Beyerdynamic DT 990 250 Ohm PRO Studio Mixing Headphones - Newegg.com
Beyerdynamic DT 770 Pro 250 ohm Closed-back Studio Mixing Headphones | Sweetwater
32 ohm vs 250 ohm - Which Headphones Sound Best? - YouTube
Amazon.com: beyerdynamic DT 770 PRO 80 Ohm Over-Ear Studio Headphones in Gray. Enclosed design, wired for professional recording and monitoring : Musical Instruments