How can I come up with comparable efficiency specs for different headphones so I can compare them?
I'm leaning toward the AKG K812 right now. Everything I'm reading says it performs well in just about any setup including a cell phone, so I think it would do just fine connected to my Proton DAC. Plus it doesn't require an adapter for 3.5mm which is what I need for the Proton. Here's a fairly glowing review:
When comparing the AKG K812 to the Sennheiser HD800, they say the HD800 "demands a better amp to blossom". Here's a one-sentence local opinion:
I found this info regarding my DAC:
"Output Impedance Headphone ~ 1 ohm
Edited by headfirocks - 6/21/14 at 1:30pm
Minimum impedance for headphones should be 32 ohms."