Last year I plucked a pair of these speakers that had been tossed to the curb for garbage pick up.
With the exception of the metal dome tweeters, the rest of the drivers look okay. After a closer look, I found that both the crossovers located in the bottoms of the low frequency cabs had caught fire at some point melting into the foam padding holding them in place. The crossovers for the midrange and tweeters in the upper cabs didn’t burn, but did trip the APOC circuit protection module. B&W’s parts website lists the mid and tweeter crossovers as still being available for $87 each, but the LF crossovers are no longer available.
I’d like to rebuild the HF crossovers sans the APOC circuitry and do a complete rebuild of the LF crossovers sticking as close as possible to the original specs and without spending a bunch of cash. I can salvage the inductors for the HF boards, but I want to replace all the resistors and capacitors with comparable or slightly better components.
I don’t think I’ll have a problem rebuilding the LF boards, but I was hoping someone could explain why B&W chose to include a MF crossover between the LF board and the existing MF board in the upper cabs as well as reversing its polarity. I’m a little bit concerned with the HF boards due to the APOC circuitry and I’m having trouble determining where the APOC stuff stops and the the primary crossover circuitry begins.
Any help and recommendations would be much appreciated.
The crossover schematics can be found here:http://bwgroupsupport.com/downloads/techmanuals/bw/CM2%20Concept%2090-TM.pdfhttp://bwgroupsupport.com/downloads/techmanuals/bw/CM1%20Concept%2090-TM.pdf