Hey all,
I own Beyerdynamic 990's and am considering buying an amp for them.
But the Engineer in me is bothered... Why should high impedance phones need a bigger amp?
I can see that you need more voltage for a given volume level. P = V^2 / R so twice the impedance requires sqrt(2) more voltage. I can see that you might clip you amp before the phones were loud enough.
However, if my current amp is loud enough for me, what does a better amp buy?
With speakers, it is low impedance, and reactive impedance that is the problem. Driving low impedance requires more current, and that requires a bigger power supply. A reactive impedance also requires an amp with lots of reserve power. It is easy to understand how a reactive electrostatic or 2 ohm ribbon loudspeaker benefit from a heavy duty amp.
However, a high impedance headphone is not very reactive, and does not require large amounts of current-- in fact they need less current for the same volume level.
I feel like 600ohm phones should be easier to drive. What am I missing?
Thanks in advance
P
