I recently picked up the RSL Speedwoofer 10S after researching subs in the ~$500 department. I was in analysis paralysis between this and L12 which is $559 (which can be had out of b-stock for 519). As b-stock with Rythmik is few and far between, I finally pulled trigger on the 10S ($400) after watching\/reading a number of reviews and ultimately the RSL Speedwoofer manual (very witty and informative, I knew they we proud of their product). The 10S was delivered last week, and sure enough the sub is very articulate and brings the bottom end of music and movies to life in my living room that is a long rectangle with doors at each end and a large opening toward front left to dining room. I couldn’t believe my ears, but I was also replacing something that was very under-powered\/-sized sub.\n\nI know I could\/will be happy with this sub, especially with it being about $170 less than the L12. It is remarkable within its specifications. There’s even a shot taken at servo subs in their manual basically saying, if you build the cabinet right then, a sub shouldn’t need a servo to manage cabinet distortion. They have certainly achieved this with their masterfully crafted\/patented compression guide technology.\n\nIt here’s the rub, the extra $170 won’t break the bank, and I have read countless comments that say get the best sub you can afford that hits as hard and deep as possible. The 10S drop 6db from peak when it gets to 24hz (and plummets about another 6db to 20hz). While there is output those levels, and Plenty of volume left for sub to go louder, it would just require turning up every in 32hz and above way too loud.\n\nThe siren of only 3db drop from peak all the way to 18hz (and 6db to 12hz) keeps calling me with the L12 from Rythmik. So much so that I decide to just order the L12 (at full price) so I can do a shootout for myself. RSL will pay for return shipping if the L12 wins, but Rythmik does not. Should the RSL sound quality stand supreme for everything 30hz and up, I’ll be out about $80 in return shipping to Rythmik, but will have peace of mind that I did about as good as anyone can for this price range. (I know monolith, HSU, and SVS are out there with worthy contenders; they did not make my list after weighing pros\/cons of each of their offerings, and I’m not looking for comments about other options in this thread).\n\nThe L12 arrives this week; I’ll be sure to post back with more details if any interest is shown for this thread. I don’t have any sophisticated measuring equipment — just YouTube tests, levels on apps on my phone, and my ears. I’m open to ideas suggestions if anyone has them.\n\nRegardless of outcome, I will certainly be going to RSL for my next set of speaker purchases (a quality bookshelf offering at an incredibly fair price) — I just love the way that company rolls.