m1 out of the box goes into compression all modes with any thing over 31 on the mic gain (31 out of 63 steps) out of the box
probably why they are default setting for 31 on the mic gain when you reboot the radio after doing the expansion to them
if you ran a m1 with a power mic or compression mic it would would horrible (especially on ssb) at 63 on the mic gain setting even with alc turned back to limit rf power as the compression is in the audio circuit not a result of over zealous alc adjustment
some people like magum some dont personally i am not a fan of the cp-1/sp-1/md-1 and glad they didnt get the factory to add that to it because it would of totally ruined it
the voyager 8800 which it was based off never had that compression in it and to me it was a nicer ssb radio
of course to a cber what seems "loud" is loud to them but to some one with a scope they would give this face
as magnumman (dave) said you dont run a ham rig ..yasesu /kenwood etc at full mic gain on a STOCK mic the alc would be tripping balls if you did ..in many cases this is the same for stock ssb cb radios however they dont have a alc meter (wish they would) and most cbers stare at their rf meters........
as for my optima i run a IC-251a mic (dont know the model of it) with a HC Heil insert and mike gain around 12 o'clock as the mic is a bit hotter than any stock icom mic (from the 1980's when icom used preamps in their mics) suits me but does not fix my accent
ps: i am not a heil fan boy however in this combo it works fantastic for me as i am not a loud speaker and have a monotone voice
With max rf power of 40w pep its just hitting the 2db compression on the monitorscope with voice peaks