Last season I used two speakers on every stand and I think it is well worth doing in big open country. I bought a Foxpro SP-55 speaker to use with my FX5. I bought the SP-55 because I wanted to have more volume. On the first day of using the front speaker on my FX5 and the external SP-55 speaker, I realized how great it was going to be having two speakers to point in the two directions I wanted to point them in. I call off of ridge tops quite a bit and I used to point my speaker down the ridge and hoped that the sounds went into both canyons on each side of the ridge I was calling from. With two speakers and being able to point them where ever I want, it helps spread the sound out to a wider area.
In the above picture this is how the caller and speaker were set up when I got this coyote.
In this picture I was on a rocky ridge with wide open country for miles about 180 degrees out in front of me. This picture is exactly how the call and speaker was when I called in this coyote. I don't mind carrying a little extra weight because I am confident it gets me a few more coyotes in the long run.