Reply to Buying another pair of monitors.

So currently I have a pair of KRK Rokit 5's, and a lot of the times when I go play my songs somewhere else it sounds a hell of a lot different. So I was planning on looking for a new pair, particularly the Yamaha HS50's. The question I'm asking, would it be unnecesary to mix those monitors with the KRK? The Rokit 5's have more low end, as with the HS50's they're more mid-high and I personally believe it would be a good. Yet again, I've only been producing for 5 months.