Who are some of elite sub woofers?

JL Audio.  All the adjustments you need to perfectly integrate, a flat response that covers the notes in music (not just one!) and powerful amplifiers that get the job done.  

You can create a higher level in realism with a subwoofer in phase than any system without a subwoofer. In the past, I was never interested to use a subwoofer for stereo. But when I was able to use a room correction system that measures both loudspeakers and subwoofer together a new world opened. 

This world creates new levels in realism in sound which were not possible without the use of a subwoofer. To be honest I never thought that we could integrate a subwoofer at this level of precision. 

Hi bo1972 
    I watched your reviews about power cables and Tru Fi . I appreciate the new approach  You used the Dragon power cable for the sub woofer for a "DNA" on this cable, capable of generating low immersive frequencies;
       I would have three questions about the Dragon :
    Would it be superior to the Hurrican power cable in low frequency and bass generation if would it be used to power an amplifier? (eg Hegel H 300)
     Is the Dragon generally superior to Hurricane or does it have certain valences that make it more relevant on certain areas of use ...?
     You said you should get Firebird to test them; if you had the opportunity to make auditions with Firebird where you would put it in comparison with the two, Hurrican and Dragon?  Thanks a lot for the answer

SVS x 4 of whatever model[I have 2 PC-2000's].2 of these would be in your budget
HSU good too and I don't think you could go wrong with either .I haven't heard any of the others mentioned but would try REL based on Pauls[ PS Audio] recommendations.