If you are looking for the perfect headphones on the internet, you will frequently find recommendations like: more is always better. But this does definitively not work for every kind of use.
According to the impedance of an amps’ speaker, the impedance of headphones will have to be matched to the respective usage. In some cases, high-impedance headphones can be the wrong choice.
Unfortunately, the outputs for headphones are not standardized. Therefore, mismatches are almost the usual situation. While your tube amp mostly allows to choose between outputs or speakers with 4, 8 or 16 ohms, it is much more difficult to do so with headphones.
And for headphones are actually nothing more than little speakers, amplified by a small amp, this fact will definitively have an effect on the whole sound.
But not only the volume will be affected by the impedance, the resolution and thereby the sound varies according to the respective values.
Attention should be paid to the fact, that high-impedance headphones, for example with 250 or even 600 ohms need a preamp. MP3 players, soundcards and small hi-fi systems do not provide enough power to run these headphones.
Areas of application
The comparison of headphones with an identical construction but varying impedances are pretty complicated in layman’s terms.
While headphones with a low ohm value might sound really nice in combination with a laptop or a MP3 player, high-impedance headphones will be far too softly.
Comparing both in combination with a hi-fi sound system with an integrated high-quality headphone amplifier, the high-impedance headphones will sound much nicer because they have been designed for applications like these.
Headphones with low ohm values might overdrive in this case.
In doubt, I would always choose headphones with a lower ohm value because it is much more flexible.
In practice, you will not benefit from the fact, that you own 600 ohms studio headphones which is unable to exploit its full potential in combination with your MP3 player.
In combination with your individual setup, the sound of certain headphones can be quite different to the sound of the sound you perceived while trying them at the music shop. In the showroom, the high-impedance headphones might have provided a rich sound, while at home they might overemphasize the upper mids.
Last but not least
The headphone amplifier is at least as important as the headphones themselves. And it would be wrong to say, that it might be a good option to buy headphones with the highest impedance and combine it to a cheap amplifier.
In the end, the individual taste is what matters.
For those who want to check this out in detail, but who do not know the exact technical values of his/her own hi-fi system, it can be pretty helpful to compare two pairs of headphones with different ohm values combined with the device you will mostly use them with.