Golden Ears Test System - for more information (Link)
1. HATS: Bruel & Kjær - Head and Torso Simulator Type 4128C
2. Microphone Amplifier: Bruel & Kjær - NEXUS Conditioning Amplifier 
3. Audio Interface: Lynx L22
4. DAC: Golden Ears D/A Converter
5. Headphone Amplifier: Golden Ears Headphone Amplifier 

How we test
1. Headphone / Earphone
2. Speaker
3. Amplifier / DAP
 
How to read G.E. Graph
1. Earphone / Headphone
2. Speaker (Directivity Pattern)
3. DAP / Amplifier