What is Headphone Impedance? [Definitive Guide] - Home Studio Basics
Amazon.com: beyerdynamic DT 770 M 80 Ohm Over-Ear-Monitor Headphones in black, closed design, wired, volume control for drummers and sound engineers FOH : Musical Instruments
Headphone buyers: Here's what you need to know about low- vs. high-impedance models - CNET