Perfect sound balancing tool, match your sound to the venue very quickly.
I use this between my Mackie mix 5 and my E400 t, amp, hi & lo outs of my Rolls, into the 2 stereo channels of the E400, one E400 out goes into a massive, passive 18" reflex bass cab, the other E400 out, goes into a passive 10" with horn. I'm solo & looper, doing medium rock to regae from last 50 years. I have a destinctly mono sound without any effects. My sound is clean and powerful enough for big & busy bars. The Rolls really kicks up the ability to "make them have it". A great little tool.
I must mention that the other main "out" of the Mackie mixer goes to my active monitor.