I believe they are rated to the mid to high 30hz on their specs. In real world, in my room, they dont really every preside much in that space, and no other speaker that wasn’t full range claiming to play in the 30s didnt either. But I want to say, they do place waves in high 30s, but not and never with authority and presence. I’ve done simple RTA measurements of my room, and I always see a sharp dip starting at 50hz and below. The corners in my room will tend to muddy up anything that starts to exacerbate it in that region - I have a noise floor of about 37hz-ish... Thats just my room...which is why I have those RELs...If I remember correctly, I have my RELs at 8 clicks on the XO and 6 clicks on the gain (barely playing)...The Devilles do play clean from 63hz to 200hz. To my ears, when it hits 80hz with music, it sounds fast and articulate. But these are NOT wave moving monsters.
For what its worth, my listening space is in an open space concept shared with a kitchen to the back, foye to the right, and opens up to a dining area to the rear left of the listening position.
Some cornwalls or la scalas would have done nicely too, with maybe a smaller footprint considering I have two additional sub enclosure, but hey live and learn.