Well the MBM-12 arrived right on time and I set it up immediately when I was home. I was very excited to get to try it out. Here are my initial impressions.
The box seems nice and solid. Looking through the huge 4" port I can see a cross brace and a good bit of stuffing. You can feel the top of the woofer just below the port so the woofer is fairly large extending up about halfway inside the box. The woofer seems very stiff and it has a accordion style surround (like you see on pro audio drivers).
I had pre-moved my Velodyne F1800XR into the corner in the front left of the room. It was originally in the front center. I ended up having to adjust the gain down some and I was happy to see that I was getting some additional corner boost from the new location.
My house is a open floor plan design with the living room / dinning room / kitchen all basically in one big room. The HT area occupies about 1/2 of the living room / dining room space. My couch sits in the middle of the room with nothing behind it so I immediately put the MBM-12 behind the couch. I did a quick calibration with a SPL meter to set the levels. With my Velodyne turned off I level matched the MBM-12 with the mains and then turned the Velodyne back on (~50hz xover on the Velodyne). When both subs were on the overall subwoofer level was about 3db hot so I dialed the master sub-out level down to match the mains. This seemed to get me in the ballpark with the levels.
The MBM-12 is super efficient. Including the min and max level stops there are 7 total hash marks around the volume control. I had it turned up about 3/4 of the way to the "first" hash mark past min. I am running powered monitors which are reasonably sensitive so it isn't like I am matching the MBM-12 up to Magnepans.
Initial listening test. I fired up some bass heavy CDs. OMG the bass punch is there alright, that little box can sure move some air. The bass was very tight and quick. I didn't notice any box noise or strange resonances. I did notice a huge increase in the tactile effect, in fact it was too huge. I initially set the unit up with the port facing the couch and this was just too much. I felt like I was sitting on a buttkicker. I turned the unit sideways with the port firing along the side of the couch and played with the levels slightly. Then I fired up War of the Worlds. Definite improvement in bass slam, the alien lasers were incredible. I know I am getting more total bass energy because I heard new rattles. The "True Sub" was impossible to localize with the 50hz xover. I had to turn it off to notice that it was actually working. Unfortunately I felt like I could localize the MBM-12 behind the couch (80hz xover on the processor). I mainly noticed it during the Tri-Pod steps. Next up was some Dark side of the Moon SACD. Here I felt like I couldn't really localize the bass except for the fact that I could feel the bass impact more on the back and bottom of the couch. I played some Linkin Park DVD-A and Blue Man Group Audio. The MBM-12 was incredible on both of those albums and I had definite improvements in bass even with my system level matched. However I couldn't get it out of my mind that the couch shaking tactile effect was a bit unnatural.
I moved the MBM-12 to the front of the room slightly off center (pulled out from the wall a bit) just to experiment with it. One benefit of the MBM-12 is that it's small size lends itself to being moved around. I adjusted the level and phase (I turned the gain up slightly to the first hash mark, plenty of headroom available).
I feel like the integration is optimum here and I am still getting improved bass response (more new rattles). It is not quite as effective on War of the Worlds as it was behind the couch, but clearly it is better for music listening.
So my evaluation will continue. I must say that I am impressed so far. The MBM-12 is the least expensive component in my system (Each of my Focal powered monitors cost considerably more) and it has made a definite improvement. I have never heard a 12" HT sub that can hit as hard as the MBM-12. I was skeptical at first since I already have a 18" sub and adding a 12" seems backwards, but the MBM-12 really works as advertised. My only minor complaint is that it doesn't have a variable phase control, on a item that is supposed to integrated between two other speakers it seems like that would be useful. I really like that the "True Sub" cannot be localized at all in the corner with the 50hz over.