Dear Normis,
I just double checked, my 2.4GHz units are not Lite, they are "SXT2" (SXTG-2HnD) they have a speaker/buzzer and beep on boot.
However my other 5GHz units are as follows:
The older units are "SXT Lite5" (SXT 5nD r2) , they have speaker/buzzer and I can hear beeps on boot.
The newer "SXT Lite5 ac" (SXT 5HacD 2n r2) do not beep, could be as you mentioned does not have buzzer. That is a pity
Sorry for the confusion.
Thanks