Guides

Best Speed for Slowed and Reverb: 0.75x, 0.80x, 0.85x or 0.90x?

2026-10-11

What each speed does to pitch and tempo, the semitone and BPM math behind it, which genres suit which speed, and a ten-second test for picking the right one on any song.

Speed is the first decision in a slowed edit and the one that is hardest to undo, because everything after it, the reverb tail, the bass, the way the vocal sits, depends on where the tempo and pitch landed. Reverb at 40% sounds one way at 0.90x and quite another at 0.75x.

Most edits you hear online live between 0.80x and 0.88x, and the arguments about which is "correct" are mostly arguments about taste. But there is real reasoning underneath. This guide gives you the numbers behind each common speed, the music theory in plain terms, and a decision method that takes about ten seconds per song. The speed control in the free slow down song tool goes from 0.50x to 1.50x; here we care about the slice from 0.72x to 0.92x. If you want to go deeper than that, the slower and deeper page covers the extreme end.

What speed actually changes

With Preserve pitch off, which is how slowed + reverb is made, speed changes two things at once in a fixed relationship:

1. Tempo. A 100 BPM song at 0.85x is 85 BPM. Simple multiplication.
2. Pitch. Every frequency is multiplied by the same factor. Pitch is logarithmic, so the semitone shift is 12 times the base-2 logarithm of the speed. 0.85x works out to about 2.8 semitones down.

The second point explains why slowing feels like more than a tempo change. Three semitones is a major or minor third. A song in C now sounds like it is in A. The vocal is in a different part of the singer's range and the chords have a different weight.

The four common speeds

And the in-between values people actually use:

0.90x: the light touch

At 0.90x the song is recognisably itself with a slightly heavier feel. Vocals stay in their natural range. Fast songs, 140 BPM and above, often sound best here because they have tempo to spare. It is also the speed to use when the vocal is already low, or when the lyrics are dense. The downside is that with modest reverb, 0.90x can sound like a slightly off-speed copy rather than a deliberate edit. Give it 45% Reverb and a 3 s Space and it reads as intentional.

0.85x: the standard

This is the speed most people mean when they say slowed + reverb. About three semitones down, 15% slower. It is deep enough to change the mood of almost any song and shallow enough that vocals survive. The Haze Chamber preset uses it. If you are building a channel and want one speed for everything, this is the one.

0.80x: deep

Four semitones down and a fifth slower. Sparse arrangements, instrumentals and songs with a lot of sustained pads become huge here. Vocal songs are a gamble: high, airy voices gain a lot of warmth, mid and low voices start to blur. The beat loses snap; a tight trap hi-hat pattern at 0.80x becomes a lazy shuffle, which is sometimes exactly the point.

0.75x: very deep

Five semitones is almost a fourth. The song is a quarter slower and a different piece of music. Most vocals stop sounding like a person singing and become part of the texture, which works for ambient and lo-fi treatments and almost nothing else. Drums lose their transient entirely. Reverb at this speed needs a long Space, 4 to 5 s, or the gaps between hits feel empty.

Why 0.84x comes up so often

Twelve semitones is an octave, and each semitone multiplies frequency by about 1.0595. Three semitones down is 1 divided by 1.0595 cubed, which is 0.8409. So 0.84x is exactly a minor third down. Some people like that because a clean interval keeps the harmony sounding "in tune" with itself in a way a fractional shift does not.

In practice the difference between 0.84x and 0.85x is not something listeners pick up on. But if you have a musical ear and the edit at 0.85x feels slightly sour, try 0.84x.

Other clean intervals for reference: 0.89x is two semitones (a whole step), 0.79x is four (a major third), 0.75x is close to five (a fourth is 0.749x).

BPM math for matching a target tempo

If you want the edit to land at a specific tempo, for example to match a visual loop or to sit in a particular playlist, divide the target by the original:

• Original 128 BPM, target 100 BPM: 100 / 128 = 0.78x.
• Original 95 BPM, target 80 BPM: 80 / 95 = 0.84x.
• Original 160 BPM, target 135 BPM: 135 / 160 = 0.84x.

Then check the pitch consequence from the table. If a 128 BPM track needs 0.78x to hit 100 BPM, you are taking the vocal down four semitones, and you may decide that is too far and settle for 0.85x at 109 BPM instead.

Finding the original BPM: tap along with a free BPM counter app or website for twenty seconds. You do not need to be exact.

Speed by genre

The full settings per genre, including reverb and tone, are in the genre settings guide.

The ten-second decision

You do not need to agonise. This is the test:

1. Load the song and skip to the chorus.
2. Set Reverb to 40%, Space 2.8 s, Bass +5, Tone -3. Leave them.
3. Set Speed to 0.85x. Listen for five seconds.
4. Set Speed to 0.80x. Listen for five seconds.
5. Ask: did the vocal become more beautiful or less clear?
   • More beautiful: stay at 0.80x, or try 0.78x.
   • Less clear: go back to 0.85x, or try 0.88x.
   • Not sure: 0.85x.

The chorus is the test point because it is where the vocal is highest and loudest, and where the reverb tail has the most to compete with. If the chorus works, the verses will.

Signs you have gone too slow

• The kick drum has become a soft thud with no click.
• Hi-hats sound like a shuffle rather than a pattern.
• Male vocals have a gargle on sustained notes.
• You can hear the reverb from one line still ringing through the next.
• The song feels like it is waiting for something rather than moving.

Any one of these is a reason to go up 0.03x and listen again.

Signs you could go slower

• The edit sounds like the original with reverb on it.
• The vocal is still bright and forward.
• The track is a fast genre (house, drum and bass, upbeat pop) with tempo to spare.
• The arrangement is sparse, with gaps the reverb could fill.

Speed and the other controls

Each speed asks for slightly different companions. These are not rules, just the adjustments most people end up making.

Notice that reverb mix dips at 0.80x and climbs again at 0.75x. At 0.80x you are usually still protecting a vocal, so the mix comes down. At 0.75x the vocal is already texture, and the reverb is doing the work of filling a very slow arrangement.

One speed for a whole channel

If you post regularly, pick one speed and keep it. Listeners who follow slowed channels notice when the depth changes from upload to upload, and a consistent speed makes your catalogue sound like a series. The exception is a channel that explicitly offers variants, where each upload is labelled with its speed in the title.

For batches, add every track, Select All Tracks, set the speed once and export a ZIP. If one track in the batch has an unusually low vocal, deselect it, give it 0.03x more, and export it separately.

Preserve pitch and speed

Turning Preserve pitch on removes the pitch drop and leaves only the tempo change. For the slowed + reverb style that defeats the purpose, but it is useful for comparison: play the song at 0.85x with Preserve pitch on, then off, and you will hear exactly how much of the "slowed" feel is tempo and how much is pitch. On most songs it is overwhelmingly the pitch. The pitch-preserving guide covers the practical uses.

Open the free editor: upload MP3, WAV, AAC, OGG or FLAC, adjust speed, reverb, bass, tone, width and space, then export MP3 or a ZIP of many tracks. Everything runs in your browser.