Subwoofer Advice

@grislybutter The Balanced Force series are much better. They are not perfect, but they are better than most. The enclosure creates distortion in two ways, shaking and vibrating. Both types occur around certain frequencies. Shaking is caused by unopposed driver forces. When the cone is pushed forward the enclosure is pushed backwards. This is completely cured in balanced force designs. Then there is vibration in the walls of the enclosure. This is not so easy to stop. It takes intelligent design, over construction and the right materials. The problem for commercial manufacturers is this is expensive to do and makes their products uncompetitive in the markets they serve. The Magico Q series subs cost $36K!  

@big_greg You are right, this is a diversion, but @navyachts problem has been successfully addressed and his interest has been diverted to the subwoofer question. I am nowhere near the most intelligent person on this website, but I have been using subs with ESLs since 1978 and building subs since 1987. Experience being the teacher that it is I feel qualified to deal with his situation. ESLs are like the most beautiful girl you wish you never met. It is easy to make them sound terrible putting additional requirements on associated equipment, particularly amplifiers and subwoofer systems. 

@mijostyn Just an update, the bass has been a bit too heavy on both the .arc3 files that Anthem has provided me so just this morning I have asked them to edit the file again to see if they could tame the bas down a tad more.

I have a fair bit on $ invested in this my system and not 100% satisfied in what I'm hearing. You mention amplification as did @sounds_real_audio. Should I be looking at an alternative to my power amp? I did notice an improvement in sound when using my Coda pre-amp over the preamp in my Bricasti M1, so maybe a change for the better could be had with swapping out the power amp?

Failing all of this, if the room is truly the problem, I was thinking maybe of liquidating what I have now and in turn maybe trying an active speaker like ATC or maybe Dutch & Dutch 8c with its built-in DSP? Certainly not the most beautiful girl in the world, but maybe they would suffice.

@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 

@mijostyn I would hope it doesn't have to cost 36K to solve all these problems. My solution with my very entry level Polks is low gain, that still produces the live sense of "beat in my chest" 

@mijostyn Coda #8 power amp, it's listed in my AG Virtual System.