That is correct Dru.
Normally we recommend setting the VTF volume knob somewhere between 9-10 o'clock, and then adjusting the subwoofer channel level upwards or downwards in 1db increments to one's tastes. Note that the gain control on the subwoofer is very sensitive. Having the volume knob 1/4 of the way up is not indicative of the unit running at 1/4 max power, as the gain control can always be made more or less sensitive by the designer.
Thanks again for all the kind words about the product!
Pete - Hsu Research