The latest and greatest


Sometimes I see a new product (in this case speakers) that get lots of press and discussion only to see lots of them for sale a little later. 
Right now there are many pairs of Kef LS50s coming up for sale (both the regular and W versions).
Are these just a flash in the pan or just showing up on the market because so many have been sold?
In my mind there is nothing like a product that has stood the test of time. 
Am I just being a sceptic?
crwindy
More generally, technical progress is slow. As for source technology, we have witnessed two breakthough moments. The first was the introduction of the vinyl lp that made 78’s obsolete. The second was the cd and the digital technology behind it, which made vinyl obsolete (whatever audiophiles may want to believe). With the cd, we have probably achieved sonic perfection. At the time, this was also the limit of what was technically possible. These days much higher resolutions are technically possible, but the question is if (unlike our dogs) we can actually hear the difference: human hearing is not that good.
A similar plateau has been reached with amplifiers. Ever since output transformers were largely abandoned decades ago, amplifiers have reached a state of sonic perfection where technical improvements were still possible (current ampifiers do measure better than those from the seventies), but again the question is whether we can hear those improvements. A good example of the technological continuity that was inaugurated is Quad’s current dumping technology, first presented in 1975 in their 2x100 watt 405 model, and still the basis of their current 2x140 watt Artera model. The biggest benefit of advancing technologies has been higher output powers for lower manufacturing costs.
With speakers there has not been such a plateau, since speakers are still far from perfect. Slowly but steadily speakers have improved, with new materials, new computer simulation design technology and new manufacturing technology. But progress is slow. I am now listening to my Harbeth P3ESR desktop speakers, proud descendents in a direct line from that remarkable BBC design from the seventies, the LS3/5a. I still have both models, so I can compare: the new Harbeth is much better, but it is also clear that they share a family resemblance. Progress has only been incremental. The same can be said about my main speakers, now the Quad 2805 electrostats, but the ELS57 before.
My hunch is that the biggest jump in domestic audio quality will be the adoption of more advanced dsp technology in active speakers, both to improve on traditional crossover technologies, and to equalize room effects. I also expect one other trend, even if it will do nothing to improve sound quality: reduction of energy consumption. Here in Europe, concerns about climate change have not only introduced mandatory specifications for energy consumption by refrigerators or vacuum cleaners (our new one only consumes half of our previous one, but is also much better), but now also for televisions. High end audio is obviously a much smaller and hence less important market to address, but the writing is on the wall.

With the excellent word of mouth when they first came out, KEF probably sold a lot. Some of their buyers were caught up in the excitement of the moment. A couple of years later, they’re looking for the next big thing.

The number of used Martin Logan speakers (and to a lesser extent) Monitor Audio for sale, is more of a cause for concern.

One challenge with the LS50 is that the Elac UB5 is very similar sounding for a fraction of the price...albeit without the cool factor or build quality.  

The LS50s are mostly a single point source and that is an improvement over the BBC type monitors, especially near field. 

LS50s are bass shy and are a little hot in the upper mids...which can cause fatigue and eventually a breakup. 
Right now there are many pairs of Kef LS50s coming up for sale (both the regular and W versions).

IMHO: They look good = Buy. Later ... They sound crap = sell. I’ve never liked Kef. I just don’t get those metal drivers and I think that is why they suck.
Classic old school look with superb build quality and great sound: Tannoy.  I wish I could afford their top end speakers