Subwoofer for Wilson Maxx2

my room are fully concreted construction, and in fact the Volume may be about or above 7000 ft3

i want a pair..since..i suspect the crossover point will be at around 50 to 60hz.., from that range, there may be some stereo image, and from many findings, it make some sense for having a pair but not just one ..from the volume prospective, a pair is already made some sense

david wilson use 2 hummers for his pair of X-2 too..

Wilson Maxx2 in your size room should have good Bass. I think there must be something wrong. What amplifier(s) are you using to drive your speakers? Also a description of you sources components? What is your cabling? I had a similar problem with a clients system. When I arrived he was just a customer after I solved the no bass problems along with other issues he became a client. The problem was similar the speakers are Avalon Eidolon Diamonds. He did not need a sub-woofer. Bought a couple of good power cords and I fixed the polarity at the outlet. The polarity at the wall was not right. Buy plug tester from Lowes or Home Depot and find out if you need to switch the wires inside the wall outlet. Next we replaced all the interconnects and speaker wires. The bass on this system is correct and it sounds great. You may already have good cabling but it might not be a good match for your system.

My bass improved after treating for bass and I have a watchdog I don't use any more. Maxx 2s in a similar position to yours in almost the exact same size room. Went through the same thing as you. Moving out into the room gives the best mids & highs but the bass impact goes down. Yes you can use a subwoofer from 35Hz down but 1st treat the room with bass traps. I understand you treated it for 1 or 2nd order reflection but bass traps in the corners actually increase bass resolution and will probably demand a slight change in speaker placement. Trying to save you money. If you are a DIYer you can make your own bass traps for near nothing.

speaker's need to be closer to the back wall. Voice them as instructed in manual and or add bass traps. Those speakers have plenty of bass.

I sort of agree with Rockitman. I use Maxx 2 now, Wp before these, and could not imagine having them that far into the room. Did you adjust the head unit, spikes and toe in when you moved them back? I also think something is not right somewhere. They should be full range and do everything very very well ( closer to the wall and corners ). I also think if you are going to cross them over that high, it is not worth it having Maxx's.

You're speakers are basically 60% subwoofer already! After that, it's cables, gear and the room.

Blending a sub with Wilson's is not as easy as it sounds. They have a unique flavor and I could always hear the sub with the exception of very very few. You almost have to go Watch Dog to get seamless sound. The bigger Thiel may work.