So I have a Sennheiser HD 280 PRO headphones. These headphones have an impedance of 64 ohms. They sound great.
I also have a Sennheiser HMD 280 PRO headset (notice the M, means with a microphone). They look and feel almost exactly the same as the HD 280s, except they have a microphone. These however, have an impedance of 300 ohms.
Both of these get plugged into a headphone distribution amp to get sound from a single source. What I've noticed is that I have to turn the amp up to 100% on the 300 ohm headset in order to hear the same level of sound that only requires the amp turned up to 60% on the 64 ohm headphones.
My question... why would I ever want a 300 ohm headset, over something with lower ohms?
I'm looking to get some Sennheiser HMD 26-II headsets, and they come in both a 600 ohm and 100 ohm variant. Why would I ever want the 600 ohm variant if it requires me to jack my amps up so high? Jacking my amps up also jacks up any sort of electrical noise and interference in my lines.