Kevinzoe
It would be ideal to have Mono amps to drive each driver to each speaker.That being said it is also very expensive using world class amps plus the active crossover.If you have the $$ go for it.
You would be taking the drag out of an amp being used to compensate for 2-3 driver's.
Using an outboard active XO you are bypassing the internal XO within the speaker unless you use that same XO and reconfigure it to add Pots and circuits for adjusting for output.There is no use for it.Wth an Active XO you would using control pots to compensate for how much power is being used for each driver.
Believe me I am new to the equation also,but it is what pro's are going into now.One I read recently does not see buying any speaker over $500 without it having an outboard active XO.
SET's are not ideal amps to use in this configuration as someone had mentioned.I think a Dual Mono amp might suffice instead of Monoblocks to save space and get the same results.
You have to look at the driver efficientcy also.Tweeter's might not need 300watt amps unless you are driving the Mids\Tweeters with the same amp or going the vertical route.
I am in the process of getting my speaker's and will know more then.It shall be intresting.
The thing to remember about which ever way you decide to amp is that you are freeing up watts so that the driver's can be driven more efficiently.Weather going Vert or Horz brings about better sound has alot to do with a number of factor's.
In the final analysis you will be getting better results because you are freeing up the power to be dedicated to individual driver's.
What drives me nuts is what amps I should use to get the best performance.I have 2 B&K's and it might be wise to use the same Manf..I would only use B&K's that have been modified though ,so that brings up cost.I might use a Adcom,McCormick for Bass and B&ks for the Mids and Tweeter's.Class A or A\AB amps that are biasd to run closer to ClassA are the best amps to use in any situation.Monarchy and Black Knight amps are good choices.Then you get into Krell territory which gets to be ultra expensive.Some even use Bryston amps.SO you have to do some research.
KEF I believe is well aware of these things and and give you the option tp add an outboard XO at a later time .So I would consult with them to see what they have had good experience with or other KEF owner's also.I think that's what your speaker's are.
I found this all confusing at first myself and it will be experimentation till I get it all set up,but there are advantages to doing it.I am a purist and this seems a step in that direction from everything I have been told.It was the original designer of my speaker's that got me intrested in this trend and he is very knowledgeable.
Hope that helps!
