Shure BLX14/SM31 Fitness Wireless Headworn Microphone System

Shure BLX® Wireless Systems provide a sound solution for freeing up your hands and making yourself mobile while speaking. Designed for demanding applications such as fitness instruction, the lightweight and secure wireless headset mic is protected with moisture-repellent construction. The bodypack transmitter can operate up to 300 feet away (line of sight) from the receiver.

Offering convenient hands-free use and secure placement, this system’s wireframe headset withstands constant movement. A cardioid condenser microphone, the headset mic features excellent off-axis rejection, and the included windscreen tames plosives as well as breathing sounds. The flexible gooseneck within the headset offers adjustment options to position the microphone for even further source isolation as the gym gets louder. Wireframe headset fits securely and is lightweight, so it does not jostle around or fatigue the wearer during high impact use. Hydrophobic construction in the headset protects the microphone from the corrosion damage that typically causes fitness instruction headsets to fail. The headset connects to the bodypack transmitter with a wire cable.

The Shure BLX14/PGA31 wireless microphone system communicates between the BLX4 receiver and the BLX1 bodypack transmitter. QuickScan frequency selection finds the best available frequency for the receiver and transmitter with just one touch at setup. On the receiver are LED indicators for gain levels, microprocessor-controlled internal antenna diversity, and other intuitive controls for simple setup and operation.

Paired to the receiver is the BLX1 bodypack transmitter. Many fitness instructors simply clip this to their waistbands, but the bodypack transmitter can also be worn from a belt. It is compact and lightweight enough to go unnoticed and not hinder any exercise movements. With a battery life of up to 14 hours and an LED indicator for low battery level, this wireless system operates through even long events. Functions such as group and channel selection and gain adjustment can be done right from the bodypack transmitter. The on/off switch is easily accessible and uses a toggle design, providing tactile indication when the transmitter is on.

Shure BLX14/SM31 Features

• Moisture-repelling construction protects microphone from humidity and sweat
• Simple setup and an intuitive interface for legendary audio performance
• Wireframe headset stays firmly in place during workouts

• BLX4 Wireless Receiver1
• BLX1 Bodypack Transmitter1
• SM31 Fitness Headset Microphone1
• PS24 Power Supply1
• Clothing Clip1
• Windscreen1
• Carrying Case1

• System
  • Working Range: 91 m (300 ft) Line of Sight
  • Audio Frequency Response: 50 to 15,000 Hz
  • Total Harmonic Distortion Ref. ±33 kHz deviation with 1 kHz tone: 0.5%, typical
  • Dynamic Range: 100 dB, A-weighted, typical
  • Operating Temperature: -18°C (0°F) to 57°C (135°F)
  • Polarity: Positive pressure on microphone diaphragm (or positive voltage applied to tip of WA302 phone plug) produces positive voltage on pin 2 (with respect to pin 3 of low-impedance output) and the tip of the high impedance 1/4-inch output.
• BLX1 Transmitter
  • Audio Input Level
  • max: -16 dBVmaximum
  • min (0 dB): +10 dBVmaximum
  • Gain Adjustment Range: 26 dB
  • Input Impedance: 1 MΩ
  • RF Transmitter Output: 10 mW, typical
  • Dimensions: 4.33 in. X 2.52 in. X 0.83 in. (110 mm X 64 mm X 21 mm) H x W x D
  • Weight: 2.6 oz. (75 g), without batteries
  • Housing: Molded ABS
  • Power Requirements: 2 LR6 AA batteries, 1.5 V, alkaline
  • Battery Life: up to 14 hours (alkaline)
• BLX4 Receiver
  • Output Impedance
  • XLR connector: 200 Ω
  • 6.35 mm (1/4") connector: 50 Ω
  • Audio Output Level Ref. ±33 kHz deviation with 1 kHz tone
  • XLR connector: –27 dBV (into 100 kΩ load)
  • 6.35 mm (1/4") connector: –13 dBV (into 100 kΩ load)
  • RF Sensitivity: -105 dBm for 12 dB SINAD, typical
  • Image Rejection: >50 dB, typical
  • Dimensions: 1.57 in. X 7.40 in. X 4.06in. (40 mm X 188 mm X 103 mm) H x W x D
  • Weight: 8.5 oz. (241 g)
  • Housing: Molded ABS
  • Power Requirements: 12–15 V DC @ 235 mA (BLX88, 320 mA), supplied by external power supply (tip positive)