I bought the REL new in October 2004 and have been more than happy with it. It plays tight and deep without any problems, but the upgraditis bug is clawing away again so my question is:- Due to space limits, a new sub would have to fit in to the space of my existing REL up to a maximum width of 48cm. The sub that has caught my eye is the Velodine DD15. To justify this extra cost does anyone have any views on whether this would be a dramatic improvement over my REL, and can the DD15 be connected to both high and low level inputs and used at the same time? If I were to purchase the DD15 I would then have to sell the REL, what would be a realistic selling price?