Denon/Marantz come from the same stable, Sennheiser not related. My guess is that they choose not to go because they feel their marketing budgets can be spent more effectively elsewhere. To my knowledge both the companies don't show at any UK exhibitions.
In my experience bi-wire is beneficial where a speaker designer has included the feature as the cross over is optimised to operate at its best in bi wire mode. Bi-wiring is beneficial as it minimised back EMF.
http://en.wikipedia.org/wiki/Counter-electromotive_force...
Tannoy, NAD both were exhibiting, Tannoy with Icon and NAD with Armour but you'd struggle to find them - did you read the show guide? They are both listed.
I visited the show this morning. £15 to get in!
Smaller and less exhibitors than last year.
Many big names missing.
Not enough exhibitors, especially in the Stuff area.
Come on Haymarket you must be able to do better!
Does anyone else have a view?