The floor will flex the least near outside walls, particularly in a corner of 2 outside walls. Unfortunately, this si where airborne sounds will be reinforced the most. I'd say try locating it close to a corner and see what happens.
turntable feedback
I have suspended hardwood floors in my house and just cannot listen to my turntable at much volume especially with the subwoofer on. The turntable is on a dedicated stand. I have asked local dealers for advice but to no avail. there is no logical place in my room for a wall mounted shelf so that is out of the question. I love the sound of vinyl and have a huge collection that is being ignored because of this horrible problem "Im going crazy pease help!!!"