If your willing to spend 12k or a tad less , the Ken Kreisel DXD12012 in a Quattro stack ( 4 subs 8 drivers in a push pull configuration with 10hz extenstion) in a pulsar configuration would be mind boggling and extremely musical, I have one DXD12012 and it will change your definition of what "true bass" sounds like! clean , clean, clean!
Ultimate sub?
So I have been in a slight upgrade stage recently. I just purchased a b&w HTM2 and I'm shopping for a sub. There is never much talk about subs it seems and so right now my two options are the Velodyne DDPlus 12 and the JL Audio Fathom 112. Are there any other manufacturers I should check out? This sub is an ultimate system purchase so I don't want to make a misstep.