John Dunlavy makes no apologies or pretense for his choice of drivers. Older Dunlavys relied on dynaudio drivers until dynaudio got upset with the hassle (John returned a huge percentage of drivers that were out of spec). His position is that at this point in time and technology the challenge is one of QC and design, not magical materials and construction voodoo. The Dunlavy line is to a great degree experimental proof of that hypothesis.
One reason many Duns on the used market are so cheap is that the owners have been forced to replace carefully selected drivers with off-the-shelf vifa's, lacking the expertise and facility to match them. Afterwards the speakers are easily bested in a shoot out with a less-tired, factory-fresh newcomer. If you look at the documentation that ships with the higher-end Duns you realize that the QC doesn't stop with driver selection, but extends to matching every component, and testing them individually AND together. When you bought a replacement tweet from Dunlavy they weren't especially expensive, and they recommended you replace it's partner at the same time. The replacements matched the originals as much as possible, with stock on their shelves. You could get individual drivers, but the results would vary, depending on age, use and environment of the survivor.
I'd heard that John was selling replacement drivers on his own, but haven't heard from him. He supposedly retained the records and measurements from units sold, so he can match them to each other and your cabinet. THAT is what makes a Dunlavy or Duntech speaker sound so special: tuning all the parts to achieve a measurable spec. This accounts for audible variations in resonance, response and performance in cabinets, drivers and electronics. While the wood and drivers change with time, and could require re-measurment at some point, the largest variables with his designs are the drivers in general, and the tweets in particular. Theoretically any Dun could be returned to factory-fresh specs at any point in time by John with a simple and relatively affordable driver swap. An owner with calibrated measurements of his originals in situ could do the same with some patience and hassle (swapping).
The Dynaudio drivers were nearly indestructible... even the tweets could handle absurd, unlistenable levels. My mains use these, and have survived events that should have killed them many times over. My surrounds use the vifas, and sound great, but I doubt they'd survive the abuse their older brothers have taken. Still, it's a fair trade off: the more recent Vifa-driven duns cost less, relatively speaking, than the older Dynaudio-powered ones, but also had extended frequency response and improved measurable performance. It wasn't a big step backwards, just a fair move sideways.
-d-
