Can anyone with the SR71 (Blackhole 5) Treatment please comment on its sonic benefit.
Thanks,
John 
Hi John,
You may find the information from the BH5 literature, interesting:
Black Hole 5 is a complex multi-layer material system that combines three key functions; damping, isolation, and absorption. The overall thickness of Black Hole 5 is 1-3/8", but. Optimized for use in speaker enclosures, as well as any other acoustical dampening installations. All layers are laminated together using a special thermal process, without the use of adhesives or solvents.
Layer 1 - High loss vibration damping material (same as the Black Hole Pad), deadens resonance from the cabinet. It is very strongly bonded to the wall with PSA film for optimum performance.
Layer 2 - Polyester urethane flexible open cell foam ¼ in. thick. Thanks to its special vibration-isolation characteristics, it de-couples the vibrating structure (the cabinet wall) from the rest of the damping system, thus optimizing its performance.
Layer 3 - Barrier septum 1/8 in. thick. Made of limp flexible vinyl copolymer loaded with non-lead inorganic fillers, it acts literally as a dead wall, thus isolating the vibrations in the walls of your cabinet and the vibrations created inside the enclosure from each other.
Layer 4 - Polyester urethane foam 1 in. thick, structurally optimized for acoustical dampening, (specific permeability, density, stiffness, pore size and shape). It is highly effective at "soaking-up" maximum sound energy with minimum thickness.
Layer 5 - Thin diamond pattern embossing, densified with polyurethane film surface. This unique surface layer improves dramatically the performance of the whole acoustical system, especially the lower mid-bass frequencies, (very sensitive range where simple acoustical foam becomes mostly ineffective).
