BEST SUB FOR HT:MUSIC 50-50 with CM9/CMC2/CM5

SVS make awesome subs, even the drivers are built in house.

I have the same speakers I have a Martin Logan depth i. But I will be trying the supercube 4000 in a week. I will tell you the winner after I try both.

Without a budget and the word, "best," in your question these AGone links should provide a quick variety of size, price, and features, that may suit your needs. Happy shopping.

http://app.audiogon.com/listings?search_text=velodyne%20&page=1&no_listing_types_auctions=false&no_listing_types_classifieds=false&items_per_page=50&location_filter_radius=25&filter_category_id%5B%5D=30&min_condition=1&max_condition=11&listing_types_auctions=1&listing_types_classifieds=1

http://app.audiogon.com/listings?search_text=JL%20audio&page=1&no_listing_types_auctions=false&no_listing_types_classifieds=false&items_per_page=50&location_filter_radius=25&filter_category_id

Do not only consider the size of the subwoofer. You should consider the power, sensitivity rating, and enclosure type. If you would like the system to play loud, low music, and you also have enough space, then choose the biggest subwoofer possible. Do not underestimate the small subwoofer. I am also using  some models at my Karate uniform store.

For music, you’re MUCH better off with two smaller subs than one larger one and will still work fine for movies. In your system and room I’d take a hard look at a pair of SVS SB1000s that you can get for about $1000 for both and I believe will get you down to an honest 20Hz despite their relatively small size, which will be nice for movies especially. And the new models come with integration software/app that should make setup much better and easier. They offer a very generous and truly risk-free trial period (including shipping) that makes it easy and painless to give them a try. I’d bet big bucks you won’t return them. Best of luck.