Hey wolfie62,
Gezz, I wish you and some of the others posters would read the details in the review regarding the differences between regular sub-woofers, like your Velodynes, and how an acoustic band-bass design are not the same thing. Your subs use DSP to control certain frequencies, instead of loading the driver in an unique fashion in a ported box which leads to a very different loading of the room by the device. I have used excellent pairs of sub-woofers for years with monitor speakers with excellent results. However, they never reproduced the weight/foundation of the power region in the music and allowed the spatial cues to effect the sound-staging to evolve into a three-dimensional illusion that the monitors completely disappear in. I could allows "deal-in" the subs, no problem in my listening space(s) and they worked fine without mudding up the mid-range's timbres or clarity. The NSMT band-bass platforms are a different approach and deliver sonicly a vastly experience then a regular active sub-woofer. In the review I asked the designer, Erol Ricketts,to explain the differences and why he chose to use this design in this model.
My excitement over these platforms is that they just don't take a reference level monitor's performance and add bass extension, but transforms them into delivering in a way that usually is only done by large multi-driver floor-standing models without losing any of the tonal purity and sound-staging magic of small two-way designs.