Guide
Video audio distorted after uploading? Keep your peaks under -1 dB
Updated
Audio usually distorts after uploading because the loudest moments sit too close to the maximum. Each conversion to MP4, first on your computer and then in the app, can push them over.
In short
- Audio usually distorts after uploading because the loudest moments sit too close to the maximum, and converting to MP4 can push them over.
- A recording that already crackled, because the mic was too close or the gain too high, cannot be fixed by an export setting.
- Phone speakers are small and distort first, especially on loud moments and deep bass.
- A limiter set to -2 dB keeps the exported file under the safe -1 dBTP mark.
- In a test of 12 finished ads by Cutroom, 5 had peaks above -1 dBTP after export when no limiter was used.
- Finished ads with peaks above -1 dBTP after export, with no limiter
- 5 of 12
- How far the MP4 conversion pushed one sudden loud sound
- 2 dB
- The limiter setting that kept every file under -1 dBTP
- -2 dB
Why does audio distort after uploading?
Audio distorts when a sound goes over the maximum a file can hold. That happens in the recording, in the export, or on a small speaker.
- The recording itself crackled, because the mic was too close, the gain was too high, or wind hit the mic.
- The peaks sat too close to the maximum. An MP4 stores sound as AAC, which can push peaks higher than your editor showed.
- TikTok, Instagram and YouTube convert every upload again, and each conversion can push a peak that sits close to the maximum over it.
- Phone speakers are small and distort first, especially on loud moments and deep bass. Laptop speakers and headphones hide more of it.
The usual causes and what to do
| Cause | How to tell | What to do |
|---|---|---|
| The recording crackled | It crackles in your editor too | Record it again, or try a declip tool |
| Peaks too close to the maximum | Clean in the editor, crackles after export | Add a limiter set to -2 dB |
| Too much bass for a phone | It crackles mostly when the music hits | Turn the bass of the music down |
Cause: The recording crackled
- How to tell
- It crackles in your editor too
- What to do
- Record it again, or try a declip tool
Cause: Peaks too close to the maximum
- How to tell
- Clean in the editor, crackles after export
- What to do
- Add a limiter set to -2 dB
Cause: Too much bass for a phone
- How to tell
- It crackles mostly when the music hits
- What to do
- Turn the bass of the music down
How much can an MP4 export push the peaks up?
Cutroom, a video ad editor, measured 12 of its own finished ads after export. They aimed for peaks under -1 dBTP, with no limiter.
- 5 of the 12 had peaks above the safe -1 dBTP mark after export. The worst reached -0.27 dBTP.
- The MP4 conversion usually added up to about 0.7 dB. On one sudden loud sound, it added about 2 dB.
- None of the 12 went over 0 dBTP, but peaks that close to the maximum can crackle after the app converts the video again.
The highest peak after export, measured by Cutroom
Closer to 0 means a higher peak. Only the -2 dB limiter kept every file under -1 dBTP.
| File | Highest peak after export |
|---|---|
| The limit to stay under | -1 dBTP |
| Worst file, no limiter | -0.27 dBTP |
| Limiter set at -1 dBTP | -0.31 dBTP |
| Limiter set at -2 dBTP | -1.3 to -1.5 dBTP |
File: The limit to stay under
- Highest peak after export
- -1 dBTP
File: Worst file, no limiter
- Highest peak after export
- -0.27 dBTP
File: Limiter set at -1 dBTP
- Highest peak after export
- -0.31 dBTP
File: Limiter set at -2 dBTP
- Highest peak after export
- -1.3 to -1.5 dBTP
This is the whole editor
Highlight a phrase and a clip lands on those exact words. No timeline, no keyframes, no layers.
How to set your limiter
A limiter stops the loudest moments at a level you choose. Set it to -2 dB, so the exported file lands under -1 dBTP.
- In Premiere Pro, the limiter is the Hard Limiter effect. Set its maximum amplitude to -2 dB.
- In DaVinci Resolve, the limiter is in the Dynamics panel on the Fairlight page. Set it to -2 dB.
- In Audacity, which is free, use the Limiter effect and set it to -2 dB.
- CapCut and iMovie have no limiter you can set, so lower the volume of the loudest clips instead.
- Turn off auto-level if your limiter has it. Some limiters call it auto-gain, and it pushes the sound straight back up to the maximum.
Should the limiter react fast or slow?
A little slower is safer. The attack setting is how fast the limiter turns a loud moment down, and 15 ms worked better than 5 ms.
- In Cutroom's tests with the ffmpeg limiter, the 5 ms setting pushed one peak about 2 dB over after export. The 15 ms setting stayed 1 dB under.
- Set the release, which is how fast the limiter lets go, to about 150 ms for the same reason.
- If your limiter has a latency compensation switch, turn it on so the sound stays in sync with the picture. Most editors do this for you.
Two attack settings on the same file
Measured by Cutroom with the ffmpeg limiter. Other limiters can behave differently.
How the level changes
- 5 ms attack
- In sudden jumps
- 15 ms attack
- Smoothly
What the MP4 conversion does
- 5 ms attack
- Turns a jump into a spike
- 15 ms attack
- Follows it cleanly
Peak after export
- 5 ms attack
- About 2 dB over the limit
- 15 ms attack
- 1 dB under the limit
| 5 ms attack | 15 ms attack | |
|---|---|---|
| How the level changes | In sudden jumps | Smoothly |
| What the MP4 conversion does | Turns a jump into a spike | Follows it cleanly |
| Peak after export | About 2 dB over the limit | 1 dB under the limit |
How to check a video you already posted
Measure the file people actually hear, not the one on your computer.
- Use a meter that shows true peak, written dBTP. The free Youlean Loudness Meter shows it as TP, and so does Premiere Pro's Loudness Meter.
- Uploading the same file again changes nothing. Set the limiter, export again, then upload the new file.
- If it crackles in your editor too, the recording itself crackled. Record it again, or try the free Clip Fix effect in Audacity.
Check a posted video in four steps
Download it
From the app, not from your drive
Measure the true peak
With a meter that shows dBTP
Over -1 dBTP?
Your peaks are too close to the maximum, and the next conversion can make them crackle
Listen on a phone
At full volume, in a quiet room
Where Cutroom fits
Cutroom is a video editor that turns one clip of you talking into a finished vertical ad. Cutroom uses these limiter settings on its exports, and you cannot change them.
The limiter on a Cutroom export
| Setting | Value |
|---|---|
| Limiter | -2 dBTP |
| Attack | 15 ms |
| Release | 150 ms |
| Auto-level | Off |
| Loudness | -14 LUFS |
| Can you change it? | No |
Setting: Limiter
- Value
- -2 dBTP
Setting: Attack
- Value
- 15 ms
Setting: Release
- Value
- 150 ms
Setting: Auto-level
- Value
- Off
Setting: Loudness
- Value
- -14 LUFS
Setting: Can you change it?
- Value
- No
Questions people ask
- Why does my video sound fine in my editor but distorted after upload?
- Because the conversion to MP4 can push loud moments over the maximum, and your editor plays the audio before that conversion. Listen to the exported file on a phone before you post.
- How do I fix distorted audio in a video I already posted?
- Export it again with the peaks lower, then post the new file. Set your limiter to -2 dB. Uploading the same file again changes nothing, and if it crackles in your editor too, record that part again.
- Can I fix audio that crackled when I recorded it?
- Only partly. A declip tool, like the free Clip Fix effect in Audacity, can soften the crackle, but the lost detail does not come back. Recording that part again is the real fix.
- Is distortion the same as my video being too loud?
- No. Loudness is the average over the whole file, and a peak is one moment. A quiet video can distort on one hard sound, and a loud one can be perfectly clean.
- Do I need a true peak meter?
- It helps. A normal peak meter reads the values stored in the file. A true peak meter reads the sound the way a phone will play it, which is where the extra peak shows up.
- Why does my audio crackle only on a phone speaker?
- Because a phone speaker is small and distorts first on loud moments and deep bass. Laptop speakers and headphones hide more of it, so always test on a phone.
Upload one clip of you talking and Cutroom keeps its peaks under -1 dBTP for you. Your first video is free.