Gary,
I have since spoken to the dealer who did the original demo. They confirmed that their Sizmik was definitely faulty and are waiting for another one to arrive.
Since then, my reservations over spending a grand on a subwoofer overcame my desire for perfection. As a result I explored the less expensive sub options on the basis that - since two good subs are generally considered to be better than one great one - I could spend around £500 and get one now and another later if need be. During my Sizmik audition I discussed cheaper options with the dealer and was recommended the Yamaha YST-SW320 at £350. I dismissed it at the time because, according to the Yamaha literature, it was only available in black (you'll remember I'm looking for a cherry veneer sub to match my other speakers and furniture). Further investigation revealed that 1) there is a cherry option which is available on the continent but not in the UK, and 2) What HiFi did a mid-priced subwoofer group test (Feb '01 issue) in which the YST-SW320 trounced the competition. Since £350 was a little less than I had wanted to spend I looked at the rest of the Yamaha sub range and found that the SW320 had a big brother: the SW800. This is very similar in design but has over 3x the power at 800W RMS (!!) and a retail price of £500 - just right for my new and sensible budget. A search of the internet revealed a German website which could supply the SW800 in cherry for DM1059 (about £340) delivered! Being power-crazed AND a sucker for a bargain, I was entirely unable to resist. So I've ordered one without either autioning or reading a review of it. I figure that, in the unlikely event of my hating it when it arrives, I'll be able to sell it on without making a loss. On the other hand, if it's as good or better than its little brother, I'll be able to buy a second one for a grand total of less than £700. Have I done a bad thing?
As if not auditioning it is bad enough, the company selling it (electronica34.de) do not accept credit cards so I will have to make an electronic transfer of funds once it arrives in stock. I'm told (not by them) that this is very common in Germany and they do seem quite reputable so I have decided it's a risk worth taking.
If anyone else has any experience or has seen reviews of the Yamaha YST-SW800 sub I would be very keen to hear about it before I part with my cash.
Simon