Bi amping and cabling

I have two Carver amps that I use to Bi amp my NHT 2.9's. The question I have is what is the proper way to split the signal coming from the pre amp and deliver the left and right channels to both amps. I am currently using some simple "off the shelf" Y splitters. What should I be using and should these be customs made? It doesn't make sense to use a 1 meter pair for a relatively short interconnect.
Zimmerma, Thanks for the reply. I assume the active crossovers duties would be to roll off the bass or treble output. Would this go into the system after the pre amp and before the respective amps, or would this be placed after the amps prior to the speaker connection?. Where would you get such a device?
I actively biamp. In my system, the crossover has a pair of interconnects from the preamp to the crossover. From the crossover, there are two pairs on interconnects to the amps. You can get active crossovers from Marchand, Bryston among others (do a search and there is plenty information about this.)

Good luck,

I would recommend the Bryston 10B active crossover.Look for a used one in Audiogon sometimes under "tweeks" or "miscellaneous EQ".Expect to pay around $900 depending on condition.At least that's the round figure I've seen them sell.