@navyachts Have ML lower the boost point from 100 Hz down to 80 Hz and maintain the volume at 20 Hz. Rooms are always a problem from bad to terrible.
The M1 is really a DAC and a very good one. Your current speakers are better. You can make any speaker "active" with the right preamp. What I would do in your situation is get a MiniDSP SHD Studio use your M1 on the main speakers and get a less expensive DAC like a Benchmark to run subwoofers. With your system I would get two KEFs and place them inside the MLs right up against the wall. With the MiniDSP get the UMIK 2 (much better). MiniDSP uses DIRAC live,the easiest of all the room control and bass management systems to use. Dirac live will walk you right through the measurement routine, just follow the yellow brick road. The MiniDSP has a digital equalizer built in that is self explanatory and will allow you to make adjustments. You can make your system sound any way you want. I have set up two systems with SHDs so I can handle any problems you might have.
I do not know what amplifier you have. I would like to see either a Parasound amp on the less expensive side or a Pass or Bricasti amp on the more expensive side. The Bricasti M25 or a pair of M28s would be perfect and these amps are the most indestructible amps I have ever seen. Even I can't blow them up.
@brunomarcs Snakes? Sorry about that. I will give you a different link, maybe this will work. https://imgur.com/user/mijostyn/posts Yes, there is a driver in both ends. the interior volume is 2.15 cubic feet. 0.5 cubic feet are taken up by driver leaving 1.65 cubic feet total. 0.825 cubic feet is a little larger than one of these drivers calls for, lowering the Qts of the subwoofer. This was a wild guess on my part given the interaction of the two drivers being in the same cavity. Uncorrected they are down only 3 dB at 20 Hz at 6 inches with a very flat curve up to 0 dB at 100 Hz where they are cut off. Efficiency is about 89 dB by coarse estimation. As a system the four subwoofers are spaced along the front wall to form a line source. This matches the power radiation of my main loudspeakers and limits room effects. Because the array is horizontal it sends no radiation towards the side walls and in my media room there is essentially no rear wall. The next solid wall is 75 feet away. Consequently, the bass is very event throughout the room with maybe a 3 dB barrier boost at the side walls.
I stock Walnut, Cherry, South American Mahogany, Maple, Gabon ebony and Cocobolo. Some I source myself, some is kiln dried from a local supplier. I buy in large quantities because it is much cheaper and I love looking at big piles of wood. I get turning blanks from local tree surgeons and I steal burls from the woods around my house 
