l would characterize me as normal volume listener. I honestly do not follow the ZX300 thread, as I have the real deal already. And you never know the history of peoples ears. I did not attend too many live rock concerts and also do not listen to EDM or Metal. I am a long time Bob Dylan fan. He doesn't make you deaf. So my ears are quite intact. The WM1A is worth a try, that's for sure. I am curious about the HD820. They come with a 4.4mm cable, so I will walk to my dealership and give them a run from the WM1A. I am not afraid of the 300 Ohms. I had a HD800 for some month, I ran them from my EU capped ZX1. It was ok, but I needed something between 85 and 100%. Let me report how I find the HD660S from the ZX1.