Bi-amping Revel Gems with a tube integrated amp

Hey guys,

I was wondering if I would see much bennifit to bi-amping my Revel Gems by adding a tube integrated amp. Here is my current setup:

Placette passive linestage
Krell 400CX amp (output 1 from placette)
Revel Gems
Revel B15 (output 2 from placette)

So my thoughts would be to Y output 1 of the placette into the Krell and a tube integrated amp. Then I assume I could balance the different gains of the amplifiers using the volume on the tube integrated amp. Could I just use an SPL meter and adjust the tube amp until a freq level in the tweeter level match a freq level in the midrange? Would the gain of each amp be linear? So once I set the tube volume I would never have to adjust it again?

Would adding a tube amp to just the tweeter make a difference? I mean I've heard solidstate is better for bass right? But is it more for low bass and not as much for midrange.

I know the bi-amping topic has been discussed a lot, any thoughts would be great.

Thanks,
Russ