MBM-12 paired with Ascend 340Se's: neccessary?

[HP666]

I was considering the addition of an MBM-12 to go with my VTF-3 MK3, but I'm having second thoughts. The Ascend 340SE's have such accurate and solid mid-bass performance, well into the 40Hz range, do you think the MBM-12 could actually be detrimental to sound; and interfere with stereo imaging? I've heard frequencies above 80Hz become directional and you'd want that coming from where it was intended to come from, the two front speakers. Not to mention the possible phase problems. I'm far from knowledgable on these things that's why I post this here.
Also, if I was to get an MBM-12 it would go inside my right front speaker, while my MK3 is inside the left already. With both about 7 feet from the listener/viewer.

[HP666]

No opinions???

[Stan]

The MBMs would clearly have a large output advantage over the Ascends.

http://www.ascendacoustics.com/images/products/speakers/cmt340m/340prxsmall.jpg

I really prefer to see a single, separate, manageably sized midbass device nearfield mounted, generally directly behind you. As one of the possible positioning choices it should be tried and tweaked. A big reason for getting such a device is the nearfield benefits such as the very even frequency response in musically important and very active frequency ranges. This is due to lessened room effects from the proximity. Not to mention the noticeable impact, output, and tactile energy aspects.

If you MUST place the bass speakers so that they are visually symmetric to the mains in already determined position then this can diminish the results to a degree. Especially tactile / impact type action. I like to run nearfield midbass behind the best seat(s). You can eliminate or greatly reduce audible locatability. You can retime the bass sounds from it with the other speakers via delays. If you try it, pay attention to tactile aspects of the bass experience. Some love or hate touchey-feeley bass. Both views, plus neutral, are correct! It helps a lot to play with setting up nearfield mid bass speakers and trying out various combinations of settings, staggering crossover frequencies at times. In your case if you are concerned about 80 Hz then you can play with lower crossover frequencies.

I have not measured one, but I would imagine that the Hsu MBM has low distortion. Harmonic distortion can increase the locatability of bass speakers. Since an 80 Hz tone would involve harmonic distortions at multiples of that frequency. Like 160 Hz, 240 Hz, etc. Those higher frequencies are most certainly more locatable than the fundamental.