A five-band equalizer for the music you own

REWIND has a five-band equalizer with bands at 60 Hz, 250 Hz, 1 kHz, 3.5 kHz and 12 kHz, plus five presets: Flat, Warm, Bass, Vocal and Air. It works on every file in your library, in real time, offline, and it is free to use.

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What are the five bands?

Each band is a slider that boosts or cuts one region of the spectrum. Five is deliberately few. You get quick, audible moves instead of a wall of tiny sliders.

Band	What it controls	Typical use
60 Hz	Sub-bass and kick weight	Add thump, or trim boom on small earbuds
250 Hz	Low mids, warmth, mud	Cut a little if vocals sound clogged
1 kHz	Midrange body	Pushes instruments forward
3.5 kHz	Presence and bite	Adds clarity to vocals, can get harsh
12 kHz	Air and shimmer	Opens up dull, old recordings

What do the presets do?

Presets are starting points that you can move away from afterwards. Their names tell you the intent.

Flat: all bands at zero. Use it to hear the file untouched.
Warm: a rounder, softer balance.
Bass: more weight in the lowest bands.
Vocal: voices sit further forward.
Air: a brighter top for dull masters and lo-fi rips.

How do I set it up for headphones?

Start from Flat and change one band at a time while a familiar song plays. Boost less than you think you need; small moves sound natural, big ones add noise and can cause distortion on loud tracks.

If you are chasing a specific result, best EQ settings for headphones on iPhone walks through common problems like boomy bass and harsh vocals. A rule that holds up: cut before you boost. Taking down a muddy 250 Hz often helps more than lifting everything else.

Open the sound screen and find the equalizer.
Pick Flat, then play a song you know well.
Move one band at a time and listen for ten seconds.
Leave the sliders where they sound right; the setting keeps applying to the next track.

Equalizer and analog sound together

The equalizer shapes frequencies. Analog sound adds tape saturation, wobble, hiss and vinyl crackle. They are two separate stages and you can run both. A common pairing is the Warm preset with a little saturation, which gives a convincing cassette tone.

Need more level on a quiet recording? REWIND PRO adds a volume boost of up to +9 dB with a limiter, which keeps peaks from clipping.

What it is not

It is a taste tool, not a measurement tool. There are five fixed bands and no parametric controls. If you want five clear levers on a retro player, that is the point; if you want surgical correction, a dedicated audio app suits you better.

Five bands, five presets, no account.

Is the equalizer free?

Yes, the equalizer is part of the free tier, together with analog sound, import and lock-screen controls. Slowed + Reverb, Sped up, reverb depth, 8D audio, the volume boost and the larger machine catalog need REWIND PRO.

A quick example: rescuing a dull old rip

Say you ripped an old tape to a file and it sounds muffled. Start from Flat, lift 12 kHz a little for air, then lift 3.5 kHz by a smaller amount so voices regain edge. If hiss gets loud, back the top band down again. A few small moves usually beat large ones.