I use the BSC filter in both of my Fostex speakers. It works just as well with the Fostex as with the Lowther drivers. In my Fostex FE-208 Sigma ML TL, I even added a 2 uF capacitor in parallel with the BSC circuit to "extend" the frequency response a little bit higher. I had been trying to decide if I wanted to add a super tweeter but this little trick did the job and I have not gone that route. Those speakers ended up in my family room and even my wife comments she likes them. The kids give them a good workout every once and a while, I guess I do to on occassion, and they have performed very well.

Martin