Listening chair suck-out

Oh brother. I've been placing acoustic panels here and there in my room in order to deal with various reflection-based frequency anomolies, with remarkable success for the most pary. I use an SPL propped up with a tripod to the listening position, which happens to be in a comfy stuffed leather chair The chair eats 165Hz! About 25dB of it, to boot (from about 75dB down to 50dB). If I put the mic at the listening position sans chair, there is no suck-out at all. It is definitely the chair. Anyone have tips for building a marble throne?