Linn amps + Mapletree pre - through Linn Sizmik ?

I am running a pair of Linn LK140's (active) with a Mapletree Ultra 4SE pre-amp. Speakers are Katan's and also have a 10.45 Sizmik. Initial results w/o the sub are pretty darn good ... however, I now am trying to include the Sizmik subwoofer in the mix and wanted to confirm the correct wiring path.

Should I: Daisy chain the two LK140s, then run the lower frequency LK140 into the Sizmik via the HP filter input?

Then, out of the Sizmik and into the Mapletree pre-out ?

Just want to do it correctly... as I understand running it thru the Sizmik limits the low frequency info going to the Katans.

I was concerned with possible impedance matching issues between the amps and tube pre, but so far sounds great. Once I throw the sub into the mix though I might run into some ... will advise on the result.

Any assistance or counsel as always - greatly appreciated!