I have some Sony MDR-V6s and AKG K550's. Here are the ratings:
114 dB SPL/V
So, first question is what is the difference between SPL/V and dB/mW?
Second, it seems to me the AKGs should be more efficient and sound louder at the same volume setting from my amp, but the that is not the case. When I use the Sony's Ihave to turn down the amp by about 10 db to feel like I have the same volume. In other works the Sony's seem way more efficient.
Can anyone educate me?