Rental comp calculation

[Dave Schimmels]

What is a good way to get accurate rent comps with existing tenants based on the area? I have a duplex in cleveland with a combined 2,336 sq. ft. Are the comps from the Bigger Pockets per unit figures? Each unit is $725. I feel I'm on the low end, but my COC return a year later is roughly 14%. I've been updating things that need it and lucky enough, I can do the work myself to keep cost down for now, only because it be my first rental.

any advise would be much appreciated. 

Thanks