At this point in time, I doubt I have anything that will reproduce 15HZ or anything below 20 for that matter, but the wish to capture these frequencies is really for some future when I may have a super-duper system that rattles the walls, as well as for making the recordings to be released in some way for the benefit of others who may have systems that can reproduce it.
I'm going to order a couple of the Behringer ECM8000's and I may experiment with subkick-style speaker/microphones. I have 8 inputs on my Mixpre10 so in addition to the four required for the? Ambi-alice, I have a few channels to play around with.
Mark Day