Here is a great article I found on the DX Engineering Blog. Tips for using your radio equalizer settings to improve your audio! Check it out at this link! FYI my Heil Pro 7 Headset came with recommended EQ settings based on your radio Yaesu/Icom etc etc.
Using the Right Tools
"Sorry, didn’t copy that, OM.” Our immediate reaction may be to repeat, repeat louder, crank the microphone gain, add more compression, or fire up the linear amplifier. Excessive gain and/or excessive processing accentuates background noises and can cause distortion. The amp makes these louder. Brute force methods can do more harm than good when they aren’t used properly—perhaps a future topic for OnAllBands.
This is where the equalizer can be a subtle yet effective solution for making your voice stand out. Human speech range goes from about 100 Hz to 8 kHz, but only the energy between about 400 Hz and 4 kHz actually contributes to speech intelligibility. Content below 400 Hz brings out the James Earl Jones voice, but it also contains breath pops, room noise, mic handling noise, wind noise, and reverberation. It contributes nothing to communications."