Hold on now, kids ....... The XM4 is only 150watts at 4 ohms, and is NOT designed to run at 2 ohms. It's probably over 5 years old, and only listed at $399 when it was new. That unit (if perfect) would only be worth $75-100 bucks today. (tops)
Everyone, and everything I listen to is my teacher. Every instrument, every voice, every sound in nature ... they are all my private tutor ... 24/7 for free.