A fantastic little device.
I try this on a Wilson Benesch Torus subwoofer, probably one of the fastest subwoofers on the market.
The Torus is a passive subwoofer which comes with its own dedicated subwoofer amplifier and crossover but lacks automatic equalization which I think is essential for subwoofers.
The Torus was placed in the center of the front wall, mid point between the two main speakers as recommended by Wilson Benesch.
Now, this is the Torus running full bandwidth with no eq.:
As you can see, the Torus has significantly less output after 50Hz without eq.
So how did the 8033S-II do after the calibration?
I am very impressed. With the one 42Hz null, the Torus is now essentially flat from 20Hz to 200Hz. With the 8033S-II in place, the bass is far smoother and has more ‘power’ throughout. Fantastic unit!. Highly recommended!