Thanks for the responses. Not quite clear about the explanations. I should probably explain the issue I'm having - I have a pair of Senheisser HD650 cans that are rated at 300ohms. I have Logitech Z5450 speaker which I sometimes listen to through my headphones.
The problem is I have the volume turned all the way up and it's not loud enough (sound is about average volume but not loud enough for me) through the headphones. Its probably because the Z5450 has a crappy amp for the headphone jack (even my iPhone is louder at higher volumes).
So presumbly I need a headphone amp to boost the volumes. And I'm trying to figure the proper impedence I would need on the amp. The nominal impedence on the z5450 is in the 1000s. But this won't drive those headphones.
So going back to my original question I am confused about how impedence is measured? Speakers in general are rated in single digit ohms. My headphones are rated at 300ohms. My speakers nominal impedence is rated in 1000s. Why is the metric so vastly different for different devices?
