Finally got round to ordering some better bass drivers for the KEF Concord III conversion at the very high end price of £19 each.
They’re Skytronic 902.208 8″ polypropylene drivers, and as you can see, they’re quite a bit beefier magnet-wise than the Peerless SKO200.
There seems to be some confusion about the Thiele Small parameters for this driver. As far as I can tell, the ones here are correct. It probably works out that the 30l KEF cabinets are too small, and we end up with a Q of 0.97. No matter.
I have measured the driver in the cabinet in the nearfield, and attempted to correct it for phase and amplitude, and then modified the filter to give me a driver with 38 Hz corner frequency and a roll-off at 12dB per octave. The cones move quite a lot sometimes, but the sound is good.