I was looking at the profiles here :
I entered all the parameters for each profile into a spreadsheet so I could easily compare them.
I can’t discern any difference between profiles 14 and 15. The only difference I can tell is that profile 15 contains the additional verbage 4CH(ear clips) and 4 channels ([SIZE=13px]2 forehead+2 ear clips) rather than just 4CH and 4 channels. This does not appear to make any difference in the parameters.