DMTH4

Advanced Digital Telephone Hybrid
Connects phone lines, video codecs, and audio sources directly into DM Series processor systems.

Built-In 3x24 Digital Matrix Mixer
Treats all sources as part of the sound system with full DSP on every input and output.

Dual Echo Cancellation Systems
Includes acoustic echo cancellers (126ms) and line echo cancellers (30ms) for clear, echo-free communication.

Comprehensive Signal Processing
Each input and output includes 6 filters and dynamic processing (compression/limiting).

Automatic Mixing with AutoSkew™
Proportional gain mixing algorithm ensures clean, balanced audio across multiple microphones.

Daisy-Chain and Expandable
Includes digital I/O for stacking and connecting to other LecNet2 devices in large systems.

Versatile Control Options
Control via USB, RS-232, or LecNet2 software; supports third-party integration.

Macro Support for Automation
Store up to 128 macros with 64 commands each for powerful system control.

Full Integration with DM Series
Works seamlessly with DM matrix processors, scaling from small rooms to complex audio environments.

Ready for Installation
Includes cables, connectors, software, and accessories for immediate deployment in conferencing and telepresence setups.

General Specifications
Device Type: Digital Telephone Hybrid and Matrix Processor
Model: Lectrosonics DMTH4
Matrix Architecture: 3 Inputs / 24 Outputs
Integration: Full integration with DM Series processors
Auto Mixing: Proportional gain with AutoSkew™ (US Patent 5,414,776)
Acoustic Echo Cancellers: 2 (126 ms tail time)
Line Echo Canceller: 1 (30 ms tail time)
Signal Processing: 6 filters + compressor per input, 6 filters + compressor/limiter per output
Phantom Power: No
Macro Support: 128 Macros (up to 64 commands each, 115 characters per command)
Remote Management: USB and RS-232 interfaces
Control Compatibility: Simultaneous LecNet2 and third-party control
Daisy-Chaining: Supported via Digital I/O ports (RJ-45)
Balanced Audio Path: Yes (no pin 1 issues)

Audio Performance
Frequency Response: 20 Hz – 20 kHz
Dynamic Range (Input): 102 dB (unweighted)
Dynamic Range (Output): 105 dB (unweighted)
THD+N: 0.02% (nominal input level)
Crosstalk (Line Level): –103 dB
Crosstalk (Mic Level): –101 dB
Sample Rate: 48 kHz

Input/Output
Inputs: 3 x 5-pin Phoenix, 2 x RJ-11 (telephone), 6 x RJ-45 (expansion)
Outputs: 24 x 5-pin Phoenix
Logic I/O: 1 x DB-25
Control Ports: 1 x USB, 1 x 1/8" TRS stereo mini serial
Input Impedance: 10 kΩ
Output Impedance: 450 Ω (0 dB attenuation), 5 Ω (–40 dB attenuation)
Maximum Input Level: +20 dBu
Maximum Output Level: +20 dBu

Physical Specifications
Dimensions (W x D x H): 19 x 7.5 x 1.7 in (483 x 191 x 43 mm)
Weight: 3.5 lbs (1.6 kg)
Package Weight: 9.25 lbs
Box Dimensions: 24.2 x 14.4 x 6.4 in

Included Accessories
1 x Power Cord (Part #21499)
1 x 25-pin Connector (Part #21558)
2 x 5-position Plug (Part #21580)
1 x LecNet Cable – Black (Part #21529-1)
1 x LecNet Cable – Red (Part #21710-1)
2 x Cat5 Cable (Part #21716)
1 x USB Cable (Part #21713)
1 x Telephone Cable (Part #21753)
1 x Adjustment Tool (Part #35679)
1 x DNT Software CD
1 x Manual