Looking at the data sheet of the MAX4410 headphone driver, lower impedance headphones will get more power.
Is this true in general for laptop headphone drivers? especially with regards to 8-32 ohm impedance ?
Optimal headphone impedance
amplifieraudio
Best Answer
Headphone impedance and anything related is quite complex, since you are normally interested about things like "sound" and "loudness", which are influenced by a lot more than only this single factor. I recommend reading this article on head-fi.org, which sums it up very well.
To get to your question: The output of your headphone jack is controlled by voltage (if you change your computers volume level, you are actually changing the voltage at the headphone jack). So the power your laptop delivers is inversely proportional to the impedance: \$S = U^2/Z\$. That is true if you compare different headphones at the same voltage of your laptop. But normally, you want to compare them at the same loudness, since this is what you as a user normally care about: How loud is the sound that reaches your ears? So this is the point where the headphone´s efficiency comes into play and makes any calculations vain.
A little example: Imagine you have to pair of headphones, one having a low impedance and a high efficiency, the other having a high impedance and a low efficiency. If you take your low-impedance-pairs,they will consume a lot more energy at a set voltage from your source (e.g. laptop) than the high impedance phones. However, you will probably never need to set the same voltage level because of their higher efficiency. They might sound at 30% voltage as loud as the others at 50% or 80%, and then the difference in impedance can´t be compared that easily.
You should also consider, that low-impedance loads usually put larger stress on their amplifier. In the cited Head-Fi.org article, there is a rule of thumb:
Of course, there are a lot more things to considered when buying headphones (like sound quality). I recommend thorougly testing anything your are planning to buy. And, to sum it up: If headphones have a low impedance, they consume more power at the same output level of their input device. That doesn´t say anything about loudness, though.