These are my favorite analog crossover :D, did you score these from "Trade Me" I seem to remember 2 there a while ago?..... Tip ! wire the limiter so it is defeated and remember the output is unbalanced although on an XLR. Here is the manual if you don't have it
http://www.bssaudio.com/product_down...s/fds360um.pdf I'm not sure what the recommended crossover frequency for the 4344 is but no doubt someone will chime in here with it, just get the frequency cards RC values changed to suit (consulting the manual) and they can be configured for either 12 or 24 dB slopes. As each FDS 360 can be configured as a 2 way stereo or 4 way mono, configure them both as 2 way stereo and use one on both sets of loudspeakers.
I converted my Tannoy Berkley HPD385A's to 24dB LR filter network back in the very early 80's and was very pleased with the improvment from memory, what Tannoy drivers are you using?