[Conway Morning]

Hi, so I'm looking to buy some new headphones and so I find some that I like here http://www.skullcand...es-c-42_57.html

Here's what I don't understand.

# 50mm speaker
# Frequency range: 100 – 18,000 Hz
# Impedance: 32 ohms
# Max input power: 100mW

what do these mean ??? and also I noticed that a similar pair of headphones had a "40mm" http://www.skullcand...hop/ti-p-7.html
so is that better or worse ???

Would someone please explain this to me as I am very confused help would be greatly appreciated!

Thanks,