Its not surprising to me you prefer the sound of the crown with the bass percieved as tighter and more controlled. This is due to a lesser understood or talked about specification of audio amplifiers called damping factor. Great explanation of damping factor and how it applies here from yamaha pro audio division
also a general explanation on damping factor on wikipedia
https://en.wikipedia.org/wiki/Damping_factor
TLDR: damping factor is a direct correlation to output impedance of the amplifier and speaker cable. The higher the damping factor the better the amplifier can react to and prevent undesirable cone movement.
To quote the wiki article “In loudspeaker systems, the value of the damping factor between a particular loudspeaker and a particular amplifier describes the ability of the amplifier to control undesirable movement of the speaker cone near the resonant frequency of the speaker system. It is usually used in the context of low-frequency driver behavior, and especially so in the case of electrodynamic drivers, which use a magnetic motor to generate the forces which move the diaphragm”
What does the mean in context of the XTI2002 and NX600?
Ignoring the cable impact for now and just looking at the internal damping factor of each amplifier the NX6000 is rated as DF >148 @8ohm whilst the XTI2002 is rated at >500 @8ohm