Sunday, November 2, 2008

First Generation KEF Uni-Q Driver

A few months ago I bought a pair of KEF C-75 speakers - these utilize KEF's earliest version of the 8" Uni-Q driver which is essentially an advanced coaxial speaker. With the C-75s an additional 8" bottom woofer provides the bottom bass. The MB200 Uni-Q driver is an 8" woofer with a neodymium tweeter which is small enough to be placed right inside of the bass voice coil. This makes the speaker act as a true source point. Oddly enough for the all the hype that surrounds the Uni-Q drivers, KEF's historical section fails to mention the C-series of speakers from the late 80s. Go figure.

One of my KEF MB200 drivers was bad - turns out the seller fried the voice coil. Probably a bit overzealous with the power. I've had to search and search, but I managed to find another driver. Here is the broken down one:

I pulled off the attached crossover and had to desolder the wires leading to the enclosed tweeter.

And removing the magnet assembled I was able to get to the tweeter inside.

I failed to remove the bad voice coil in the woofer magnet - it was actually fused due to the voice coil varnish being heated up (clipping solid-state amp for sure!) and the varnish bubbling off.

I have a pair of KEF C-35s being shipped my way - I will have to switch over one of the drivers, attach the C-75 crossover and I should be back in business. Stay tuned for an update coming soon.