Audio Live Help

AUDIO SURROUND STUDIO HELP

Convert stereo to 5.1 surround sound in your web browser

Last updated: October 24, 2026

Surround Studio turns a two-channel song or video soundtrack into six-channel 5.1 audio. You can adjust the sound live while it plays, then export a WAV, FLAC or AC3 file for your home theater. Your audio is never uploaded: all processing happens in your browser.

1. QUICK START

1) Load a file. Drop an audio or video file on the page, or tap the drop zone. Most formats your browser can play work, including MP3, WAV, FLAC, M4A, OGG and MP4.

2) Press "Play live". Move any slider while it plays and the change is heard instantly.

3) Choose your settings. See section 3 for good starting values.

4) Press "Render for export". This builds the file with your current settings.

5) Choose a format and press "Export". See section 5.

Requirements: a recent desktop browser such as Chrome or Edge. A 3-minute song makes a WAV of about 100 MB, because it holds six channels.

Example -

Original Sound Track ----> After the changes Sound Track

2. CONTROLS

Live player ..... Play, pause, stop and seek. Speaker circles glow with each channel's level.

Center .......... Level of the center speaker (dialogue, lead vocals). 0-100%.

Surround ........ Level of the rear speakers, built from the difference between left and right. 0-100%.

Subwoofer (LFE) . Level of the bass-only channel. 0-100%.

Sub crossover ... Highest frequency sent to the subwoofer. 40-200 Hz.

Surround delay .. Delays the rear speakers so the sound feels wider. 0-40 ms.

dB trim ......... Fine level for each of the six channels, -24 to +12 dB. Presets: Reset, Rear-heavy.

Graphic EQ ...... 10 bands from 31 Hz to 16 kHz, +/-12 dB. Presets: Flat, Bass boost, Cinema, Voice, Loudness.

3. STARTING SETTINGS FOR MUSIC

Adjust by ear and change one control at a time.

Center / Surround / Subwoofer ... 40% / 55% / 80%

Sub crossover / Surround delay .. 80 Hz / 15 ms

dB trim ......................... Front 0, Center 0, Sub 0, Surround -2

Equalizer ....................... 31 and 62 Hz +2, 125 Hz +1, 250 Hz to 2 kHz 0, 4 kHz +1, 8 kHz +2, 16 kHz +1

4. EFFECTS RACK

Open the Effects rack, pick a tab and switch on any effect. Effects run before the 5.1 split, so they shape all six channels. Start with low mix and drive values. The Limiter protects the final output from clipping.

Space ........... Reverb (Room, Hall, Plate, Spring, Custom impulse response), Delay (Slapback, Ping-Pong, Tape)

Modulation ...... Chorus, Flanger, Phaser, Tremolo, Vibrato, Auto-pan

Dynamics ........ Compressor, Limiter, Noise gate / Expander, De-esser

Tone ............ Filter (high-pass, low-pass, band-pass), Parametric EQ

Grit ............ Saturation, Overdrive, Distortion, Fuzz, Bitcrusher

Vocal & Pitch ... Vocal remover (karaoke), Pitch shift / Harmonizer, Time stretch, Vocoder

5. EXPORT AND PLAYBACK

WAV 16-bit ........ Best for editing, VLC, Kodi and PC players. Largest file. Six channels in standard 5.1 order.

FLAC .............. Lossless storage. About half the size of WAV. Long tracks take time to encode.

AC3 (Dolby Digital) Best for home theater receivers. Browsers cannot encode AC3, so the app downloads the WAV and shows an ffmpeg command:

    ffmpeg -i surround-5.1.wav -c:a ac3 -b:a 640k surround-5.1.ac3

Playing it on a home theater:

- Use a USB drive or media player. Many receivers do not play 6-channel WAV or FLAC, but they decode AC3 reliably.

- On a smart TV, set the audio output to Bitstream, Passthrough or Auto (not PCM), or 5.1 may be reduced to stereo.

- On the receiver, choose Direct, Multi-channel or Auto. Turn off extra surround or cinema processing so the sound is not processed twice.

- To hear 5.1 live from a computer, set the computer's HDMI audio output to 5.1 in its sound settings.

6. THE SIX CHANNELS

FL / FR ... Front left and right. The original left and right.

C ......... Center, under or above the screen. Left plus right, with deep bass removed.

LFE ....... Subwoofer. Left plus right, low-passed at your crossover.

SL / SR ... Beside or behind you. Left minus right, delayed, softened above 7 kHz, opposite polarity on each side.

7. SPEAKER SAFETY

- Set the receiver volume low before the first play, then raise it slowly.

- Avoid large LFE boosts. Keep the crossover at 80-120 Hz so the sub is not overdriven.

- Stop right away if you hear crackling, buzzing or the sub "banging".

- Change trims in steps of about 3 dB and test after each change.

8. LIMITS

- Artificial surround. It cannot match a track originally mixed in 5.1. A mono file leaves the surround channels silent.

- Vocal remover. It only removes center-panned vocals. For clean results on any song, use AI stem-separation software.

- No Auto-Tune. Automatic pitch correction is not included.

- Pitch and time tools. Large shifts can sound slightly watery. The gate, bitcrusher and pitch tools add about 40 ms of delay.

- Preview. Without a 5.1 audio output you hear a stereo downmix.

9. TROUBLESHOOTING

"Could not decode this file" ..... Convert the file to MP3 or WAV and try again.

Output too quiet or bass weak .... Raise the sub and center levels a little. Avoid heavy front cuts; the Limiter controls peaks but does not raise the volume.

Sound is harsh or distorted ...... Lower the LFE trim, the equalizer boosts or the effect drive values.

Rear speakers are silent ......... Check the source is stereo, raise Surround, and set your receiver to Direct or Multi-channel.

Only stereo plays on the TV ...... Set the TV audio output to Bitstream, Passthrough or Auto, and use AC3 for the file.

FLAC export is slow .............. Wait for the percentage to finish, or export WAV and convert it with ffmpeg.

10. FREQUENTLY ASKED QUESTIONS

Q: Is my audio uploaded to a server?

A: No. All processing happens in your browser, so your audio never leaves your device.

Q: Is this real 5.1 surround sound?

A: It is an artificial (matrix) upmix. It creates six channels from two, but it cannot match a track that was originally mixed in 5.1.

Q: Which export format works best with a Sony home theater?

A: AC3 at 640 kbps is the most widely accepted. Many receivers do not play 6-channel WAV or FLAC from a TV or USB port.

Q: Can I remove vocals from a song?

A: Partly. The vocal remover cancels sound panned to the center and keeps the bass. Backing vocals, reverb and stereo-wide vocals usually stay audible.

Q: Why do I only hear stereo in the preview?

A: Browsers play six channels only if the computer's audio output is set to 5.1. Otherwise you hear a stereo downmix, although the speaker meters still show all six channels.

Q: Does the app include Auto-Tune?

A: No. Pitch shift, harmonizer, time stretch and vocoder are included, but automatic pitch correction is not.

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