I think I have something suitable with a removable baffle to play around with the next time I get time. It's a 2 cu ft enclosure with a removable baffle: somebody else's abandoned attempt at anelectric guitar setup. For the 15" RF, that bigger size will come in handy but would there a problem with using that bigger box to test RBH 10 inchers?
What size would you want for testing 4" and 6" drivers?
Quick update : After some ... maybe considerable consternation a cross of 60 Hz with bass being sent to both mains and sub was deemed soogin'. The sub sounds noticeably louder in reverse phase.
YPAO opted for reverse phase for the old sub as well but with this iteration, the difference is more noticeable. The gains were trimmed to make up for the gain the reverse phase caused. Then I trimmed them another couple of dbs after listening to some music. Maybe "BOTH" has an effect that normal rec'r test tones don't account for. Weird but whatev.
And now a real answer to Swerd's "turn off the sub" thing. These sub's of Mark's, well ... the boxes I build are anvils too but the bottom end is ... I've been sitting here for a bit trying to think of something that doesn't sound stupid ... not like anything I've heard. Turning the sub off while listening to Pat Benatar on vinyl was instantly disappointing. That special and new component it brings to most familiar music just stops being there, even with the Peerless 10s being sent the bass info as well.
I took the time to perch them up off the floor ... don't know what that does but it sounds marvelous. Night and day.