Visc=... (Optional) Reflex enclosure. Factor to switch off calculation of vent-damping due to
viscosity or to modify its strength.
Off: Visc = 0
Default: Visc = 1
Decrease of damping: Visc = 0 ... 1
Increase of damping: Visc > 1
There are referances all the way through the manuel on visc if you do a key word search on the manuel it will highlight them all for you.
As I understand it, if you specify baffle height and width in the "Radiator" section, Akabak starts modelling an enclosure in 4pi with baffle-step. Then you can use "Reflector" to add reflecting boundaries such as the floor.
 Baffle-step is a big deal. It can tilt your response by 3dB/octave and drop the sensitivity of drivers by up to 6dB compared to the half-space sensitivity usually quoted on data sheets. For some driver/baffle combinations, it can even add a 3-6dB peak!
Just another issue....
I'm trying to sim more than one cab stacked...so I take the jsg mighty dubpass script with the coupler...but if I set the num variable to 1 I'm expeting to have the same response without the coupler....but it's so different at all.