If you go straight by specs. The speakers claim 120 watts power handling into 8 ohms. The Rotel pumps out 40 watts. If you can get a neutral enough 100-160 power amplifier, that wont change the sound , you may see some difference. Trying other more Integrated powerful amps also can be an option.
a 40w amp for a 120w speaker def wont do. at low volumes it;ll be fine but once you go higher the amp will not exercise control and there will be distortion. its always best to have a higher powered amp (assuming you wont abuse the speakers with it) to get best SQ