IMO any room for sound reproduction will improve dramatically with corner absorption (traps). Most basic I can think of. Also most cost effective
Universal room treatments
I’d like to know if there are room treatments that almost all rooms need for optimum sound. I am moving a not picked out yet system into a dedicated room ( 14 x20 x 7 ft room) with carpeting , concrete floor and no windows. What treatments are essential even before I purchase any speakers etc. In other words, are there basic treatments I should do before any components are purchased? Than you in advance.