Check the listing for details. Primacoustic RX5 - HF Compact Recoil Stabilizer, Horizontal Fire. Condition: New. Listed at 144.99 USD. The Primacoustic RX5-HF Compact Recoil Stabilizer is a unique mounting device for your audio speakers that eliminates disruptive resonant coupling from the loudspeaker to the stand. In addition, the RX5 Recoil Stabilizer provides a stable base that reduces recoil from the forward energy of your loudspeaker. Made from three basic components, the Recoil Stabilizer is essentially a platform for the loudspeaker that features a high-density urethane base that isolates the speaker from the shelf, monitor-bridge or stand. This effectively decouples the loudspeaker to eliminate vibration-borne resonance to the substructure. A heavy laser-cut steel plate is added and sandwiched between the isolation layer and a no-slip neoprene top.