Audio Equalizer & Bass Booster
Shape the sound band by band and hear every change while the music plays.
Try before you buy.
- Free preview: the first half of the result (up to 30 seconds) at the quality you chose, with a short MySmartCoPilot chime every 10 seconds.
- Locked until you unlock it: download and share.
- Unlock: Pro pass, ₹179 for 30 days or ₹79 for 1 week, a one-time payment that never renews. Unlock: Pro pass, $5.99 for 30 days or $2.99 for 1 week, a one-time payment that never renews.
Ways to unlock shows how to get the full result.
Printing this result is locked in the free preview.
Equalizer
Listen
30 seconds of the file loop while you listen; the loudest part is picked first.
Result
Locked in the free preview. Opens the ways to unlock this result.
Locked in the free preview. Batch runs unlock with a pass.
Locked in the free preview. Query results unlock with a pass.
About the Audio Equalizer & Bass Booster
An equalizer turns frequencies up or down: more bass for small speakers, less boom in a room recording, a brighter top end, a voice that cuts through. This page has a 10-band graphic EQ — one slider per octave from 31 Hz to 16 kHz, each ±12 dB — plus a low cut and a high cut (12 or 24 dB per octave), and presets to start from: Bass boost, Bass cut, Treble boost, Treble cut, Vocal clarity, Podcast voice, De-mud, Telephone and Loudness.
Listen while you change it. Thirty seconds of your file loop while you move the sliders, through the browser’s own audio filters set exactly as the file will be written, so what you hear is what you get. Switch between Original and Equalized at the same loudness to compare the tone rather than the volume; the curve shows what the settings do.
Everything happens in your browser and nothing is uploaded. The free preview on this page is the first half of the result (up to 30 seconds) with a short MySmartCoPilot chime every 10 seconds; a Pro pass, or unlocking this one result, gives the whole file as MP3, M4A, WAV or the same kind as the original, and a video keeps its picture.
How to use it
- Choose or drop a song, recording or video (MP3, M4A, WAV, FLAC, OGG, MP4, MOV, MKV, WebM…). The page measures it and picks its loudest 30 seconds to listen to.
- Press Play under Listen, then pick a preset or move the band sliders: every change is heard at once. Switch between Original and Equalized to compare, and move Listen from to hear another part.
- Tick Low cut to remove rumble below a frequency, or High cut to soften hiss and harshness above one; 24 dB per octave cuts more steeply than 12.
- Choose the Level of the result and the format under Save as, then press Apply the EQ: without a pass you get the free preview to listen to; with a Pro pass, or once this result is unlocked, Download or Share gives the whole file.
Examples
song.mp3 (320 kbps) · preset Bass boost · Keep it from clipping
song-bass-boost.mp3 at 320 kbps: +6 dB at 31 and 63 Hz and +4 dB at 125 Hz, with the whole song lowered just enough that its peaks stay under −1 dB, so the boost does not distort.
lecture.m4a · preset Vocal clarity · Same loudness as the original
lecture-vocal-clarity.m4a: rumble below 80 Hz cut, the boomy region around 250 Hz down 2.5 dB and 2–4 kHz up 2–3 dB, at the loudness the lecture had before.
scene.mp4 · preset Telephone · the same kind of file
scene-telephone.mp4 with the picture copied unchanged and the sound narrowed to about 300–3,400 Hz, the band a telephone carries.
How the filters work
Each band is a peaking filter (a biquad) centred on its frequency — 31.5, 63, 125, 250, 500, 1,000, 2,000, 4,000, 8,000 and 16,000 Hz, the standard octave bands — and one octave wide (Q ≈ 1.41). At its centre a band changes the level by exactly the decibels you set, and by half as many half an octave away; neighbouring bands overlap, so two bands side by side at +6 dB lift everything between them by about 6 dB and their own centres by about 7. The low and high cuts are Butterworth filters: 12 dB per octave is one second-order section, 24 dB per octave two.
The formulas are those of the Audio EQ Cookbook by Robert Bristow-Johnson, which the Web Audio API also uses for the browser’s BiquadFilterNode. The live preview runs on those browser filters; the file is written with the same formulas in the page’s own code at the file’s sample rate, so the result sounds like the preview.
The level of the result
- Keep it from clipping (the default): boosts can push a song’s peaks over full scale, where they distort. The page measures the equalized result first and lowers the whole of it just enough to keep its true peaks under −1 dBTP — never louder, never squashed.
- Same loudness as the original: the result is brought back to the original’s loudness (ITU-R BS.1770), so the change sounds like a change of tone, not of volume; a limiter catches any peak over −1 dBTP.
- As equalized, peaks limited: the level the EQ gives — louder where you boosted — with a true-peak limiter at −1 dBTP. Strong boosts on an already loud song can then sound squashed.
Choosing a preset
- Bass boost for small speakers, laptops and phones; Bass cut for boomy rooms and handling noise.
- Vocal clarity and Podcast voice for speech; De-mud when a recording sounds boxy or muddy (too much around 250–500 Hz).
- Treble boost for dull recordings; Treble cut for hiss and harsh, bright ones.
- Telephone for the sound of a phone call; Loudness lifts the lows and highs for listening quietly.
Every preset is a starting point: move any slider afterwards, and double-click a slider to put it back to 0 dB.
Limitations
- An EQ changes the balance of frequencies. It cannot remove a noise that shares its frequencies with the voice or the music, and it cannot add what is not in the recording: boosting 31 Hz on a phone recording mostly boosts rumble.
- Bands at or above about 45% of the sample rate are left out (a 16 kHz voice recording holds sound only up to 8 kHz), and the page says so.
- Up to 4 hours on a computer and 90 minutes on a phone; cut longer recordings into parts first (MP3 Cutter, Video Trimmer).
- MP3 and M4A results are encoded again, which costs a little quality each time; choose WAV if you will edit the result further.
- Files with several sound tracks keep only the main one, and 5.1 sound is mixed down to stereo.
Privacy
On this device; its files download once
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot. The audio engine (and, when your file needs it, the MP3, AAC or FLAC encoder) downloads from MySmartCoPilot the first time you open a file. Your files are never uploaded.
Frequently asked questions
What do I get without a pass?
Without a pass, Audio Equalizer & Bass Booster shows the first half of the result (up to 30 seconds) at the quality you chose, with a short MySmartCoPilot chime every 10 seconds. Until you unlock it, the result can’t be downloaded or shared. A Pro, Premium or Ultimate pass, a one-time payment that never renews, unlocks the full result. The pricing page lists the passes and their prices.
Is my file uploaded?
No. The file is read, equalized and written again in your browser, on your own device; nothing about it is sent anywhere.
How do I boost the bass without distortion?
Pick Bass boost (or raise the 31, 63 and 125 Hz sliders) and keep Level of the result on Keep it from clipping. The page then lowers the whole result just enough that the boosted bass never goes over −1 dB, which is what makes boosted bass crackle.
Will the file sound like the preview?
Yes. The live preview plays through the browser’s BiquadFilterNode filters, and the file is written with the same Audio EQ Cookbook formulas that the Web Audio standard defines for those filters. Only the level can differ: when both sides play at the same loudness, and by the level option you choose.
What do the numbers on the sliders mean?
Each slider is one octave, named by its centre frequency in hertz (31 Hz to 16 kHz; “k” is a thousand). It turns that octave up or down by up to 12 dB: +6 dB is about twice the amplitude, −6 dB about half.
Can I equalize the sound of a video?
Yes. Open the video and keep Save as on the same kind of file: the picture is copied unchanged into the new file and only the sound is equalized and encoded again (AAC, or Opus in WebM). Choose MP3, M4A or WAV to keep only the sound.
What does the free preview include?
Without a pass the page equalizes the first half of your file, up to 30 seconds, in the format you chose, with a short MySmartCoPilot chime every 10 seconds, and plays it here; for a video, the first half up to 10 seconds with a watermark on the picture. The Listen player works too, with the chime on the Equalized side. The whole file needs a Pro pass, or an unlock of this one result, which makes it from the file still open on the page.
Open-source components
This page can load these open-source components, each only when a task needs it:
- It uses FFmpeg under the LGPLv2.1 and the LAME MP3 encoder under the LGPL, through libav.js: licence and source code.
- It uses FFmpeg under the LGPLv2.1, through the Mediabunny add-ons: licence and source code.
- It uses the LAME MP3 encoder under the LGPL, through the Mediabunny MP3 add-on: licence and source code.
- It uses Mediabunny under the MPL 2.0: licence and source code.
You may replace them with your own builds. Their licences and the credits of every library the site uses are on the open-source credits page.