Sub upgrade advice please

[basshound]

I am considering upgrading my sub following a recent speaker change.What I want advice on is would I hear a reasonable improvement over my current BK with a budget of £1000 max.? The sub is used exclusively in a stereo setup and I listen to a lot of bass heavy music but also have a pretty varied taste. Thinking I`ve been struck down with upgradeitis as I`m pretty satisfied with the BK but as always can`t help wondering if it could be bettered!

 

[Anonymous]

I would change the DAC...

 

[bretty]

There's a REL STRATA 5 at Steve's hi fi. I saw it last week, and it's a beauty. If I had the £395 right now, i'd get it myself.