Somehow 😢 I've blown up a mid range driver on a 1984 B&W 801F speaker. I still don't know how I did it, but it has gone open circuit (well, about 1M) and has a very faint burning smell to it. The terminals are fine and I measured their resistance across the tinsell leads to make sure. This happened while the driver was tri-amped with a home constructed amplifier and I suspect that while I was testing different configurations of the amp earth wiring to minimise earth loop hum an output tranny has shorted and fried the speaker. The amp is fine. Base and tweeter are both fine, so it's a bit of a mystery and also a lesson to use a crappy old speaker when testing amplifiers.
What to do? Is such a fault repairable? Is there any other possible cause of these symptoms? Are there any drivers out there that would be a potential substitute for the original? I'm OK with soldering fiddly parts, but I doubt very much that my DIY skills would extend to voice coil winding.
I would dearly like to remedy this as the tri-amped 801s sounded absolutely heavenly.
Any advice very gratefully received.
What to do? Is such a fault repairable? Is there any other possible cause of these symptoms? Are there any drivers out there that would be a potential substitute for the original? I'm OK with soldering fiddly parts, but I doubt very much that my DIY skills would extend to voice coil winding.
I would dearly like to remedy this as the tri-amped 801s sounded absolutely heavenly.
Any advice very gratefully received.
The driver is a paperweight now. You need to get the part number on back of it and look for a used one on ebay. You probably just need to put a fuse in line with it for some protection (1.5 A would be sufficient). Sounds like there is also a crossover fault letting DC through. Oscillation from the driving amp could also be a culprit, but usually the higher VC inductance doesn't permit enough current at higher frewuencies, unless the amplitude was high enough. I highly recommend going through the crossover and checking the HP capacitor for short circuit.