Hello all,
Thought I'd drop by and introduce you to the newest member in my HT family:
MX-125 MkII Subwoofer
Drivers: (2) 12" long-throw MK125
Push pull configuration virtually eliminates even harmonic distortion
Built-in 150 watt RMS amplifier
Active Headroom Maximizer IV design to prevent clipping
Adjustable 50Hz-125Hz low-pass filter with bypass
Frequency Response: 20 - 125 Hz ± 3dB
Weight: 64 lbs
Dimensions: 23" H x 15.25" W x 19 5/8" D
I was really impressed with Subs with multiple drivers in the same unit, such as the Martin Logan Descent, which utilize the configuration to cancel out cabinet noise and vibration. I came across the now bankrupt (but soon returning) Miller & Keisler line of subs. According to a review I found: M&K's MX-125 subwoofer houses two long-throw 12" woofers in a push-pull configuration. These are the same drivers used in the THX-Ultra certified MX-350 MkII subwoofer. This design has one driver facing into the room while the second driver faces up into the bottom of the cabinet. Both drivers are wired electrically out of phase, but acoustically in phase with one another, doubling the amount of acoustical power into the room.
I was lucky enough to find this beauty in Craigslist and finalized the deal today at an unbelievable price of $125!!

I already hooked it up and am totally blown away. I did not know I was missing bass until I tried this one out. Totally awesome!
Here's a few more pics:
The M&K next to my 12" AA for comparison (notice that the AA is on a riser):
Here's a better view of the second 12" Driver:
This sub is in great condition.
A few interesting facts about M&K:
For a while M&K was the highly recognized speaker manufacturer in the US. Their speakers were used in the making of several of the Star Wars movies. The founders have been credited as the first subwoofer makers. In 2007 they went bankrupt, but recently they are being resurrected by a UK company and are now starting to make speakers again. Check abt.com to see some of the new lines, which include high end subs still utilizing the dual configuration shown above.
From my research, the quality of the older M&K speakers are fantastic and can be had at very reasonable prices if you can find them (people have never heard of them or are not interested due to the bankruptcy). But I have also found that parts are very easy to come by on ebay, in fact I am thinking of upgrading the drivers with an upgraded model which are supposed to increase the output by 6db.
I used the funds I had set aside to upgrade the 12" driver on the AA and was able to get a whole Sub unit with two 12" drivers. This purchase came totally unexpected and may be the best purchase of the year!
