Audio synchronization is one of the most important parts of creating a polished Friday Night Funkin’ mod. When the instrumental starts before the vocals, character singing animations feel disconnected from the music, or notes appear out of time, even a well-designed song can become frustrating to play. Fortunately, most synchronization issues can be fixed by checking the audio files, correcting track alignment, and verifying chart timing.
In FNF Psych Engine, custom songs commonly use two separate audio files: Inst.ogg for the instrumental and Voices.ogg for the vocals. These tracks must share the correct starting point, duration, and musical timing to produce a consistent gameplay experience. This guide explains how to prepare, synchronize, export, and test both files while avoiding common mistakes that can cause audio desynchronization.
Understanding Inst and Voices Files in FNF Psych Engine
Before changing any settings, it helps to understand how Psych Engine uses separate audio tracks. Each file has a specific purpose, and incorrect timing in either track can affect how the song sounds during gameplay.
What Does Inst.ogg Do?
The Inst.ogg file contains the instrumental version of your song. Depending on the arrangement, it may include drums, bass, synthesizers, guitars, piano, and other background elements. It provides the musical foundation that players hear while following the note chart.
When creating a custom song, your instrumental should have a clear starting point and consistent timing. Unnecessary silence at the beginning, an incorrectly trimmed ending, or an unsuitable export can make the song behave differently than expected. Keeping a clean, correctly aligned instrumental makes the remaining synchronization process much easier.
Why Must Voices.ogg Match the Instrumental?
The Voices.ogg file contains the vocal stems used during gameplay. These may include the player character’s vocals, the opponent’s singing, or a combined vocal track, depending on how the song was prepared. Psych Engine uses these vocals alongside the instrumental to make character singing feel connected to the music.
Both tracks need to use the same timeline. If the instrumental begins at zero seconds but the vocal file starts several milliseconds later, the vocals may sound delayed. Similarly, if one file has extra silence or a different duration, the tracks can become misaligned even when they sound correct in a separate audio player.
Prepare Your Audio Files Before Syncing
Preparation prevents unnecessary editing and helps you identify whether the problem comes from the audio itself, the chart, or the engine configuration. Start by locating the correct song folder and making a backup before replacing any original files.
Locate the Correct Song Assets
Open your Psych Engine installation or mod directory and locate the folder containing your custom song assets. Depending on the engine version and how the mod is organized, song files are commonly stored in a path resembling mods/data/song-name/ for chart data and mods/songs/song-name/ for audio assets. Some builds or custom projects use different folder structures, so confirm the layout used by your specific installation.
Inside the relevant audio folder, look for Inst.ogg and Voices.ogg. Check that the names match the expected filenames exactly, including capitalization where relevant. Keep your original files somewhere safe, because a backup allows you to restore a working version if the new exports cause playback errors.
Check Audio Format and Quality
Use an audio editor that supports multitrack editing, such as Audacity or another digital audio workstation. Import both files into the same project and inspect their waveforms. This makes it easier to compare the opening transients, vocal entrances, musical phrases, and endings.
For typical Psych Engine song assets, OGG Vorbis is a commonly used format. Export both tracks using compatible settings and listen to the resulting files before putting them into the mod. Avoid repeatedly converting compressed audio, as multiple lossy conversions can reduce sound quality. If you still have the original WAV or other lossless source files, use those as your starting point whenever possible.
How to Sync Inst and Voices in FNF Psych Engine
The most reliable approach is to align both tracks in one editing session before exporting them. This lets you compare their timing visually and by listening rather than relying on guesswork or changing random engine settings.
Align Both Tracks in an Audio Editor
Import the instrumental and vocal files into separate tracks within the same audio project. Make sure both tracks share the same timeline origin. If the vocal file contains silence before the first actual vocal sound, determine whether that silence is intentional or whether it was introduced accidentally during export.
Listen to recognizable moments, such as the first vocal syllable, a strong drum hit, or the beginning of a chorus. Zoom in on the waveforms to check whether the corresponding events occur at the intended times. If the vocal track starts late, move it earlier by the measured amount; if it starts too early, move it forward. Avoid shifting the entire track based on one uncertain sound, because vocal delivery may intentionally lead or lag the beat.
Keep Both Tracks on a Shared Timeline
A common mistake is trimming the beginning of each file independently. Removing a quiet opening from the vocals while leaving the instrumental untouched changes their relative timing. The same problem occurs when one file is exported with a different amount of leading silence.
Instead, preserve a consistent timeline when exporting both files. If the instrumental starts at zero and the vocals are supposed to enter later, the vocal file should still retain the appropriate silence before that entrance. This ensures the vocal sound occurs at the intended point without requiring the engine to guess how the tracks should line up.
Export and Replace the Correct Files
Once the tracks sound synchronized in your editor, export them separately using the filenames expected by your song setup: Inst.ogg and Voices.ogg. Confirm that the files were exported successfully and that neither contains unexpected silence, clipping, or an abrupt ending.
Replace the corresponding files in your mod’s song folder, keeping your backup intact. Avoid placing the new files in an unrelated directory or leaving duplicate versions with confusing names. If the engine continues playing the old audio, close and restart the game before testing again. This helps ensure that you are evaluating the files you actually replaced.
Check BPM, Chart Timing, and Song Offset
Correctly aligned audio does not automatically mean that the chart will be synchronized. Psych Engine also relies on chart timing information, including beats per minute (BPM), note positions, and any applicable timing changes. If the BPM is incorrect, notes can gradually drift away from the beat even when the instrumental and vocal tracks are perfectly aligned.
Open the song in the chart editor and confirm that the BPM matches the music. For songs with tempo changes, check that the relevant sections are configured correctly. Song offset settings can help address a consistent timing difference between the music and chart, but they should not be used to compensate for vocals that are misaligned relative to the instrumental. Fix the underlying problem in the appropriate place.
Fix Common FNF Psych Engine Audio Sync Problems
Audio problems can have different causes, even when they seem identical during gameplay. The key is to identify whether the issue affects the entire song, only the vocals, or the timing of the notes.
Vocals Start Too Early or Too Late
If the vocals sound consistently early or late throughout the song, inspect the opening sections of Inst.ogg and Voices.ogg. Check for extra leading silence, accidental trimming, or a small time shift introduced during editing. Compare a few recognizable musical events before adjusting the track.
Correct the timing in your audio editor, then export and test the files again. Do not automatically change the chart offset to fix a vocal-only problem, because doing so may make the notes less accurate while leaving the relationship between the instrumental and vocals unchanged.
Audio Drifts Out of Sync During Gameplay
When the vocals begin correctly but gradually become misaligned, investigate the duration and timing of both files. Different edits, incorrect time stretching, or exports with altered playback speed can cause the tracks to diverge over time.
Compare the same musical event near the beginning, middle, and end of the song. If the difference increases progressively, check whether either file has been stretched, resampled incorrectly, or exported from a project with inconsistent tempo settings. Rebuild both exports from the same source timeline rather than making a series of small adjustments at different points.
Notes Do Not Match the Music
If both audio tracks sound synchronized but the notes feel early or late, the chart may be the source of the problem. Check the song’s BPM, note placement, section timing, and offset configuration. A chart created for a different version of the song may not match a newly edited instrumental.
Avoid shifting every note immediately. First, compare the chart against strong beats at multiple points in the song. A constant difference suggests an offset issue, while an increasing difference may indicate an incorrect BPM or a tempo change that was not configured properly.
Missing Vocals, Distortion, or Playback Errors
If the instrumental plays but the vocals are missing, verify the filename, directory, file integrity, and export format. Ensure that Voices.ogg is not accidentally empty and that it contains audible vocal content. Also confirm that your chart or song configuration is not set up in a way that intentionally omits the vocal track.
Distortion can result from clipping in the source audio, excessive gain, or poor-quality conversions. Return to the original project, check the levels, and export a clean version. If the game crashes or fails to load the audio, test the exported file independently and confirm that it is a valid OGG file rather than a renamed file in another format.
Fix Incorrect Vocal Stems or Character Singing
Sometimes the problem is not timing but the content of the vocal track. A custom song may use separate vocal stems for the player and opponent, while the supplied Voices.ogg combines them differently or omits one character’s part. This can make singing animations appear disconnected from the audible vocals.
Review how your song’s stems were prepared and how your specific Psych Engine build handles vocals. If the project requires combined vocals, make sure the intended vocal content is included. If separate stems are supported by your setup, follow its expected naming and configuration instead of assuming that every build handles them identically.
Test Audio Synchronization in Gameplay
Testing inside the actual game is essential because an audio editor cannot reproduce every aspect of Psych Engine’s playback and chart timing. After replacing the files, launch the mod and play through the opening, a middle section, and the ending.
Pay attention to vocal entrances, drum hits, character animations, note judgments, and the transition between song sections. If the opening sounds correct but later sections do not, compare the relevant timestamps in your editor and check the chart’s BPM and timing changes. Testing multiple sections helps you distinguish a simple starting offset from a problem that accumulates over time.
For the most reliable result, make one change at a time and test again. If you move the vocals, change the BPM, and adjust the song offset simultaneously, you may fix one symptom while creating another. A controlled process makes it easier to identify the actual cause and preserve accurate timing throughout the song.
Best Practices for Custom Song Audio in Psych Engine
Maintain a clean source project containing the original instrumental, vocal stems, and final exports. Keep both tracks tied to the same timeline and avoid trimming or stretching them independently unless the arrangement specifically requires it. Consistent file naming and organized song folders also reduce the chance of loading the wrong audio assets.
Before releasing a mod, test the song from beginning to end and verify that the audio, chart, and character animations remain synchronized. Check the exact engine version you are using, especially if you are working with a fork or a heavily customized build. Different versions may handle song assets and configuration differently, so use the conventions supported by your project rather than assuming every Psych Engine installation behaves identically.
Advanced Audio Timing Checks for FNF Psych Engine
Understand the Difference Between Audio Offset and Track Alignment
Audio offset and track alignment solve different problems. Track alignment determines the timing relationship between Inst.ogg and Voices.ogg, while chart offset concerns the relationship between the song’s audio and the note timing. Confusing these settings is a common reason creators struggle to fix custom song synchronization.
For example, if the vocals are consistently late compared with the drums, adjust the vocal track in the audio editor. If the vocals and instrumental sound correct together but note judgments consistently occur too early, investigate chart timing and offset instead. Separating these two problems helps you avoid unnecessary edits and maintain a reliable gameplay experience.
Check for Sample Rate and Export Differences
Sample rate describes how many audio samples are recorded per second. Different source settings are not automatically a problem, but inconsistent conversions or incorrect time-stretching can change playback behavior. When preparing custom music, export both tracks from the same project and use consistent settings wherever practical.
Listen to the final OGG files rather than relying only on the original project. A successful export should preserve the intended timing, sound quality, and duration. If a track plays correctly in your editor but behaves differently in the game, test the exported files independently and confirm that they are valid, complete, and using the expected format.
Avoid Random Timing Adjustments
Repeatedly moving a track by an arbitrary amount can make synchronization harder to troubleshoot. Instead, identify a clear reference point, measure the timing difference, and make one controlled adjustment. Then compare another musical event later in the song to confirm that the correction remains accurate.
If the timing difference stays constant, a simple track shift may be sufficient. If it increases throughout the song, investigate playback speed, time stretching, sample-rate conversion, or tempo-related issues. If only the notes are inaccurate, review the chart rather than changing the audio files.
A Practical Workflow for Reliable Song Synchronization
A dependable workflow begins with a backup and a clean source project. Import the instrumental and vocal tracks together, inspect their waveforms, and align recognizable musical events. Preserve intentional silence so that vocals enter at the correct musical moment, then export both files with the correct names and compatible settings.
Next, place the files in the appropriate song directory and launch the mod. Test several sections, compare the note chart against the beat, and change only the setting associated with the problem. If the tracks are synchronized but the chart is not, verify the BPM and offset. If the vocals are missing or distorted, inspect the exported file and folder configuration before making timing changes.
This method is more reliable than trial and error because every adjustment has a clear purpose. It also makes future updates easier: when you revise a song, you can return to the source project, reproduce the exports, and confirm that the new files maintain the original timing.
Conclusion
Synchronizing instrumental and vocal tracks is essential for smooth gameplay and professional-quality custom songs. In FNF Psych Engine, the best approach is to align Inst.ogg and Voices.ogg on a shared timeline, export compatible files, verify the BPM and chart timing, and test the result in-game. Keep track alignment separate from song offset adjustments, and investigate gradual audio drift instead of randomly shifting tracks. With a consistent workflow, you can fix most common synchronization problems and create a more polished Friday Night Funkin’ mod.