Quality Electronic Products… Designed & Manufactured in the United States

VoiceMax   Transceiver Speech Processor

VoiceMax Revision B VoiceMax Revision B

- This Product Has Been Discontinued -

Why Do You Need a Speech Processor?

Two-way radio communication relies on the modulation content within the signal. Maintaining a high modulation level is crucial in providing the highest possible range from any transmitter operating on AM, FM, or SSB modes. Two-way radios use microphones that inherently change audio levels delivered to the transmitter. This causes transmitter modulation to fluctuate greatly depending on voice level and pitch. The average modulation of a typical voice signal is only about 40%. This low percentage applied to the transmitter, results in less than optimal transmission range.

Why Not Buy a Power Microphone?

Power microphones have an internal audio amplifier that amplifies all signals equally. That means that even the lowest background sounds are boosted significantly. This can be a major problem by creating a loud background distraction that competes with the voice signal.

What About Other Processors?

Other speech processors use a low cost audio clipping approach to achieve compression. While this method is economical for the manufacturer, clipping is undesirable and distorts the original signal. This makes your voice sound “fuzzy” on the air. What these types of processors gain in compression volume, they lose in voice intelligibility.

VoiceMax is Different... and There's Nothing on the Market Like it!

VoiceMax uses a sophisticated Automatic Gain Control circuit that installs inside your transceiver to hold the audio level constant, with typically less than 0.3% total harmonic distortion (THD). No "clipping" type processor can come close to this low distortion level. Whether you're whispering or shouting, VoiceMax holds your transceiver at 100% modulation allowing you to punch through heavy channel traffic without sacrificing voice clarity. VoiceMax incorporates a feature not offered on other processors. The adjustable noise gate allows the user to block unwanted ambient background sounds. This feature is especially helpful in mobile environments where wind and road noise can be an issue. VoiceMax works with your non-amplified dynamic microphone to give you tremendous audio punch without all the background noise associated with power microphones.

Complete Audio Processing for Non-Amplified Dynamic Microphones*
Automatic Gain Control Maintains Constant 100% Modulation Level
High 15:1 Compression Ratio
Adjustable Output Limiter Prevents Over Modulation
Adjustable Noise Gate Eliminates Ambient Noise
Extremely Low Total Harmonic Distortion
Modulation Indicator LED
Tiny Surface Mount Technology Mounts Inside Transceiver
Completely Shielded for High RF Immunity
Reverse Polarity Protected
No Batteries Necessary
Premium Electronic Components & Circuit Board
100% Production Tested
90 Day Limited Warranty
* Most stock microphones as well as Astatic #611L, Astatic #636L, Astatic #651L, Road King #RK56, and others.


PDFVoiceMax Specifications & Installation Instructions

Frequently Asked Questions...

Does VoiceMax Use Signal Clipping to Achieve Compression?

No, signal clipping causes distortion and produces audio that sounds “fuzzy”. VoiceMax uses a sophisticated automatic gain control circuit to maintain audio at a constant level with extremely low harmonic distortion.

Can I Install the VoiceMax Module Myself?

Yes, but for optimum results the installer should have access to an oscilloscope. The oscilloscope will be used in adjusting the output level of the VoiceMax module so that the transmitter will not over modulate.

Can I Use a Power or Condenser Microphone With VoiceMax?

No. Due to VoiceMax’s high gain we recommend that only non-amplified dynamic type microphones be used. Power and condenser microphones contain amplifiers that are generally incompatible with VoiceMax. There are many aftermarket microphones that work well with VoiceMax... such as Astatic 611L, Astatic 636L, Astatic 651, and others.

What is a Noise Gate ?

A noise gate is a feature that allows low-level sounds to be subdued. This is very useful in a mobile environment, where road noise can be a problem. VoiceMax’s noise gate threshold level is adjusted once during installation, based on user preference.

Does VoiceMax Require a Battery?

No, the power required for the VoiceMax module is extremely low, and is derived from inside the transceiver.

How Big is the VoiceMax Module?... And Will it Fit Inside My Radio?

The size of the VoiceMax module is 1.6” x 1.6” x 0.32” utilizing surface mount electronic technology. This small size should fit inside most transceivers.

How Will I Know the VoiceMax Module is Working?

VoiceMax has a modulation indicator LED that flashes in sync to audio applied to the transceiver’s microphone. This LED is viewed during the adjustment procedure, to make certain VoiceMax’s levels are set properly for your transceiver.

Should the VoiceMax Module be Operating All the Time?

Yes! The VoiceMax module was designed to be active whenever your transceiver is operating. This allows you to take advantage of VoiceMax’s performance boost every time you transmit.