Tweet
For anyone generally curious -
For the better part of 18 years I've admired the engineers at Bowers & Wilkins for their methods in driver development, specifically the FST midranges. The way they controlled the amount of resin in select strands of the Kevlar to control break-up modes, cancel odd order harmonics, the use of FEA etc. has always fascinated me. Zaph measured the older Kevlar variant several years ago and it really appeared to be a stellar performer, besting even the top of the food chain (available to us DIYers, at least) with distortion numbers and efficiency in particular. I got a wild hare a few weeks ago and snagged a pair of newer OEM FST Continuum mids that are normally used in the 704 S2 towers.
Build quality is second to none. Everything here was designed with a purpose and they feel solid as a rock. The fit and finish is gorgeous. The aluminum trim ring, the stout aluminum frame, massive neo ring and thick top plates, everything about these screams quality.
I assumed these mounted with an M6 bolt from the rear like the older models, but these have an interesting party piece. The dust cap is a thick foam plug that pops out, providing access to the top of the pole piece. This is how you remove the original brass nut to replace the driver in the 704's according to the service manual I found (they even make a special tool kit for it, because of course they do).
Kapton formers, copper shorting rings, and the top of the former edge has a plastic ring around the perimeter which holds the dust cap in place firmly.
I cut a test baffle for these and stuck them in our chamber here at the office.
Unsmoothed 0-60 degrees, note the sensitivity.
THD is below 0.2% from 500-3k, averaging around 0.16%. Third order is down more than 60 dB in this range.
They appear to be as good as I hoped, even out of a "lesser" 700 series model. I plan to use these in a future 3/3.5-way tower with dual Scan Speak M22WSR-46 woofers and TL N26CR2-A tweeters, but that probably wont be happening for a few months. I'll try to do a build thread when that happens.
For the better part of 18 years I've admired the engineers at Bowers & Wilkins for their methods in driver development, specifically the FST midranges. The way they controlled the amount of resin in select strands of the Kevlar to control break-up modes, cancel odd order harmonics, the use of FEA etc. has always fascinated me. Zaph measured the older Kevlar variant several years ago and it really appeared to be a stellar performer, besting even the top of the food chain (available to us DIYers, at least) with distortion numbers and efficiency in particular. I got a wild hare a few weeks ago and snagged a pair of newer OEM FST Continuum mids that are normally used in the 704 S2 towers.
Build quality is second to none. Everything here was designed with a purpose and they feel solid as a rock. The fit and finish is gorgeous. The aluminum trim ring, the stout aluminum frame, massive neo ring and thick top plates, everything about these screams quality.
I assumed these mounted with an M6 bolt from the rear like the older models, but these have an interesting party piece. The dust cap is a thick foam plug that pops out, providing access to the top of the pole piece. This is how you remove the original brass nut to replace the driver in the 704's according to the service manual I found (they even make a special tool kit for it, because of course they do).
Kapton formers, copper shorting rings, and the top of the former edge has a plastic ring around the perimeter which holds the dust cap in place firmly.
I cut a test baffle for these and stuck them in our chamber here at the office.
Unsmoothed 0-60 degrees, note the sensitivity.
THD is below 0.2% from 500-3k, averaging around 0.16%. Third order is down more than 60 dB in this range.
They appear to be as good as I hoped, even out of a "lesser" 700 series model. I plan to use these in a future 3/3.5-way tower with dual Scan Speak M22WSR-46 woofers and TL N26CR2-A tweeters, but that probably wont be happening for a few months. I'll try to do a build thread when that happens.
Comment