StudioWavePro — Online Audio Editor with 48+ Studio Tools

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The Stereo Widener rebalances how much of your track lives in the center versus the sides. Under the hood it splits the stereo signal into Mid (what both channels share — typically vocals, bass, kick) and Side (what differs between them — reverb, ambience, wide-panned instruments), scales the Side component by your chosen width, and reassembles the file. At 1× nothing changes; below 1× the image narrows down to pure mono at 0; above 1× the sides bloom outward, up to 2.5×.

The slider works live during preview, so you hear the image stretch and collapse in real time. The panel’s own warning is worth repeating: past about 2× things can get "phasey" — the hollow, unstable quality of an over-widened mix — and extreme widths can misbehave when played back in mono. Wide is a seasoning, not a main course.

When to use

Open up a narrow-sounding mix so it fills headphones better.
Add space to a track that feels mono-ish despite being stereo.
Narrow an over-wide mix that falls apart or feels hollow.
Tighten the image of a recording before layering it under a centered voice.
Create contrast: narrow the verse, widen the chorus (split the file, process separately, rejoin).

How to use

Click "Open Stereo Widener" below to launch the editor.
Drop in a stereo audio file — MP3, WAV, OGG, M4A and FLAC are all supported.
Press "Play preview" and drag the width slider: 0 is mono, 1 is the original image, 1.5 (the default) is noticeably wider, 2.5 is extreme.
Listen for the phasey, hollow quality past 2× — back off if the center starts feeling empty.
Click Apply, then download as WAV or MP3.

Tips

Subtle wins: 1.2–1.5× adds air most listeners feel but can’t name; 2×+ is a special effect.
Check mono compatibility after widening — phone speakers and many Bluetooth units sum to mono, where exaggerated Side content partially cancels. Run the result through the Mono Converter as a quick test (then Undo).
Widening boosts whatever is different between channels — including channel noise and reverb. If the sides get hissy or washy, use less.
A mix can be wide and still centered: widening doesn’t move the image left or right. For that, use Stereo Balance.
Want to hear what actually lives in your Side channel before widening it? The Channel Extractor’s "Side" mode plays exactly that.

Frequently asked questions

How do I make my audio sound wider?: Open the Stereo Widener, press Play preview, and nudge the slider above 1× — 1.3 to 1.7× covers most tastes. The sides of the mix (ambience, panned instruments) get louder relative to the center. Apply and download when it feels right.
How does stereo widening actually work?: Mid/side processing: the track is decomposed into Mid (the mono-compatible center: L+R) and Side (the stereo differences: L−R). Scaling the Side up makes the image wider; scaling it down narrows it; zero Side is mono. The tool does the decompose-scale-recombine cycle per sample.
Why does my track sound hollow or "phasey" when widened a lot?: Past roughly 2×, the boosted Side content starts overpowering the Mid, and the parts of the signal that are out of phase between channels dominate — the ear reads that as hollow and unstable. It also collapses badly on mono playback. Use extreme widths as a deliberate effect, not a default.
Can I use this to convert mono to stereo?: No — a mono file has no Side component to scale, so there is nothing to widen (the tool will tell you). True mono-to-stereo enhancement requires creating artificial differences, e.g. layering a short Echo or different EQ per channel in a DAW.
What happens at width 0?: The Side component is removed entirely and both channels carry the identical Mid signal — functionally mono, but still saved as a two-channel file. If you want an actual one-channel file, the Mono Converter does that and halves the file size.
Will widening cause problems on phone speakers?: It can: single-speaker devices sum left and right, and anything you boosted in the Side channel partially cancels in that sum — the track can sound thinner there than the original. Stay moderate (≤1.5×) for material destined for phones, or test the mono sum before publishing.

StudioWavePro is a complete audio editor with 48+ studio-grade tools in one workspace. Trim, master, EQ, time-stretch, denoise, remove vocals, detect BPM and musical key, generate metronomes, and more. Editing tools

Audio Trimmer — crop a track to a selected region

Mute Section — silence a selected region

Reverse Audio — play the track backwards

Fade In/Out — ramp volume at start or end

Silence Trimmer — strip leading and trailing silence

Silence Gap Inserter — insert silence at a chosen position

Audio Looper — repeat a section N times

Audio Splitter — cut a track into multiple parts

Audio Merger — join multiple files end-to-end

Silence Splitter — auto-split at silent gaps

Crossfade Joiner — join clips with overlapping fades

Time and pitch

Speed Changer — speed up or slow down (with optional pitch preservation)

Pitch Shift — change pitch without changing tempo

Tempo Detector — estimate the BPM of a music track

Key Detector — estimate the musical key

Metronome Generator — create a click track at any BPM

Effects

Volume — make a track louder or quieter

Bass Boost — lift the low end

Treble Boost — lift the high end

Low Pass Filter — cut off high frequencies

High Pass Filter — cut off low frequencies (remove rumble)

Equalizer (3-band) — low / mid / high tonal shaping

Equalizer (10-band) — fine-grained tonal control

Echo — add repeating echoes / delay

Distortion — overdrive, fuzz, and lo-fi grit

Stereo Balance — shift the L/R center of a stereo mix

Stereo Widener — make stereo narrower or wider

Vocal Remover — karaoke (center-channel removal)

Hum Remover — strip 50/60 Hz mains hum

Mastering and analysis

Normalize — maximize volume without clipping

Compressor — even out loud and quiet parts

Loudness Meter — measure peak, RMS, and LUFS

Mono Converter — collapse stereo to mono

Channel Extractor — pull L, R, Mid, or Side

Sample Rate Converter — resample to 44.1, 48, or 96 kHz

Polarity Inverter — flip waveform for phase alignment

DC Offset Remover — center waveform around zero

Audio Visualizer — render an animated video from audio

StudioWavePro supports MP3, WAV, OGG, M4A, and FLAC files. Exports include WAV and MP3. This app requires JavaScript to run. Please enable JavaScript in your browser.