Sony MDR-7506 vs Sennheiser HD 280 PRO vs Audio-Technica ATH-M40x Headphones

Comparing popular pro neutral balanced $100 headphones. They are all dynamic, closed-back headphones and are being reviewed from the point of view of recording and mixing audio. Also, do headphones degrade after 20 years? Yes, they do. TIME CODES 00:00 Intro 02:50 Gut Conclusions 04:01 Sony MDR-7506 in detail 06:42 Audio Frequencies 20 Hz to 20 kHz Explained 07:09 Sennheiser HD 280 PRO in detail 09:46 Audio-Technica ATH-M40x in detail 12:16 More Detailed Conclusions 13:17 New vs 20 Year Old Sony MDR-7506 #audiotechnica