Inertial sensing in Butterfly Vario, TE vs Airmass indicators

Thanks again,

I use both speakers when flying my ASH25. On my last flight I had the rear seat passenger turn his volume completely down and attempted to set the dead band on my unit. Changing the numbers plus or minus up to 100 seemed to make no difference. Do I need to disable one of the speakers or perhaps set it from the back seat? Does increasing positive or negative numbers increase the wide band?

Dale