I suppose only time will tell though. I'm hoping I've got at least a couple more years on my 18.0
I'm sure you will. And I'm not of a mind that a particular driver part material that I'm not an expert about would keep me from purchasing. Funk subs have attracted me for a few years now. The foam surround is simply a question that comes to mind.
I will say that I think more about longevity in speakers than I did even ten years ago. The Salon2s in my system are approaching eight years old, and the Velodyne sub is already six years old. In my auditions, it seems the Salon2s are still near the state of the art in their price range, and while Revel actively updates its more modest product lines, the Ultima2 series remains in place even though they were released in 2007. The Velodyne DD18 Plus has definitely been eclipsed, IMO, by other subs, like the 21.0LX, and I have been tempted to replace it, but the truth is I'm not even stressing the DD18 Plus in my system, no less a monster like the 21.0 (or the 24" Deep Sea Sound thing that tempted me for a few months). As I get cheaper and more practical in my old age, I wonder if I will ever need to replace the Velodyne if it continues to function.
Until relatively recently, it seems speaker technology improved at a rapid pace. Better drivers, better software, better materials, wider availability of CNC manufacturing products, probably other reasons, powered a steep improvement curve for a time, but now the performance improvement curve seems to have flattened out. Certainly for subwoofers one wonders how performance will be improved much over what that 21.0LX will likely demonstrate for home use. How much utility is there for 130db of output at 20Hz? Even for full-range towers... when the Salon2 was introduced it was a sensation, but now, I think other products certainly approach it, if not exceed it, yet Revel can't seem to produce a worthwhile follow-on. (To Revel's credit, the Salon2's MSRP is still the same as it was in 2007.)
I suspect that in general, competently designed speakers are getting much more difficult to improve upon at a given price level.
