summing transformer method?

Take a look at this data:

It's apparently a combining transformer for summing two amplifer channels into one subwoofer.

Personally, I never believed bass is completely non-directional. I hear that statement used as an absolute and think nothing is absolute in audio or design. If I used subs I would prefer two, but maybe I don't know what I'm talking about.

I have alot of these devices somewhere in my garage. Are they still useful, or has this method gone completely out of vogue?


more info!

what fun...lost files...

I guess my question should focus on whether this is a respectable technique anymore or if it's a joke compared to anything DIY'ers would do.

Thank you

Oh, in case you're wondering, I am getting fidgety about making room in the garage and basement. Too many projects, not enough room. I have two transformer winder (bobbin & toroid)projects started & really no space left.