Subwoofer query

[Unclemonty]

Hi - is anyone here using a Expert with a subwoofer AND a AV receiver? I'm after some connection advice as to whether my preferred connection method will work, or if there's a better way of doing this. 

I'm about to buy a JL Audio e110 or f112 subwoofer (doesn't have many inputs) & was planning to connect in this way:

1) when playing music, Devialet sums the L & R channels to a single subwoofer output which connects to a line in on the subwoofer

2) when using the home cinema receiver, I use the bypass facility in the Devialet. For this input I don't wish any subwoofer output from the Devialet but instead want the receiver to send LFE to the other input on the sub.

I am trying to connect two different sources of bass into a single subwoofer - one from my Devialet and one from my receiver. 

Just wondered if anyone here does something similar or has a better idea for how to connect Devialet + receiver + sub?

Thanks in advance!