Adding to chrislayeruk's comments; you might want to contemplate home-auditioning a pair of M3100's with your existing 501.

Current price of M3100's is �1,845. Matching stands an extra �330.

When I home auditioned DSP3100's they demonstrated a much louder and clearer improvement over my existing 551/555/A500's.

Not an Actor, nor married to Jamie-Lee Curtis.

#1: DSP5200SE|DSW.2|218|210|506.2|504
#2: Prime/PSU|SOtM sMS-200 Mini NEO SE|Focal Stellia
#3: Other stuff