Me x3
Member of the Trade: FiiO Store Argentina
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- Nov 22, 2012
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Hi! Thanks for the info.
I have found impedance plots against freq for T1 but was curious how I can see the efficiency of T1. Is there an efficiency-frequency plot somewhere? Or is it because of the Ohm's Law justification?
Thanks!
Yes, the Ohm's law justification is fine. Add the frequency response plot (FR), and that's it.
http://www.innerfidelity.com/images/BeyerdynamicT1SN3964.pdf
As you can see, the headphone sounds similarly loud at 100Hz and 1000Hz.
From headphone.com link
"To perform this test (FR) we drive the headphones with a series of 200 tones at the same voltage and of ever increasing frequency. We then measure the output at each frequency through the ears of the highly-specialized (and pricey!) Head Acoustics microphone."
Mix the two plots (impedance and FR) + the Ohm's law justification and problem solved.
You can think the headphone as totally flat for the sake of simplicity. Then:
1 Vrms @ 100 Hz sounds just as loud as 1 Vrms @ 1000 Hz
But it's a 1300 Ohm load at 100 Hz and 600 Ohm load at 1000 Hz
Ohm's law -----> The headphone needs less power at 100 Hz
(ie, it's more efficient at 100 Hz)