Shure BLX14/SM31-H10 Wireless Fitness Headset System

The Shure BLX14/SM31-H10 is a complete wireless fitness headset system for instructors, trainers, presenters, and other active performers. It combines the BLX4 single-channel receiver, BLX1 bodypack transmitter, and SM31FH cardioid headworn microphone. The H10 version operates in the 542–572 MHz UHF band, so frequency authorization should be confirmed for the intended location before use.

This system is designed to keep a microphone in consistent position during movement while eliminating the cable between the wearer and the sound system. The SM31FH headset uses a secure wireframe fit and a flexible gooseneck for practical capsule positioning. Its cardioid pickup pattern is tailored for vocal use and helps focus on the person wearing the microphone.

The BLX wireless platform provides an analog UHF link with a specified line-of-sight working range of up to 300 feet. System audio response is specified at 50 Hz to 15 kHz, depending on the microphone used, while the included SM31FH microphone has a 45 Hz to 20 kHz response. A 100 dB A-weighted typical dynamic range and 0.5% typical total harmonic distortion support clear speech reinforcement in active environments.

The SM31FH is built for humid, high-motion applications such as group exercise and aerobics instruction. Its hydrophobic construction helps protect the microphone cartridge from moisture-related corrosion, and the included windscreen helps reduce breath, wind, and plosive noise. The lightweight, low-profile headset design is intended to remain comfortable through extended sessions.

The BLX4 receiver connects to a mixer, powered speaker, amplifier, or installed sound system through balanced XLR mic output or 1/4-inch instrument-level output. One-touch group scanning helps locate an available group and channel, while the BLX1 bodypack provides adjustable input gain. The system can be expanded with additional compatible BLX systems where local RF conditions permit, with up to 12 compatible systems per frequency band specified as region- and environment-dependent.

Key Features

• H10 UHF Band: Operates from 542 to 572 MHz; confirm local spectrum authorization before use.
• Complete Wireless System: Includes BLX4 receiver, BLX1 bodypack, and SM31FH fitness headset microphone.
• 300-Foot Working Range: Provides up to 91 m of line-of-sight wireless operating distance.
• Long Battery Life: BLX1 runs up to 14 hours on two AA alkaline batteries.
• Moisture-Resistant Headset: Hydrophobic microphone construction suits humid and active fitness environments.
• Flexible Audio Connections: BLX4 offers XLR mic and 1/4-inch instrument-level output connections.

Design & Installation

The BLX1 bodypack and BLX4 receiver use molded ABS housings for low weight and everyday portability. The SM31FH uses a lightweight wireframe headset, flexible gooseneck, TA4F connector, and moisture-repelling cartridge housing. Receiver front-panel indicators show audio activity and system-ready status, while its display shows the selected group and channel.

Connect the BLX4 receiver to power, then route its XLR or 1/4-inch output to a compatible mixer, amplifier, powered speaker, or audio system input. Use the receiver group scan, set the BLX1 to the matching group and channel, connect the SM31FH to the bodypack's 4-pin TA4 input, and adjust bodypack gain as needed. Keep the receiver positioned for a practical line of sight to the performer, and use the included clothing clip to manage the headset cable during active use.