Hey nobody ever said you can't remove the old ferro and install new. I mean really, is buying unmatched drivers, in unknown condition, from whatever source the solution? Why not if possible fix the matched OEM's they were designed with in the first place. I've managed to do so many times. I find that most treated drivers employ to much fluid. And over dampening is the end result. Not to mention the outcome once it hardens. Removing and replacing the fluid is not rocket science. Just be careful while dealing with the fine voice coil wire while pulling and replacing the cone assembly. And make sure to make a few realignment scribes prior to disassembly. Then you can reinstall it back into alignment. Other than that just clean the crud out. And reapply fresh tar if desired. Solid copper wire strands work well to dig it out of the magnetic gap. Fresh fluid can be sourced at the usual online sites. So damn the engineering, as the number one issue being addressed is burnout warranty repairs. Everything else is considered secondary and that is why it was developed in the first place. I'm not sure about the 28, but the good thing about the 10 is it has a tweeter level control. That combined with proper equipment selection allows for easy correction of what is deemed as excessive brilliance. Should you even encounter it. I didn't with the OEM polycarbonate cone. Plus there is only one cure for for drivers that have had the tip top sparkle padded out in an attempt to tame "irregularities". And that is to remove or replace it. I've experimented with different amounts of ferro in a few applications.? And have found by trial and error that the smallest amounts of fresh fluid to be ideal.? DD ? On Mon, Dec 7, 2020, 9:18 AM John van Son <jpvanson@...> wrote: Watch eBay. The Vifa/Tymphany D25AG-05-06 was used in quite a few different makes and models back in the '90s. So, used, but working examples show up with some regularity. Just be sure you get the D25AG-05-06 and not the D25AG-35-06. The latter won't work as a drop in replacement. If you're on a time crunch or want to try something newer and improved, the folks at Madisound offer a service to this end and can probably do a decent job parameter matching one of the offerings they have in stock. Just plan on spending $2-300 for a pair of whatever they recommend. |