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TM400
Wireless System for Test and Measurement


*System does not include microphone

  • Replaces long cable between calibrated microphone and test equipment
  • 24-bit, 88.2 kHz digital signal handling for compandor-free audio
  • 256 synthesized UHF frequencies for wide choice of tunings to avoid interference
  • Rugged all-metal construction
  • Receiver:
    • Low noise, robust RF front end
    • Balanced XLR audio output
    • SmartTuning™ with graphic display for easy selection of clear RF frequencies
  • Transmitter:
    • Converts microphones with XLR jacks to wireless operation
    • Selectable 5, 15, 48 Volt powering
    • 100 mW RF output power for long range

The TM400 system was designed to provide the ideal link between calibrated test microphones and measurement equipment such as SIM®, SIA SMAART Live®, TEF® or other systems. By using a radio link, long cables can be eliminated thus saving time and providing opportunities for additional measurements to increase accuracy. The microphone can even be moved around in the venue while the audience is present – something that is impossible with a cabled measurement microphone.

Lectrosonics Digital Hybrid Wireless™ (U.S. Patent Pending) uses a proprietary algorithm to encode the digital audio information into an analog format which can be transmitted in a robust manner over an analog FM wireless link. This combination offers the superb audio quality of a pure digital system and the outstanding operating range of the finest FM wireless systems. The digital audio chain eliminates compandor artifacts, and provides audio frequency response flat to 20 kHz. The RF link takes advantage of the spectral efficiency characteristics of an aggressively optimized FM radio system.

This digital/analog hybrid technique has some very beneficial properties. Because the information being transmitted is digitally encoded, useable dynamic range is much higher than a compandor can offer and there is no compandor in the audio signal to interfere with your measurements.

The TM400 system comes standard with the UH400TM transmitter, R400A receiver, and CCTM400 water-resistant case. However, the components can be ordered separately. Also, the R400A receiver can be ordered with a rack-mount front panel, at an additional cost.


January 2008
Product of the Month



Click to read ProAV's review of the TM400



PDFDownload the Quick Start Guide for this product in PDF format.
PDFDownload the Technical Data sheet for this product in PDF format.
PDFDownload the Instruction Manual for the UH400TM in PDF format.

PDFDownload the Instruction Manual for the R400A in PDF format.

Wireless Room Measurements, reprint from SynAudCon Newsletter, Volume 32, No. 4

Finding Clear Frequencies
Technical Note
(HTML)    (PDF)

Setting Compatibility Modes
Technical Note
(HTML)    (PDF)

Switch Setting vs
Frequency Charts


Freq Blocks vs
TV Channels Chart


Replacement Antennas and Remote Antenna Systems


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