[CQ-Contest] CM-500 headset

Jim Brown k9yc at audiosystemsgroup.com
Wed Nov 21 13:37:30 EST 2018

On 11/20/2018 4:57 PM, Art Boyars wrote:
> Do you have any experience or other info about the CM500's effectiveness in
> blocking external sound?

Mics reject "external sound" two ways -- by virtue of directivity, and 
by inverse square law (that is, distance from the sound source). Most 
room noise we hear on the air is the result of mic gain being turned up 
much too high, combined with excessive compression. Good EQ settings 
that maximize talk power by cutting low frequencies and slightly 
emphasizing 2-3 kHz do a lot to reject room noise.

As near as I can tell, the mic in the CM500 is not directional. Nearly 
all directional mics are cardioids, which are essentially half-space 
mics. At best, they reject no more than 3-6 dB of room noise.

73, Jim K9YC

More information about the CQ-Contest mailing list