Guides / Audio formats, quality and file size
Why does my recording sound distorted or clipped on a Mac?
Tested on macOS 26.4.1 (Tahoe), Apple M3 Max, 3 Sept 2026. Updated 2026-09-03.
A distorted, fuzzy or crunchy recording is almost always clipping: the signal reached 0 dBFS, the loudest level a digital file can hold, and the peaks were flattened. It happens at the input gain, before the file is written, and hard clipping cannot be undone afterwards. The fix is to set the gain so the loudest moment stays under full scale, which 24-bit recording makes cheap.
What does clipping actually do to the audio?
Digital audio has a hard ceiling. dBFS means decibels relative to full scale, and "The level of 0 dBFS is assigned to the maximum possible digital level" (Wikipedia, dBFS). Any part of the waveform that would go above it is simply written at the ceiling. The rounded tops of the waves become flat tables, which the ear hears as buzz and grit on every loud hit. Clipping is defined as "a form of waveform distortion that occurs when an amplifier is overdriven and attempts to deliver an output voltage or current beyond its maximum capability" (Wikipedia, Clipping); in a Mac recording the amplifier is the preamp in your interface or the converter itself.
Two things follow. Clipping happens before the file exists, so the file format is irrelevant: a clipped 24-bit WAV is exactly as ruined as a clipped MP3. And it is usually on the loud parts only, which is why a recording can sound fine in the intro and fall apart at the drop.
Where in the chain is it clipping?
Work backwards from the file:
- Interface input gain. The usual cause. A DJ mixer's master or booth output is a hot line-level signal; with the gain knob past halfway most inputs clip on the first kick drum. Watch the interface's clip LED during the loudest part of the set.
- Mic input fed a line signal. Plugging a mixer output into a mic-level XLR input with the preamp up overloads it before the gain knob can help. Use the line or TRS input.
- The source itself. A mixer channel already in the red, or a heavily limited stream, is distorted before it reaches the Mac; nothing on the Mac side fixes that.
- Not clipping at all. Clicks, short gaps and stutter are buffer or connection problems, covered in why is there a gap or dropout in my recording. A thin, muffled voice through AirPods is the Bluetooth headset profile, covered in Bluetooth headphones make Mac recordings sound bad.
System audio captured with ScreenCaptureKit is a digital copy of what the apps play; if that recording is distorted, the source was.
How do I set the gain so it does not clip?
- Play the loudest material you expect, not the soundcheck: the peak of the set, the drop, the shouted line.
- Turn the input gain up until the interface's clip or peak indicator flickers, then back it down until it stops, and then a little more.
- Check the level meter in the recording app on that same passage. It should move well under the top with visible space left.
- Do not touch the gain again during the take. A level change mid-recording is worse than a slightly low level.
Recording at 24-bit is what makes this safe. The theoretical dynamic range is about 146 dB at 24-bit against 98 dB at 16-bit (Wikipedia, Audio bit depth), so leaving a generous margin below full scale costs nothing audible, and you can raise the level later in an editor. At 16-bit a very cautious level starts to expose noise. The comparison is in 16-bit vs 24-bit. Files stay the same size either way: 16.5 MB per minute at 24-bit 48 kHz whether the level is high or low.
Can I fix a clipped recording after the fact?
Not properly. "Complex hard-clipped signals cannot be restored to their original state because the information contained in the peaks that are clipped is completely lost" (Wikipedia, Clipping). De-clip tools in iZotope RX, Adobe Audition or Logic Pro estimate what the missing peak probably looked like and redraw it; on brief, isolated overs that is often good enough to pass, on a whole clipped set it is a lighter shade of broken.
What you can do:
- Lower the volume of the file. This does not remove the flat tops; it only makes them quieter.
- Run a de-clipper on the worst passages and listen critically.
- Check whether a second copy exists. DJ software often records internally at the same time, and a booth recorder or the venue's desk may have a clean take.
- Otherwise, re-record. For a live set that means it is gone, which is why the gain step above is the whole game.
Converting the file to another format never helps and, for MP3, only adds loss; see WAV vs AIFF vs MP3.
Causes of distortion in a Mac recording and whether they can be fixed later
| Cause | What you hear | Where it happens | Fixable after recording | Prevention |
|---|---|---|---|---|
| Input gain too high | buzz and grit on loud parts, flat waveform tops | interface preamp or converter | no (de-clippers only approximate) | set gain on the loudest passage, record 24-bit |
| Line signal into a mic input | distortion even at low gain | interface input stage | no | use the line or TRS input |
| Source already distorted | distortion identical on every playback path | mixer channel, stream, or app | no | fix the source levels first |
| Buffer underruns or USB stalls | clicks, stutter, short gaps | Core Audio driver or cable | no (gaps are missing data) | direct USB port, no hub, disable sleep |
| Bluetooth headset profile active | thin, muffled, narrow-band sound | AirPods or headset mic | no | use a wired or built-in mic |
Every row is a no in the fix column: distortion in Mac recordings is prevented, not repaired.
Where AirCheck fits
AirCheck ($39, macOS 14 or newer) records every take at 24-bit at the device's sample rate, so a DJ feeding a Focusrite Scarlett 8i6 from the mixer can set a conservative gain, watch the level in the app before pressing record, and still have a clean master to normalize later. For system audio the capture is a bit-exact copy through ScreenCaptureKit, so what you hear is what you get, with no analog stage to overload.
When you do not need it: AirCheck has no de-clipper and no editing; a clipped file needs iZotope RX, Audition or Logic Pro. If your source is a microphone and the level is steady, QuickTime Player's audio recording with the gain set once is enough.
AirCheck records what your Mac plays, or any input, to one file. $39 once.
macOS 14 or newer. One-off payment. Fourteen-day refund, no questions asked.
Questions people ask
Why does my recording sound distorted on Mac?
The input level reached 0 dBFS, the top of the digital scale, and the peaks were flattened. It happens in the interface's preamp or converter before the file is written. Lower the input gain while playing the loudest passage and record at 24-bit so a low level costs no quality.
Can you fix clipped audio?
Only approximately. Hard clipping destroys the information in the peaks, so de-clip tools in iZotope RX or Logic Pro estimate a replacement. Brief overs can be hidden; a whole clipped set cannot. Re-recording is the real fix.
Does 24-bit stop clipping?
No, 0 dBFS is the ceiling at any bit depth. What 24-bit does is make it cheap to leave a large safety margin below the ceiling, because the noise floor is far lower (about 146 dB theoretical range versus 98 dB at 16-bit).
Why is my system audio recording distorted when the app sounds fine?
Check playback first: open the file in a different app or on headphones. A ScreenCaptureKit capture is a digital copy of what the Mac plays, so if the file itself is distorted the source stream or app output was already distorted or limited.
Sources
- Wikipedia: dBFS (0 dBFS is the maximum possible digital level)
- Wikipedia: Clipping (audio), definition and irreversibility of hard clipping
- Wikipedia: Audio bit depth (16-bit and 24-bit dynamic range)
- AirCheck: capture format and measured sizes (first-party)
Related guides
- 16-bit vs 24-bit audio recording: which should you choose?
- Why is there a gap or dropout in my Mac recording?
- How to record a DJ mix on a Mac with an audio interface
- Why do my Bluetooth headphones make Mac recordings sound bad?
- How big is an audio recording per minute on a Mac?
- WAV vs AIFF vs MP3: which format should you keep on a Mac?
- Audio formats, quality and file size: all guides
- Every guide, by topic