The Frequency Spectrum: What Lives Where, and What Happens When You Move It

Every EQ tutorial hands you the same chart: sub-bass, bass, low mids, mids, high mids, presence, air, with frequency ranges attached. It is accurate and it is nearly useless on its own, because knowing that the low mids run from 250 to 500 Hz does not tell you what to do when a mix sounds wrong.

What makes the spectrum usable is knowing what is actually in each region on a real track, and — the part almost nobody covers — what happens to all of it when an edit moves everything at once. A slowed or sped-up track does not just change tempo. It relocates every instrument on this map.

1. The Bands at a Glance

Here is the whole map in one place. Every boundary below is a convention rather than a fact about physics — the spectrum is continuous and the bands blend into each other — but the vocabulary is what lets you locate a problem quickly instead of adjusting at random.

Sub-bass — below about 60 Hz

Felt more than heard. 808s, the lowest kick and bass fundamentals. Most small speakers cannot reproduce it at all.

Bass — roughly 60 to 250 Hz

Weight and power. Bass guitar and synth bass fundamentals, the body of a kick, and the fundamental of a low male voice.

Low mids — 250 to 500 Hz

Where congestion accumulates. Almost every instrument has energy here, so the sum piles up even when no single part is wrong.

Mids and high mids — 500 Hz to 4 kHz

Identity and intelligibility. The range human hearing is most sensitive to, because it is the range speech uses.

Presence and air — 4 kHz and above

Detail, transients, and openness. Almost no fundamentals live here — it is harmonics, cymbal attack, sibilance, and the sense of space around a recording.

2. Sub-Bass: Below About 60 Hz

This is the region you feel more than you hear. The lowest note on a standard four-string bass guitar sits around 41 Hz; a kick drum's fundamental is often in the 40 to 60 Hz region; an 808 lives here almost entirely.

3. Bass: Roughly 60 to 250 Hz

This is where a track's weight and power live. Bass guitar and synth bass fundamentals occupy most of it, and the body of a kick drum sits in the lower half.

4. Low Mids: 250 to 500 Hz, Where Mud Lives

If a mix sounds cluttered, congested, or boxy, this band is the first place to look — and there is a structural reason why.

5. Mids and High Mids: 500 Hz to 4 kHz

This is where the ear is most sensitive, and it is not a coincidence — it is the range human speech uses, and our hearing evolved around it.

6. Presence and Air: 4 kHz and Above

Above about 4 kHz there are few fundamentals left. This range is almost entirely harmonics, transients, and noise.

7. What Happens When You Move All of It

Now the part the standard chart never covers, and the reason this matters on a site about slowed and sped-up edits.

Varispeed multiplies every frequency by the same factor. It does not shift the spectrum along by a fixed number of hertz; it scales it. So an edit does not merely sound slower or faster — every instrument moves to a different place on the map above, and the ratios between them are preserved while their absolute positions are not.

Slow a track to 0.85x and a 60 Hz kick fundamental becomes 51 Hz, moving from bass toward the sub-bass region that small speakers cannot reproduce. A vocal fundamental at 150 Hz drops to about 128 Hz. Everything gets heavier, and some of the weight relocates to where it may not be audible on the listener's device.

Speed a track to 1.5x and the same kick moves from 60 Hz to 90 Hz — out of the region that gives it physical impact and into one where it reads as a click rather than a thud. This is the mechanism behind nightcore edits sounding thin. It is not that the bass was removed; it is that the bass moved somewhere it no longer functions as bass.

7a. What Follows From That

Two practical consequences, both of which explain choices you have probably seen without knowing why.

First, sped-up edits benefit from a bass boost, and this is why nightcore presets routinely include one. It is not a stylistic flourish; it is compensation for the fundamental frequencies having vacated the range that provides weight.

Second, fixed-frequency processing does not follow the music. A shelf at 150 Hz stays at 150 Hz regardless of what speed you set, but the content it was aimed at has moved. If you dial in a bass boost at normal speed and then slow the track down, the boost is now catching different material than it was — usually more of it, since content that sat above the corner has descended below it. Set the speed first and judge the tone afterwards; doing it the other way round means re-doing it.

A Note on What These Numbers Are

Every boundary in this post is a convention, not a fact about physics. The spectrum is continuous, the bands blend into each other, and different sources will give you 250 Hz where this one gives 300. Nothing changes at a boundary.

The values that are genuinely fixed are the specific ones: the lowest note on a bass guitar really is about 41 Hz, and this site's low shelf really does sit at 150 Hz. The band names are a vocabulary for talking about regions, and their usefulness is entirely in helping you locate a problem quickly rather than in their precision.

The Short Version

Weight lives below 250 Hz, congestion accumulates from 250 to 500, identity and intelligibility sit from 500 Hz to 4 kHz, and detail and air live above that. Boost the wrong band and you get boom, mud, harshness, or sibilance — each a specific and locatable failure rather than a general badness.

And when you change a track's speed, all of it moves. That single fact explains why sped-up edits sound thin, why slowed edits need less bass than people add, and why the order you make your adjustments in matters. Try moving one band at a time on something you know well — it is the fastest way to attach these numbers to sounds.