Just to conclude this, I disassembled the speaker with the failed HF driver unit, disconnected the HF drive unit from the crossover unit, and measured the resistance through the suspect HF drive unit coil, which proved to be open circuit – ie, dead. So I went ahead and ordered a matched pair of replacement HF drive units from KEF, for £78 delivered the next day.
The units dutifully turned up the next day, along with detailed instructions on how to replace them. In total it required about an hour, mostly because it involved some soldering of connections inside the speaker, which although straight-forward, was a bit physically awkward.
And the good news is that the speakers are now sounding as good as new again.
However, when that HF unit initially failed, I had started thinking of replacing my speakers with a 5.1 speaker set. And the thought of moving to a surround sound set-up has stuck with me, to the point where I started investigating how to create a 5.1 system using my KEF Reference 101/2s as my L+R front speakers.
After some good advice from the avforums website, and a chat with the historic speaker experts at KEF, I was advised to try to find another pair of Reference 101/2s for my rear speakers and a Reference 100c, or 90c for the centre (dialogue) speaker.
By sheer fluke, I managed to find a pair of 101/2s up for sale locally (the only ones I’ve seen so far) and managed to get them for £90 – which seemed a good price. I also found a KEF Reference 90c centre speaker on ebay for £65 delivered. I now need to decide on my AV receiver and a HiFi rack (these look nice!), sort out some wall brackets, and ultimately, whether I need a subwoofer or not. If I do, then I hear very good reports about these ones.
So far, between repairs and purchases, the speakers for my fledgling surround system have cost me £235. Admittedly they are not brand-new, or modern “lifestyle” designs, but they are all top quality, full-range speakers that would have cost nearly £1500 when new.
It’s not how I’d originally expected this to work out, but it is proving exceptionally cost-effective!