Bi-amping Avantgarde Duo's

Has anyone tried bi-amping Avantgarde Duo's ? My gut feeling is it probably wouldn't be worthwhile but you never know? How about mixing solid state for bass and tube for the mid/tweeter horns?

Additionally, what are the audible differences with feeding a line level signal to the bass speaker unit compared to using the amplified output which I guess most of us use?
Isn't that how the speaker already works? I mean that the woofs are 'self powered' with a solid state amp built in and the mid-tweets can be hooked up to anything, but often (and in my case, hardly unusual) it is with a tube amp.
The idea of feeding the woofers from the speaker level signal rather than line level is, I think, to impart the same sonic signature, and overall amplifier behavior of the mid-tweet amp to the woofers, for more coherence.
I have thought about trying the line level inputs to the woofs a few times, but never bothered doing it.
I'd be interested in other responses.
Whart is essentially correct.

Avantgardes have been criticized for the bass not blending well with the mid horn. Some of us know that can be pretty much a non-issue with careful voicing.

Using the line level input makes it all that much more difficult to get a satisfactory blend.
hey, Jim, howz it hangin?
My Duos sing with the Lamm amps.
And my bass integration problem is not a problem anymore (the Lamms go down way deep for a tube amp). I switched to Joe Kubala's cable, and went to long ic/short speaker runs. Took out all power conditioning, going straight into the wall.
System is really enjoyable, and most recently stuck some NOS Tele's in the 6922 sockets of the Steelhead. Big improvement over the Mullard NOS. The system sounds 'true.'

Be well.