Edited by JamyPatch44 - 2/13/17 at 12:16pm
How far away from these screens will you be seating? For proper stereo reception with this setup you'd need at least 1.5m. If you sit much closer, the sound will be coming from left and right with a big gap in the center.
I have a 2-screen setup and the speakers are about 1.3m apart (center-to-center) - this is already too much, unless I kick back an extra half a meter.
Consider getting speakers that will fit under the side screens and angle them up a bit - that would work much better.
This: http://www.amazon.co.uk/Microlabs-MICROLABFC360-Fc360-Speaker/dp/B006812VRA/ref=sr_1_1?ie=UTF8&qid=1398419567&sr=8-1&keywords=microlabs better quality and sound than the logitech 2.1 sets.