Parametric EQ : Q factor not good

This product is very good, but is no good for the purpose that I bought it:

I bought this product to use as a narrow band bass 'cut', to 'EQ the room' for my PA system, i.e to remove standing waves. The specification is RATED AS CAPABLE OF THIS, at 1/2 octave to 1/4 octave i.e, a 'Q' of 4 to 7. I find this not to be the case. The Q factor is too wide, and to remove a resonant bass frequency from a room, too many frequencies are lost. To prove this, I tested this product at my work on a frequency generator and scope at 400Hz and the Q factor is very wide at the narrowest setting. I would like to say the unit build quality is very good and has low noise and will work very well for anyone looking for a wider band lift or cut, it just doesn't work for me. I will try a bass EQ pedal in the future.