Free Online 3-Band Equalizer

Adjust three core bands: Bass (250Hz), Mid (1kHz), Treble (4kHz) from -20 to +20dB. Three ready-made presets included: Bass Boost, Clear Vocal, V-Shape Electronic.

EQ Control Panel
Select source file (higher quality is better).
0 dB
-150+15
0 dB
-150+15
0 dB
-150+15

About this online 3-band Equalizer

The Equalizer is a classic mixing tool — it boosts or cuts specific frequency ranges to shape the "color" of sound. Three common bands: Bass (below 500Hz — kicks, bass guitar), Mid (500Hz-2kHz — vocals, lead guitar), Treble (above 2kHz — cymbals, vocal sibilants).

OneAudio Equalizer chains three FFmpeg filters: bass (shelf at 250Hz), equalizer peak (1kHz, Q=1), treble (shelf at 4kHz). Each band ranges ±20dB — enough for anything from a subtle boost to a dramatic cut. Three quick presets: Bass Boost (+15 bass, 0 mid, -5 treble), Clear Vocal (0 bass, +6 mid, +3 treble), V-Shape (+10 bass, -5 mid, +10 treble — classic EDM).

  • Three standard bands: Bass 250Hz shelf, Mid 1kHz peak, Treble 4kHz shelf
  • ±20dB range — enough for any use case
  • Three one-click presets: Bass Boost, Clear Vocal, V-Shape
  • Instant reset to 0dB, no page reload
  • Server-side FFmpeg — sample rate preserved
  • 192kbps stereo MP3 output, ready to play or re-edit

EQ a track online in 3 steps

  1. 1

    Upload a high-quality source track

    Use FLAC, WAV, or 320kbps MP3 to keep compression artifacts out. 128kbps files get muddy after boosting.

  2. 2

    Pick a preset or drag each band

    Three presets cover common needs. For fine control, drag Bass / Mid / Treble from -20 to +20dB.

  3. 3

    Click Start and A/B the result

    In 10-20 seconds, download the EQ'd MP3. Listen through headphones — iterate and re-run if needed.

Real uses of the Equalizer

Boost bass for hip-hop / EDM
Push bass +10 to +15dB on small speakers so you can actually feel kick and bass line.
Brighten vocals in a dense mix
+4-6dB mid and +2-4dB treble lifts the vocal above heavy instrumental layers.
Cut bass for bedroom speakers
Small rooms get boomy with heavy bass. Drop -8dB to keep music clear without rattling the walls.
Prep background music for podcasts
Drop bass -6dB and mid -3dB so the host's voice sits on top when they start talking.

Frequently asked questions about the Equalizer

Aren't 3 bands too few compared to a 10-band EQ?
For 90% of casual use, 3 bands are enough. 10-band parametric EQ matters for mixing/mastering. For everyday listening or podcast tuning, 3-band covers it.
Why 250Hz / 1kHz / 4kHz?
These are the ITU-R reference points: 250Hz separates bass from low-mid, 1kHz is the center of vocal presence, 4kHz isolates sibilance. Most commercial EQ presets use these anchors.
Can aggressive boosts cause distortion?
Possibly. If Bass + Mid + Treble total beyond +20dB, the file can clip. Run the output through Booster safe mode to normalize to a safe -14 LUFS.
What's V-Shape?
V-Shape is a preset with boosted bass + treble and a mid cut — the curve looks like a "V". Popular in EDM, hip-hop, rock for an "open" and "full" feel.
Does EQ degrade audio quality?
Technically, each filter adds tiny processing noise. In practice, with ±20dB FFmpeg filters, the change is imperceptible to human ears.
Can I tune frequencies beyond the 3 bands?
The current version uses fixed frequencies. For parametric EQ (adjustable frequency, Q, gain), use a DAW like Reaper or a plugin like FabFilter Pro-Q.