Solving Low Voice Volume on Peltor Comtacs with Baofeng Radios
If you’ve ever asked, “Why is my voice so low on my Peltor Comtacs when using a Baofeng radio?”—you’re not alone. This is one of the most common tech support questions we get. Here's the answer and how you can fix the issue to achieve seamless communication.
The Problem: Microphone Impedance Mismatch
The root cause lies in an impedance mismatch between your headset’s microphone and your radio. But what exactly is microphone impedance?
In tactical communications, microphone impedance refers to the electrical resistance of the microphone’s circuit. The lower the impedance, the better the microphone is at canceling background noise—but this also means the microphone must be positioned closer to your mouth for your voice to be picked up clearly.
Types of Microphone Impedance
Tactical headsets are typically designed with one of two types of microphone impedance:
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High Impedance (700–900 ohms): Common in civilian communications, allowing for normal-volume speech or whispers.
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Low Impedance (150–230 ohms): Designed for military use, optimized for noisy environments like Humvees or Blackhawks. Requires speaking forcefully into the mic.
Why This Matters
Civilian radios like the popular Baofeng UV-5R often require a high-impedance microphone. If you connect a low-impedance microphone (like those found on military surplus headsets) to a civilian radio, your voice will be extremely quiet, regardless of how loudly you speak.
The Fix: Solutions for Impedance Mismatch
Fortunately, you don’t need to toss your gear or settle for subpar communication. Here’s how to solve the issue:
1. Swap Your Microphone
Replacing the factory low-impedance microphone on your headset with a high-impedance microphone can provide an instant fix.
2. Use an Impedance-Matching Amplifier
If swapping the microphone isn’t an option, consider adding an impedance-matching inline amplifier.
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The Amp installs between your headset and Push-To-Talk (PTT) system to boost your microphone’s volume:
3. Upgrade to Amplified PTT Systems
We also offer PTT systems with built-in amplifiers for radios using the Kenwood/Baofeng 2-pin plug.
A Note on Wiring Standards
Microphone impedance is just one piece of the puzzle. The wiring of your headset’s mil-standard U174/Nexus TP-120 plug may not match your PTT’s pinout format. We’ll explore this issue and its solutions in an upcoming blog post.
Final Thoughts
Whether you’re operating in a noisy Humvee or running quiet civilian comms, understanding and addressing microphone impedance can dramatically improve your communication quality. Ready to upgrade your setup? Check out our range of high-impedance microphones and amplifiers to get started.