Electro-Voice ULM 21 - Cardioid Condenser Lavalier Microphone with TA4F Connector

Electro-Voice ULM 21 - Cardioid Condenser Lavalier Microphone with TA4F Connector

The Electro-Voice ULM 21 is an electret (back-electret) condenser lavalier microphone with a cardioid polar pattern, designed for unobtrusive, high-intelligibility speech pickup in professional environments. Its directivity helps to improve gain before feedback and reduce ambient noise pickup, making it especially suitable for theater, interviews, presentations, houses of worship, broadcast and PA systems . The miniature body and clip that attaches to the microphone itself facilitate correct positioning to maintain a cardioid pattern and consistent sound.

The ULM 21 features a 1.02 m (39 ft) shielded cable terminated in a TA4F connector , compatible with Electro-Voice/Telex bodypack transmitters. For wired applications, a TXA to XLR adapter can be used. A metal windscreen and RWS-013 mounting clip are included. Technically, it offers a frequency response of 80 Hz to 16 kHz , a sensitivity of −52 dB (re 1 V/Pa) , a self-noise of 29 dBA , a maximum SPL of 120 dB (1% THD), and a dynamic range of 91 dB , all of which support a clean, natural spoken word performance.

Main features

• Transducer: Electret condenser (back-electret) with cardioid pattern for greater off-axis rejection.
• Miniature and discreet format with clip on the body itself to maintain correct directivity.
• Response 80 Hz–16 kHz, sensitivity −52 dB (re 1 V/Pa), self-noise 29 dBA.
• High manageability : max SPL 120 dB (1% THD) and dynamic range 91 dB.
• Integrated 1.02m TA4F cable , EV/Telex beltpack ready; use with TXA for XLR connection.
• Included accessories : metal windscreen and RWS-013 clamp.
• Robust construction with black copper housing for intensive use.

User benefits

• Greater ambient control : The cardioid pattern reduces room leakage and improves speech intelligibility.
• Quick and reliable mounting : the body clip maintains the correct orientation of the microphone.
• Instant integration with EV/Telex wireless systems via TA4F; optional wired to XLR with the TXA adapter.
• Natural sound with a tuned response for voice and noise figures typical of a professional-quality microphone.
• Discretion on camera and stage thanks to its small size.

Use cases

• Theatrical performances and interviews where microphones must be used in a hidden location.
• Corporate and educational presentations requiring freedom of movement.
• Places of worship and live events with priority on clarity of message.
• Audiovisual production and spoken word streaming.

Frequently Asked Questions

• Is it a dynamic microphone? No. It's an electret condenser microphone and is powered from the bodypack (typical voltage 1.5 V) or via the TXA adapter when used wired.
• Can I connect it directly to an XLR input? Not directly; use the TXA adapter for proper power and matching.
• Does it work with other brands of TA4F beltpacks? It's designed for EV/Telex systems. Other brands may require rewiring or adapters depending on the pinout.

Description for projects

Cardioid electret condenser lavalier microphone (back-electret). Response 80 Hz–16 kHz; sensitivity −52 dB (re 1 V/Pa) @1 kHz; equivalent noise floor 29 dBA; signal-to-noise ratio 65 dB (at 1 Pa); max. SPL 120 dB (1 % THD); dynamic range 91 dB; output impedance 1 kΩ ± 20% @1 kHz; operating voltage 1.5 V; integrated cable 1.02 m; TA4F connector; capsule dimensions 23.6 × 10.5 mm; weight 5 g (without cable); color black; accessories: metal windscreen and RWS-013 clip.