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Zaxcom ZMT4 Transmitter

Zaxcom ZMT4 Transmitter

Design Matters

The ZMT4 has taken digital recording wireless to the next level with 30% better power consumption, NeverClip™ in all modes, and power for all microphones – from a 5V lavalier to a 48V phantom powered mic – and a new ultra-low noise preamp. Deliver pristine audio quality with our ZMT4, an incredibly small, lightweight, talent-friendly transmitter ideal for sound professionals. Weighing only 2.2oz (62g), the ZMT4 is constructed from a high-strength, impact-resistant nylon polymer casing with rounded edges and machined metal that’s cool to the touch.

Microphone Connectivity

The ZMT4 has a wide range of power to cover nearly any professional analog microphone – 5V lavalier mics as well as condenser, balanced dynamic or ribbon microphones running at 12, 24, 36 or 48V. Perfect for boom pole operation, the ZMT4 can be positioned at the top of a boom pole directly behind the microphone instead of near the bottom. By removing the internal or external cable, operators can eliminate cable noise that can affect the audio track. Boom microphone connectivity is via a 3-pin balanced LEMO.

Encrypted Audio

The ZMT4 transmits using 100% digital modulation allowing audio to be fully encrypted. Digital encryption is the only way to keep all audio transmission private. A digital transmission also provides audio quality superior to analog systems.

Adaptive Antenna Optimization

This new feature in the ZMT4 improves radiation of the bodypack’s antenna when it’s placed in contact or near the human body. Normally, putting a bodypack on talent decreases transmission range because the body absorbs some of the signal. With adaptive antenna optimization, the external antenna is actively matched to its condition to optimize radiation and minimize distortion, keeping the signal at its best.

Microphone Preamp

The ZMT4 features an all-new preamp design. The noise content of the preamp and A-D combination now utilizes NeverClip™ with both lav and balanced boom mics, making the environment and self-noise of the microphone the dominant noise components.


NeverClip™ is available in all modes on the ZMT4. It works by utilizing two A-D converters to extend the dynamic range of the transmitter to 136 dB, so there’s never any limiter distortion.

Internal Recording

Audio is simultaneously transmitted and recorded to a removable microSD card using the highly reliable MARF (Mobile Audio Recording Format) which eliminates file corruption common to recordings due to a dead battery or early card removal.


ZMT4 is equipped with ZaxNet™, a long-range remote-control system allowing the user to change the frequency, pre-amp gain, sleep mode, and place the internal recorder in record, playback, and stop modes – all without ever needing to disturb talent.


To extend battery life, PowerRoll™ adjusts the ZMT4’s power level to 50mW when the audio received from it is being recorded by a ZaxNet™ compatible recorder. When the transmitter audio isn’t being recorded the power is automatically reduced to 10mW.

Modulation Choices For Your Environment

The range will always vary depending on your environment, but you’ve got choices to optimize transmission for peak performance. Zaxcom High Density modulation (ZHD) increases the number of available channels from 4 to 9 for every 1 MHz of spectrum space, perfect for reflective environments like busy city streets. XR gives you the maximum distance in less dense / more controlled spaces.


The ZMT4 has up to 30% better battery life than its predecessor. A single NP-50 battery provides up to 6 hours of runtime with a lavalier running at 5v and up to 4.5 hours of runtime while using a 12-48v boom microphone.

      • RF Modulation: Proprietary Digital Method
      • ZMT4.5 RF Frequency Range: 512 - 608 MHz
      • ZMT4.6 RF Frequency Range: 578 - 698 MHz
      • RF Frequency Step: 100 KHz
      • RF Bandwidth in ZHD96 Mode: 100 KHz
      • RF Bandwidth in XR Mode: 200 KHz
      • Channel Separation in ZHD96 Mode: as close as 200 KHz
      • Channel Separation in XR Mode: 400 KHz
      • Antenna Connector: 50 Ω SSMA Female
      • Emission Designator: 180 KV2E, 100 KV2E
      • FCC Part: 74.861
      • Dynamic Range: 136 dB
      • Distortion: 0.01%
      • Frequency Response: Mode 0: 20 Hz to 16 kHz / T & M Mode 0.2 Hz to 16 kHz
      • High Pass Filter: Off or 70 to 220 Hz, Steps: 10 (6dB Per Octave)
      • Unbalanced Lavaliere Mic Power: 5.0v @ 10mA max
      • Balanced Mic Power: 12v @ 25mA max
      • Balanced Mic Power: 24v @ 10mA max
      • Balanced Mic Power: 36v @ 10mA max
      • Balanced Mic Power: 45v @ 10mA max
      • Mic Connector: 3-Pin Micro LEMO
      • Mic Configuration: Balanced (3-wire) / Unbalanced (2-wire)
      • Input Range: -60 to -30 dBu
      • Mic Impedance: 3.4 k Ω (680 Ω with 12v power mode)
      • ADC Bit-Depth: 32 Bits
      • ADC Sampling-Rate: 32 kHz
      • Clock Accuracy: 1.54 PPM (1 Frame in 6 Hours)
      • Timecode Type: SMPTE
      • Timecode Frame-Rates: 23.98, 24, 25, 29.97NDF, 29.97DF, 30NDF, 30DF
      • Media: MicroSD Card (Flash Memory)
      • File Format: .ZAX / Converts to BWAV or MP3
      • RF Frequency Range: 2.403 to 2.475 GHz
      • RF Modulation: Digital Spread Spectrum
      • RF Frequency Step: 0.001 GHz (1 MHz)
      • RF Bandwidth: 1 MHz
      • Channel Separation: 2 MHz
      • Sensitivity: -96 dBm
      • Weight: 2.2 oz / 62 grams with Battery
      • Dimensions (H x W x D): 2.2″ x 1.6″ x .55″ / 55.8mm x 40.6mm x 14mm
      • Display: Graphic OLED
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