Good points Norman. My speakers are equipped with spikes that rest on an 18-inch slab of concrete and so vibrations transmitted through the floor are not my main concern. Rather it is the air-borne transmitted vibrations that needed to be addressed and the HFTs seem to have accomplished this objective.

Well, my speakers are spike coupled and the floor that is beneath them is 6" thick concrete with 3/4" rebar reinforcement in a 25' X 23' room. The speakers resonate as the manufacturer intended, within itself rather than through the floor plus they were designed to minimize floor bounce. SR has done a fabulous job in maximizing the sound waves to focus the soundstage throughout the room in an organized manner. My room needed a lot of help and SR provided it at a reasonable cost, with quite explicit instructions on HFT placements, despite the lack of scientific/engineering test results. I had all sorts of room sound devices to break, block, absorb and isolate sound wave energy (various reflective/aborptive panelling, basetraps, corner traps, etc.)-all together they kept confounding me and were driving me mad. I removed them all except for the Hallographs which worked on my speakers direct wave propagation while the SR HFTs worked on the reflections.

I installed Levels 1 through 4 and a pair of speaker kits of HFTs (32 HFTs in a room 25' X 23' X 12.5"). I already owned two pair of the marvelous Shakti Hallographs for imaging my big 5 way speakers (Legacy Focus). Upon installing the recommended set-up by SR (except for the anomaly where I cannot put an HFT of any type on the face of my speakers at the mids/tweeter/super-tweeter), the suggested placement was nearly perfect. I removed all the other paneling and damping in my live room . While music is playing, the slap echo ceases to be. Clapping ones hands is met with a sharp, short slap sound instead of the ringing echo. The HFT system works great with the Hallographs and allowed me to open them up more in the mid-room location which created wall to wall sound with the appropriate music. The depth greatly improved and pianos sound lifesize between the speakers, even in most mono recordings. Since I consider the room acoustics 50% of the sound component, you can imagine how happy I am with my dedicated music room now with the addition of the SR HFT system. The movement of the HFT 2.0s on the speaker sides just 1/4" up and down made a significant difference in bass and mid-range warmth (even in this good sized room). This system is essential for rooms with acoustic problems.

As to the Blackbox, I heard that 90% of the audiophiles who audition it keep it. In my case, while it created a deeper soundstage, it also collapsed the sound between the speakers and cut-off the highs above 8Khz. I tried it all the way from the wall to the middle of the room, side to side and back to front. It just didn't sound right for most music. Your mileage may vary in your room and equipment, especially if you have a bright sounding system or a distorting one (it smooths out the sound).