[CQ-Contest] CM-500 headset

Jim Brown k9yc at audiosystemsgroup.com
Wed Nov 21 16:12:34 EST 2018

Somehow this topic has split into two -- the headphones and the mic. :) 
That's a good thing, because both matter. My comments on noise rejection 
have, so far, addressed only the mic.

As to the headphones, I find them quite comfortable, and fairly good at 
rejecting other sounds, roughly equivalent to Sony MDR7506. My shack is 
pretty quiet except when the XYL comes through talking or banging the 
screen door. The talk QRMs me, the screen door triggers the VOX. It's 
quite loud. :)

The only operation I do in a multi is for our CQP and 7QP expeditions, 
and we've found the CM500 "good enough." I would certainly take the 
advice of guys with big multi operations like W3LPL. That said, after I 
visited his shack several years ago, I noted to Frank that it's hard 
surfaces made it an echo chamber that amplifies the noise, especially 
speech, and that putting sound absorbing panels to the walls would help 
a lot. This has long been standard practice in broadcast announce booths 
and production studios intended primarily for speech, and can make a 
HUGE difference as compared to hard surfaces.

The human voice is directional to the front and slightly above the 
mouth, so the absorption on wall surface directly in front of the 
operator is especially useful. Likewise for surfaces around noisy fans.

73, Jim K9YC

On 11/21/2018 11:43 AM, Larry wrote:
> Using headphones that block external sound becomes a trade off. 
> Effective noise cancelling headphones tend to be heavy and bulky. That's 
> fine for the casual user but become uncomfortable after a long period of 
> time. Contest users beware.

More information about the CQ-Contest mailing list