Being that the Roland DS-50A's are discontinued(at least in the U.S. they are),that would explain why these pieces of garbage are SO overpriced!Since it's exceedingly obvious that you are new to studio monitors,so allow me to make things incredibly easy for you.......avoid the Roland's like the plague,& buy the Adam AX3's right this minute!

It's pretty clear to me that you have no understanding of the specification chart,whatsoever.The Adams have a much broader frequency range in the low end,meaning that the lower numbers(Adam 60Hz vs. Roland's 68Hz),the lower the bass response.
As for the high frequencies,the human audible range is maxed out at around 17kHz,but tweeter ranges beyond this number make for more accuracy and detail within the spectrum of human hearing.That being said,the Adam's tweeters are incredibly more accurate,as the frequency response is more than twice that of Roland's(Adam's 50kHz vs. Roland's 22kHz).

Unlike the Rolands,the Adams are far more well engineered,with serious upgrades in components & materials...providing more overall accuracy,bass,high end detail and with very clean amplifiers with virtually no unwanted noise and minimal harmonic distortion.

Trust me,no one in their right mind would by the Rolands over the Adams...but don't take my word for it.....look around the internet and do the research.

-Elwood