The lowest phones I have are Senn HD212pro's. They are 32ohms. They have tons of bass by nature, so I tried them last night. Wow, they sound great considering the "excess bass". I could drive them right up to pain if I wanted too. So far, I'd have to say the Zero unit doesn't care what phones you use. It has plenty of power to drive any of them. No added hiss or distortions either. Have a good one!!
