'm an Omega dealer.

Acoustic Energy Aegis Ones (or the newer EVO 1s). I've used this combo and it's very nice. The Aegis Ones claim 90db, the EVO ones claim 89db... since they're almost exactly the same, I'd guess they're both really more like 89db. They're mega-inexpensive also.

I'm currently using Wave-8s in my bedroom with Meadowlark Swallows (89db again I think), and this is a great combo also.

I've also used older Bozon Acoustics A60s, again 89db.

You don't need crazy efficiency, just good efficiency. 89db will do. Rear-ported monitors, corner-loaded can also help with bass, as always.