H Forest,

Joanne's comments (in a previous posting) should also be helpful to you. I
receive very good audio reports with a Heil GoldLine/HC5 mic plugged into
the 756Pro2 MIC socket, and with the following Pro2 settings:

Mic Gain at 50%
COMP set for 3 to 5 dB compression (max.) on voice peaks
Treble: +3
Bass: -2
COMP ON MID (compression on, transmitted occupied bandwidth 2.5 kHz)

George W5YR has written excellent articles on the 756Pro2's transmitted
occupied bandwidth and monitor.

http://www.qsl.net/ab4oj/icom/occbw/main.html

http://www.qsl.net/ab4oj/icom/occbw/mon.html

For optimum articulation, the MID or NAR settings work best. As Joanne
mentioned, transmitting excessive low-end energy wastes transmitter power
without contributing to articulation (ability of the distant station to
copy). For less-than-optimum band conditions, the HC5 element with MID or
NAR, or the HC4 with NAR for extreme cases, "gets through" very effectively.
The GoldLine's wide-range element with the WIDE setting is great for
"smooth", but clean and crisp rag-chew audio. And the occupied bandwidth
never exceeds 2.9 kHz at -6 dB.

Cheers for now, 73,
Adam VA7OJ/AB4OJ