Stereo to mono

I am installing speakers outside and want mono to give better sound coverage. To accomplish this would the following work?

Audio source L/R output to RCA splitter (2 female to 1 male) then another RCA splitter (1 female to 2 males) then plug that into the L/R on my amp.

This would give the left and right channels on my amp the same mono input allowing for mono speakers without having to worry about speaker impedance. Does this make sense?!?

I found this device http://www.edcorusa.com/p/5/s2m that will take the stereo to mono and then I can use a Y-connector to take the mono to the left and right channels.