Headphone specs always say something like "20 Hz – 20,000 Hz" and it looks important. And sure, it kind of is. But it's nowhere near as simple as manufacturers would like you to believe.
Let's break it down.
What does frequency response mean?
Frequency response tells you the range of sounds a pair of headphones can reproduce. The human ear hears roughly from 20 Hz to 20,000 Hz – from deep rumble to high-pitched hissing. 20 Hz is that feeling when the bass rattles your chest. 20,000 Hz is the sound you can maybe still hear if you're 15 years old and haven't been to too many concerts.
When a manufacturer states a frequency response of 20–20,000 Hz, it basically means: "These reproduce everything your ears can hear." And this is where the problem begins.
Why the number alone tells you nothing
Almost all headphones – including those €15 earbuds from the petrol station shelf – claim a frequency response of 20–20,000 Hz. That's a bit like a car listing saying "car has engine". Technically true, but doesn't tell you whether it drives like Henri's Alfa Romeo (badly and unpredictably) or like Raimo's W124 (smoothly and forever).
What matters isn't the range but how evenly the headphones reproduce sounds across that range. This is illustrated by a frequency response graph – a curve that shows how loud each frequency plays. A flat curve means no frequency screams over the others and nothing goes missing.
Cheap headphones often artificially boost bass and treble because it sounds "wow" at first listen. After five minutes your ears are fatigued and the music sounds like it's being played out of a bucket.
How Valco does it
Jasse – our sound engineer whose ears are insured (this is not a joke, well okay, maybe it is a little) – tunes the frequency response of every Valco headphone model by hand. The goal is a balanced, natural sound where the bass is solid but not muddy, the midrange is clear, and the treble is bright without being piercing.
With the VMK25.2 and NL25 you can also tweak the EQ yourself via the app, if your taste differs from Jasse's vision. He won't take it personally. Or he will, but he'll get over it.
What to remember from all this
When comparing headphones, don't just stare at the frequency response range in the specs. It's a marketing number. Look at reviews instead, listen for yourself if possible, and remember that a flat frequency response is generally better than an artificially pumped one.
And if some manufacturer claims a frequency response of 5 Hz – 40,000 Hz, it sounds impressive. You just can't hear those frequencies. Maybe your dog can. But your dog isn't paying for the headphones.
Every Valco headphone is tuned so that music sounds the way it's supposed to sound. And every purchase funds 0.000001% of our Death Star. Thanks for that.