Why price of Tannoy speakers from online retailers in UK is cheaper than in US

Freight can’t be cheap either.  Figure that in if buying overseas.

There are hefty duties on speakers!

Around 25% if I recall. Funnily enough, you can ship transducers with little or no import tax. This is why many countries have their own custom cabinet makers and these custom cabinet makers call themselves speaker designers!!! Rather an exaggeration for a bit of woodwork. I believe cabinets can be imported also from China with little or no tax as long as “final assembly” is in the US. So Chinese cabinets and European transducers now make up a large share of “American built” audiophile speakers.

So in addition to added freight cost - import duties play a big role.

Closer to China

Sea freight isn’t actually that expensive. I shipped an suv between the USA and the Mediterranean for $1100. Import tax for goods entering the USA from the UK I am unsure about. But a 6k difference between the UK price and the USA price is a lot. 

And vice versa retailers in US iare cheaper than in UK for gear imported from US to the UK there are dutties and freight costs to be paid.