Let’s take a look at the HIFIMAN HE400S headphones. Really solid pair of cans, these - open-back, comfy earcups, punchy bass, and a planar diaphragm that means you get some gorgeous detail in the sound. They are, by any stretch of the imagination, a superb pair of headphones - so much so that they made it into our 2016 roundup of the best over-ear headphones in the world. They also contain a little piece of marketing information that is complete and utter nonsense.
Navigate over to their page at the HIFIMAN website, and you’ll see, as you might expect, a list of tech specs. And right at the top of that list is the headphones’ frequency response, which is listed as 20Hz-35kHz. Which is impressive, until you realise that HIFIMAN are trying to sell you headphones that can produce sounds inaudible to humans.
Here’s a little primer on frequency. Any sound you’ve ever heard has a pitch, from a Skrillex bassline to a violin note. We’ve got ways to describe that pitch in everyday life - high and low. A bassline has a low pitch, and the violin has a high one. Scientifically, pitch is measured using Hertz (Hz). A bassline probably pops up at between 20 and 100 Hz, while the violin makes its appearance at around 17,000 Hz (the correct way to refer to it is actually 17 kiloHertz, or 17kHz). Your voice is probably in the range of 85-255Hz. Any given sound will actually have a bunch of frequencies mixed into it, but they’ll all occupy a fairly limited range.
When a headphone manufacturer talks about frequency range or frequency response, they’re talking about the frequencies their cans can reproduce. So a pair of headphones with a range of 20Hz - 20kHz can playback any sound in that range, which more than covers the sounds humans can hear. We actually can’t hear anything above 20kHz.
So you might be asking: why does HIFIMAN bother making headphones that go up a full 15,000 Hz over what anyone who listens to them can actually hear?
Our argument isn’t that HIFIMAN, and anyone else, should stop doing this. In making a superior pair of headphones, they will inevitably create something that is capable of producing these frequencies. Our argument is that they should stop listing it.
Seriously - stop even using it as a tech spec. It’s becoming completely meaningless in 90% of all audio equipment. Nobody who buys these things is actually sitting there with an equaliser to check out the frequencies. Very few people can actually tell the difference between 19kHz and 20kHz. It’s a spec that has become completely divorced from any use it might have, and occasionally it drops into really dumb territory. There are otherwise fantastic headphone amps, like the Brainwavz AP001, that boast an ability to handle frequencies up to 100kHz. That’s a frequency audible to bottlenose dolphins, porpoises, and nothing else. That is deeply moronic.
We’re guilty of this too. Our specs tables regularly list frequency ranges for products, and it’s time to face up to the fact that it’s a completely useless piece of information to almost everyone. So from now on, unless there’s a really good reason to mention it, we won’t. We’ll also be working on correcting the existing tables on the site to remove it where appropriate. Our plea to audio companies is to bury the damn thing. Yeah, we know it has to be listed somewhere, but you guys have got to stop giving it top billing.
And if you see a nice, high-looking frequency range on your next pair of headphones, just ignore it.