I believe that the switch on the back of the head (or where ever it lives) changes the output level between speaker and headphone level and does not switch the speaker in and out. It may mute the speaker when there is something plugged in, I think.
There may be another headphone level out provided in the RJ-45 8 pin jack for the mike like Icom had on the IC-7100. Memory fails at this time, however.
