Shure BLX14/SM31-J11 UHF Wireless Fitness Microphone

The Shure BLX14/SM31-J11 is a complete UHF wireless microphone system engineered specifically for fitness instruction and active performance environments. At its core is the SM31FH fitness headset condenser microphone, a lightweight and moisture-resistant headset that stays securely in place during high-energy movement. The headset connects to the BLX1 bodypack transmitter, which clips to a waistband or belt and delivers up to 14 hours of transmission on two standard AA batteries—enough to cover a full day of back-to-back classes without a battery swap.

The BLX4 single-channel receiver provides stable UHF signal reception with an operating range of up to 300 feet, giving instructors the freedom to move throughout large studios, gyms, or outdoor spaces. Setup is straightforward: sync the transmitter and receiver, clip on the headset, and you're ready to go. The system supports up to 12 simultaneous channels per frequency band, making it practical for facilities with multiple instructors working in the same building. The included windscreen, clothing clip, and belt clip round out a well-considered package. One important note: the J11 frequency designation is region-specific, so prospective buyers should verify compatibility with their location using Shure's Wireless Frequency Finder before purchasing.