Custom sub integrator

As some may remember, having a combined HT and 2 Channel system made me decide to dedicate my sub to the HT.  The HT L/R out feed my Luxman integrated using bypass mode.

I've decided to build a sub integrator however with the following features:

• Works off the 12V trigger from the HT receiver
• Switches input from HT to Luxman preamp section
• Provides 70 Hz high pass filter for either input
• Provides full-range sub out

There's more to it though, I'll be using a miniDSP on the subwoofer, and I'll be plugging my 2-way main speakers to turn them into sealed boxes. 

I'll let you know how well it works out!