Synergistic Research HFT, High Frequency Transducer, Speaker-Room Upgrade (Set of 10) Every room has a sonic signature or sound. This sound goes beyond what can be measured with traditional acoustic measurement software. The sound of a room is literally made up of hundreds, if not thousands of resonators all reacting to the energy your stereo creates. HFT will "re-tune" spurious speaker cabinet and driver vibrations to more favorable frequencies. Dramatically improves low frequency extension / bass control. The simple application of an HFT to the right and left side of the speaker cabinet at woofer height (or centered on the side of the vertical frame for a panel speaker), with another HFT attached to the center of the wall behind the listening position at 5-6 feet above the floor, provides a powerful upgrade. These small transducers, strategically placed in the listening room make a great improvement to the sound and significantly improved all aspects of system performance.