Over the past 40 years in audio I’ve become a fan of speakers, KISS, and not breaking the bank. As a result my current main system consists of a B-stock Onix CD-3 (transport); used Behringer DEQ2496 (DAC/DEQ) modded by Scott Endler; used Channel Island Audio VMB-1 chip based 40 watt monoblocks; stepped attenuators, digital cable, interconnects, and speaker cables by Scott Endler; Bob Brines FTA-2000 speakers, and a dedicated listening room/setup ala Cardas (8ft x 13 ft x 21 ft) that is insulated mechanically and electrically which was built with the house 4 years ago. My musical preferences follow the baroque, various mainstream jazz genres, and classic pop.
The F200A has a different character than most extended range drivers I’ve heard (for one thing it extends over 9 octaves). It exhibits none of the thin, shouty personality found in many extended range drivers, but unfortunately it’s not as efficient either (91 dB/m/w at 8 ohms, 30 – 20,000 Hz). And without a whizzer cone it beams mid-treble and higher frequencies. The cost of these very heavy, well built AlNiCo drivers, currently about $400 USD each, is enough to keep most DIYer’s at bay. Because of its lower efficiency, rich sound, and relatively high price it has become a bit of an orphan as the F200A has been shunned both by the typical single driver/high efficiency crowd that favor weak bass but love their SETs, and the main stream audio community that has never appreciated the advantages of single driver designs.
For the past 5 years I’ve been the happy owner of these fine speakers (in fact it was my idea to mate the Fostex F200A driver with Martin King’s transmission line theory in the first place. Bob proved to be a most qualified technician and woodworker in completing this marriage. The cabinet removes backwave reflections from coming back through the cone and extends the bass even further in typical transmission line fashion. So the FTA-2000 has a very deep, nicely detailed, and full bodied presentation that stuns most single driver fans.
Although quite satisfied with the speakers I was persuaded by a long time audio friend to send them off to Bud Purvine to receive the EnABL treatment. Visitors to the diyAudio site will know that Bud has been at the forefront of the development of this technology since the 70’s, but spends most his time heading up Onetics Transformer Company. Once treated Bud considers the treated F200A as one of the best drivers in the world (no faint praise coming from Bud). He was intrigued to work on my drivers himself as they had 5 years of daily use on them and so were broken in far beyond any he had worked with previously (and these are some of slowest break-in drivers around).
Frankly the whole EnABL concept is beyond my understanding, instead I refer you to diyAudio:
http://www.diyaudio.com/forums/multi-way/100399-enabl-processes.html?perpage=25&pagenumber=1 for more information and discussion. Bud spent the next 8 weeks listening and applying the “stealth mode” (colorless) raised dashes in several rings around the cones (front and back surfaces) as well as to the frame. He also applied a varnished finish to the cones. Note that unique patterns of these raised dashes have been developed for a variety of drivers. Along the way he developed a head cold and so had to stop working on them for a while.
In the past year I’ve replaced my entire system save the chip amps, speaker cabinets, and drivers. Even the baffle step/zobel circuit that the FTA-2000 include were pulled with the addition of digital equalization so that the purest possible signal path could be provided between monoblock and driver. These upgrades have made a series of noticeable improvements, particularly the equalization. Upon receiving my modified drivers back, I frankly was underwhelmed. Keeping in mind that I’d been slumming with $350/pair standmounts for 9 weeks, I’m sure that I was a victim of aural memory loss, but the very modest gains I was hearing didn’t change for the first couple of weeks. But finally the drivers seemed to “wake up”.
Now after 100-200 hours of listening, better recordings exhibit more resolution both in terms of detail (lips pursing, texture of guitar strings, wooden block, etc.), leading/trailing edge of individual notes, and more natural (if not audio typical) tone. In fact these speakers are now tone monsters, especially throughout the entire midrange. Separate layers of cymbals and snares with brushes can be heard. Images are even more discrete and tightly focused. Gritty sounds are grittier. Poorer quality recordings show little difference, but haven’t been made worse either, which allows me to continue enjoying my full collection. My lack of musical knowledge and experience with various high-end instruments is now the limiting factor in my system.
I could have tried doing the EnABLing myself, but wanted to “give back” or “philanthropize” towards the development of this technology. While the cost wasn’t insignificant, it was particularly rewarding that Bud discovered that, based on the 5 year break in on these drivers, an additional ring of raised dashes were needed to really optimize their performance. I understand that the recipe for this improvement will be passed on the public.
