Lectrosonics TM400 & TM400A

Note that there are two generations of this kit. TM400 is the older version and has an analog settings interface. TM400A is the current version and has a digital settings interface. If ordered as an actual kit, the hardware comes in a Pelican case. The parts can also be ordered separately. If you are purchasing for use in the EU, I suggest you contact Lectrosonics for guidance in selecting the right hardware as RF regulations are different than in the USA.

Lectrosonics TM400 webpage
TM400 frequency Table Switch Settings key
Tech-Notes – Finding clear frequencies
Tech-Notes – Setting compatibility modes digital hybrid wireless TX
Wireless Room Measurement article PDF – Syn-Aud-Con Newsletter
Vol. 32 No. 4

Live Sound Design Online – Product of the Month 2008
TM400 Review by James Elizondo
TM400 SVC Online review
TM400 University of Arizona / Pro Sound aritcle 2007

Rational Acoustics Forum thread about TM400 and multichannel receiver
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.

 Manufactured in the USA to exacting standards, the TM-400 is ruggedly built and engineered to deliver years of reliable service, even in the most demanding production environments.

 The complete kit includes the HM transmitter, R400A receiver, XLR pin swap adapter (required to phantom power some microphones) and foam-fitted, water-resistant hard case.

Here is a photo of the TM400 transmitter with an Earthworks M30 & the necessary XLR pin swap barrel.

Earthworks M30 & TM400 with barrel

Key Features:

• 24-bit, 88.2 kHz digital signal handling for compandor-free audio
• 256 synthesized UHF frequencies for wide choice of tunings
• Rugged all-metal construction

• Low noise, robust RF front end
• Balanced XLR audio output
• SmartTuning™ with graphic display for easy selection of clear RF frequencies

• Converts microphones with XLR jacks to wireless operation
• Selectable 5, 15, 48 Volt powering
• 100 mW RF output power for long range

Operating Frequencies (MHz):
• Block 21: 537.600 – 563.100*
• Block 22: 563.200 – 588.700*
• Block 23: 588.800 – 607.900, 614.100 – 614.300*
• Block 24: 614.400 – 639.900*
• Block 25: 640.000 – 665.500*
• Block 26: 665.600 – 691.100*
• Block 27: 691.200 – 716.700*
• Block 28: 716.800 – 742.300
• Block 29: 742.400 – 767.900


If you want to see some examples of how tough Lectrosonics RF gear is, visit this website:

Gnarly Wireless