Considering a Second Subwoofer for the Front

Imagine how a SWARM of these can transform his setup

The recommendations are along my line of thought.  I want the sub to augment my sound.  The current ones are dialed down.  My bucket subs are home depot.  I intend to follow the advice of buying a second salk.  Thanks everyone.  Steve

What is the size of the room?

Have you tested your room for standing waves and whatnot?  What are the existing room treatments?

I would almost always use two front subs, assuming the room allows it, but it all dictated by the space you have to use.

Hasn't Salk closed?

With a four sub array I can't imagine your shooting for stereo. The mono room lock should be amazing. I did it using three different asymmetrically positioned subs and it worked just fine.

If the master sub has remote control volume and the connectivity to daisy chain the other three the system would be conveniently controllable. Good luck with it.