hi,
how you can see in my setup that I have two BL7.4. Left and right.
I splitted the stereo powerlink signal from my BVE with a special splitter cable for the left and the right side.
You cant hear a stereo signal from only one BL7.4 speaker. The BL7.4 was to build as a center speaker for BV7
In my setup that works pretty good but the opinion are divided here.
It is up to you to try something out.