Krell 450mcx mono/subwoofer connection

Krell equipment.  I love my big iron
I have mono amps 450 MCX pr  
KCT Preamp KPS28    CD
B & W 803. With The One cables biwired
PBN Grovemaster turntable w  two Liberty audio   B2b1 phono stages  Set in balanced mono        operation
Cast thru-out

Can I piggy back the speaker out of the 450mcx  R& L straight into the speaker imputs of a subwoofer. I was thinking one larger sub. Or two smaller ones ,one each   B&W
I was thinking Rel. or Vendolyne
I am unclear if the amplified 450 MCX  signal would effect the  amp inside the subwoofer