# Parametric Equalizer

Free parametric equalizer in your browser — set the exact frequency, gain and Q of three bands, then save as MP3, WAV, OGG, FLAC or M4A. Nothing uploaded.

## Run it

- **CLI:** `gizza tool parametric-eq 'url=https://example.com/input' 'band1_freq=100' 'band1_gain=0' 'band1_q=1' 'band2_freq=1000' 'band2_gain=0' 'band2_q=1' 'band3_freq=5000' 'band3_gain=0' 'band3_q=1' 'format=mp3'`
- **Web:** https://gizza.ai/tools/parametric-eq/
- **Agents:** machine-readable descriptor (parameters JSON Schema) at https://gizza.ai/tools/parametric-eq/tool.json

## Inputs

- `audio` — Audio _(file; accept: audio/*)_
- `band1_freq` — Band 1 frequency (Hz) _(field)_
- `band1_gain` — Band 1 gain (dB) _(field)_
- `band1_q` — Band 1 Q _(field)_
- `band2_freq` — Band 2 frequency (Hz) _(field)_
- `band2_gain` — Band 2 gain (dB) _(field)_
- `band2_q` — Band 2 Q _(field)_
- `band3_freq` — Band 3 frequency (Hz) _(field)_
- `band3_gain` — Band 3 gain (dB) _(field)_
- `band3_q` — Band 3 Q _(field)_
- `format` — Output format _(field)_

## Output

- Equalized audio (audio)

## Query parameters

Open the tool pre-filled and auto-run via URL:

- `band1_freq` — Band 1 frequency (Hz)
- `band1_gain` — Band 1 gain (dB)
- `band1_q` — Band 1 Q
- `band2_freq` — Band 2 frequency (Hz)
- `band2_gain` — Band 2 gain (dB)
- `band2_q` — Band 2 Q
- `band3_freq` — Band 3 frequency (Hz)
- `band3_gain` — Band 3 gain (dB)
- `band3_q` — Band 3 Q
- `format` — Output format
- `url` — fetch the input file from a public URL (CORS-permitting)

Example: `https://gizza.ai/tools/parametric-eq/?url=https://example.com/input&band1_freq=100&band1_gain=0&band1_q=1&band2_freq=1000&band2_gain=0&band2_q=1&band3_freq=5000&band3_gain=0&band3_q=1&format=mp3`

---

## About this tool

Parametric EQ lets you boost or cut exact frequency ranges instead of using fixed bass/mid/treble tone controls. Each of the three bands has:

- **Frequency** — the centre of the band in Hz, from 20 to 20000.
- **Gain** — how much to boost or cut, from -20 dB to +20 dB. A gain of `0` turns that band off.
- **Q** — bandwidth. Low Q values are wide and gentle; high Q values are narrow and surgical.

For example, set band 2 to frequency `3000`, gain `4`, Q `1.5` to add vocal presence. To reduce mud, set band 1 around `250`, gain `-5`, Q `1.2`. To add air, set band 3 around `10000`, gain `4`, Q `0.7`.

The output is re-encoded to MP3 by default, or WAV, OGG, FLAC, or M4A if you choose another format. Album-art/video streams are dropped so the result is a clean audio file.

### Limits

At least one band must have a non-zero gain; otherwise there is nothing to process. The tool applies three peaking EQ bands, not shelves, high-pass filters, or a live spectrum analyzer. Very large source files are capped by the standard audio upload limit, and boosted bands can cause clipping if the original audio already peaks near full scale — cut other bands or normalize first when in doubt.

## FAQ

<details>
<summary>How is this different from the regular audio equalizer?</summary>

The regular audio equalizer has fixed bass, mid, and treble frequencies. This parametric EQ lets you choose the exact frequency and Q of every band, so it can target a narrow resonance, a specific vocal range, or a custom tonal shape.

</details>

<details>
<summary>What Q value should I use?</summary>

Use a low Q such as `0.7` for broad musical tone shaping, around `1` to `2` for normal corrective moves, and higher values such as `5` or more for narrow notches. Extremely narrow high-Q boosts can sound harsh, so use them carefully.

</details>

<details>
<summary>Why does a 0 dB band do nothing?</summary>

A gain of 0 dB means no boost and no cut, so that band is omitted from the ffmpeg filter chain. This keeps the output cleaner and avoids unnecessary filters.

</details>

<details>
<summary>Can boosting a band clip the audio?</summary>

Yes. Any positive gain raises part of the signal and may push peaks over full scale. If you hear distortion, reduce the boost, cut surrounding bands instead, or run a normalization/limiting tool after EQ.

</details>

<details>
<summary>Which output format should I choose?</summary>

Use MP3 for compact sharing, WAV or FLAC for lossless workflows, OGG for open web audio, and M4A when AAC compatibility is important. Re-encoding lossy input to another lossy format can reduce quality, so keep lossless sources when possible.

</details>

## Related tools

- [Equalize an Audio File](https://gizza.ai/tools/audio-eq/): Equalize any audio file right in your browser — boost or cut bass, mid and treble in dB, then save as MP3, WAV and more. Nothing is uploaded, free.
- [Change Audio Volume](https://gizza.ai/tools/audio-volume-adjust/): Boost or cut any audio file's volume right in your browser — by decibels or a factor, with a clipping-safe peak limiter. Nothing is uploaded, free.
- [Bleep or Mute Regions of an Audio File](https://gizza.ai/tools/audio-bleep-censor/): Censor an audio file in your browser — bleep, mute, or duck the exact time regions you pick. Set a tone frequency and output format. Nothing is uploaded, free.
- [Compress an Audio File](https://gizza.ai/tools/audio-compress/): Shrink MP3, WAV, M4A or any audio file right in your browser — pick a target bitrate (96 kbps default) and format. Nothing is uploaded, free.
- [Convert an Audio File](https://gizza.ai/tools/audio-convert/): Convert any audio file to MP3, WAV, OGG, FLAC or M4A right in your browser — pick a bitrate for lossy formats. Runs locally, nothing is uploaded, free.