You'll need x-over for horizontal.More power from vertical as usual the power is doubled whereas horizontal is 150%.But if your not real power hungry speaker wise bi-amp can be nie.Been wanting my buddy to bi-amp his Maggie/Bryton combo with their nice x-over and a second 4 BST.I think an 89db+ speaker (say a pair or Merlins) would do nic with ll tube with VTL integrated,matching power amp (not enough companies offer matching power amps for their integrateds I think) with a Marchand tube x-over would be great and a value for what you get.But in main mono vertical way to go.Check the thread.
Cheers
Chazz
Cheers
Chazz