What is the best amplifier for Tannoy Kensington ?

If you are installing an electronic crossover, the answer is you will loose detail in doing so. Bi-wiring is a means of getting speaker cables to sound better, which is why some speakers have the capability.

Well, I was referring to passive bi-amping...

With big Tannoys the crossover frequency is relatively low at 1.1K, so the split -
- % of power delivered to the woofer vs. the tweeter -- is closer to even. Those
Tannoy tweeters have to be designed to handle a high amount of power.

You could argue that because of the close split, you might gain some
"effective" power increase in bi-amping -- but not as much as
investing in a bigger amp (if available; I know of a Kingdom Royal setup bi-
amped with VAC statement 450 monoblocks!). I also wouldn't biamp with 2
dissimilar amps -- the gain matching alone would be a pain, and these aren't
the kind of speaker where you can get away with a much weaker tweeter amp.

Also with a biamp setup, you'll gain some tweeter protection from huge bass
transients that -- when clipped -- would otherwise send peak-power level
high-frequency transients to the tweet. However the woofer would still have
to handle that peak power, the tweets are probably much tougher than usual
anyways, and the tweets themselves are pretty easy to replace.

Also with a biamp setup, you'll gain some tweeter protection from huge bass transients that -- when clipped -- would otherwise send peak-power level high-frequency transients to the tweet.

It should be pointed out that this is only true, to a major degree, if an active crossover is used, ahead of the amplifiers. Which in turn would have significant downsides, particularly in this case as others have pointed out.

In the case of passive biamping, both amplifiers have to swing an output voltage corresponding to the full frequency range of the signal. So in a passively biamped arrangement the likelihood that the high frequency amplifier will be clipped by bass transients will only be reduced (compared to using that amp full range) to the extent that its voltage swing capability increases as a result of the reduction in the amount of current it has to supply, and chances are that increase in voltage swing capability will not be all that great.

I make a point of mentioning this because I have seen many posts here discussing the possibility of passively biamping with a low frequency amplifier having vastly greater power capability than the high frequency amplifier. Which would result in most of the power capability of the low frequency amplifier being unusable, because how much of its power capability could be utilized would be limited by the clipping point of the high frequency amplifier.

Also, as you pointed out, in this particular case the relatively low crossover frequency is an additional reason why a large power disparity between the two amps would not make sense.

Regards,
-- Al

Atamasphere`s suggestion for using one good quality amplifier makes the most sense.Bi amping seems to create potential matching problems that can easily be avoided.
Regards,