Sorry, haven't given you the full story. The jordans have a removable back panel so I can use them OB as well, which is what I'm doing at the moment. I have active LR4 crossover at 125Hz. The U frames are 12" deep
My audio buddy built u-frames with 2 Emince Beta 15 A in each frame. We measured FR with REW and he is getting bass more or less flat down to 30Hz without any EQ. He previously had magneplanar tympanis and acoustats in the same smallish room and I always found them a bit boomy. Be obviously he has some serious room gain around 30hz that just happens to offset perfectly the roll off of his u frame. Good luck rather than good management!
Bzfcocon, Vas as such may be irrelevant in OB, but since Vas is a direct function of stiffness (rather of compliance, which is reciprocal of stiffness), would Cms not be a factor to consider as far as how EASILY the driver would reach Xmax? For eg: if Cms for a given driver is quite high.. it might reach Xmax at much below required SPL.
Am i thinking on the right line?
I had a similar experience with a very large OB baffle.
Many members here are keen to be free of box sound and enhance the ambience and are pondering OBs. (See the discussion about ditching spatial localization in The Lounge forum.) But they are worried about the emanations from the rear of the drier sneaking around and annihilating the front emanations.
With an OB, you can install a driver with a low resonance and - unlike sealed boxes - it doesn't change. So you might be getting a boost in output at say, 25-35 Hz, just where you might like to hear it.
Hardly any "room gain" worth mentioning except in hermetically sealed cars. However, rooms have eigentones. But it depends on your seat location and the speaker location as to whether that will add or subtract at a given frequency. I think we notice the add-places more.
B.
@ wonderfulaudio: i would like to. However, i haven't found any application that will for android phone (which i can do lying down); and health doesn't much permit using a proper computer either standing or sitting.