The AH-MM400 is an excellent pair of reference headphones that are designed to be the best sounding headphones you can buy at that price point. The AH-GC20 at the same price point is designed for travel, with active noise cancelling and Bluetooth for the best travel experience.
If you simply want the best sounding headphones, you want the AH-MM400. But if you travel a lot, the portability of the AH-GC20, along with the wireless option, and active noise cancelling probably make it the best choice. And let me be clear, the sound quality is superb and will not disappoint.
I hope this helps. Thanks!
Date published: 2016-09-09