Sample rate is how many times per second a Mac measures an analog sound wave to turn it into a digital audio signal, most often 44,100 times a second (44.1kHz, the CD-quality standard) or 48,000 times a second (48kHz, the rate most video and pro audio software uses). Every audio device runs at a rate of its own, and every app expects one too, and mismatches between them are one of the most common causes of audio problems on a Mac.
This page is about what sample rate actually is, not a troubleshooting walkthrough. If you already know that and just want the fix for crackling speakers or a stuttering grouped output, see the two applied guides linked further down. Here, the goal is to explain the underlying concept those fixes both depend on.
How sample rate turns sound into digital audio
Real sound is a continuous wave, air pressure rising and falling smoothly over time. A computer can't store something continuous, so it takes snapshots: it measures the height of that wave at regular, extremely short intervals and stores each measurement as a number. Sample rate is simply how often it takes those snapshots. A higher sample rate means more snapshots per second, which means the digital copy can follow the original wave's shape more closely.
This is different from bit depth, which controls how precisely each individual snapshot is measured, not how often they're taken. Sample rate is about time; bit depth is about precision at each point in time. Both affect audio quality, but they're separate settings, and Audio MIDI Setup's Format dropdown shows both together, for example "44100.0 Hz, 24-bit".
44.1kHz and 48kHz, and why both exist
44.1kHz became the standard in the early 1980s when engineers chose it for the original audio CD, and it's still the default for most music files and streaming services today. 48kHz became the standard separately, for video and broadcast, mainly because it divides more evenly into common video frame rates, which makes it easier to keep picture and sound in sync during editing. Most conferencing apps, screen recorders, and video editors default to 48kHz for the same reason.
Neither rate is objectively better for everyday listening. They're two standards that grew up in different industries and never merged, which is why a Mac ends up juggling both: a music app sending 44.1kHz audio, a video call sending 48kHz audio, and a speaker or interface that has to accommodate whichever one shows up.
Every device and every app has its own rate
Every audio device on a Mac, built-in speakers, a USB interface, a pair of AirPods, reports a native sample rate it prefers to run at, visible in Audio MIDI Setup's Format dropdown for that device. Every app sending audio has a rate it's built to send at too, based on the source material or the standard for its category. Most of the time this is invisible, because macOS quietly matches the two up or converts between them without you noticing.
Every feature free for 30 days. No account, no card details.
Download for MacWhat happens when sample rates don't match
When an app's rate and a device's rate disagree, macOS has to resample the audio on the fly, converting one rate into the other before it reaches the speaker. Done cleanly, that conversion is inaudible. Done badly, or repeated across several devices at once, it's a common source of clicks, pops, and brief dropouts. This is exactly what's happening in the two most common audio complaints on a Mac: we've covered the applied fix for crackling or popping speakers and for a stuttering Multi-Output Device in separate guides, both of which walk through checking for exactly this mismatch. This page exists to explain the mechanism behind both, rather than repeat those steps.
How to check a device's sample rate in Audio MIDI Setup
Open Audio MIDI Setup, in Applications > Utilities. Select any device in the list on the left, and look at the Format dropdown along the bottom of the window. It shows the rate that device is currently running at, and clicking it lists every rate the device supports, usually including 44.1kHz and 48kHz and sometimes higher options like 88.2kHz, 96kHz, or 192kHz for professional interfaces. This dropdown is the same place both applied guides above point to, because it's the one control that actually sets a device's rate.
When several devices are combined, in a Multi-Output Device or any other grouped output, checking that every member device shows the same Format is one of the most common real fixes for problems that only appear once devices are combined. A single device running alone rarely causes a mismatch; a group built from devices with different native rates is where it usually shows up.
Where Chorus fits, and where it doesn't
Chorus groups outputs using the same mechanism macOS already provides for a Multi-Output Device, and adds a single working volume for the group. It doesn't set, change, or manage sample rate: that's a system-level setting each device reports, and Audio MIDI Setup is the only place to view or change it. Chorus's own interface has no control for it, by design, because it isn't an audio-processing app.
If a group you've built in Chorus has a rate mismatch between its members, the fix is the same as it would be for any Multi-Output Device: open Audio MIDI Setup and match the Format on each device, as covered above. Once the rates match, Chorus makes rebuilding or switching to that group faster on every use after, but the rate itself stays entirely outside Chorus's own controls.
For the step-by-step on building a Multi-Output Device, see Apple's own guide to Audio MIDI Setup.
Frequently asked questions
What is sample rate in audio?
Sample rate is how many times per second a Mac measures an analog sound wave to turn it into a digital audio signal. It's expressed in Hertz (Hz) or kilohertz (kHz): a 44.1kHz sample rate means the wave is measured 44,100 times every second. The more measurements per second, the more precisely the digital version can represent the original sound.
What is the difference between 44.1kHz and 48kHz?
44.1kHz (44,100 samples a second) is the CD-quality standard, chosen in the early 1980s and still the default for most music files. 48kHz (48,000 samples a second) is the standard for video, streaming, and most professional audio software, because it divides more evenly into common video frame rates. Neither is objectively better for everyday listening; they're just two different standards that different kinds of software default to.
Why does a sample rate mismatch cause crackling or stuttering on a Mac?
When two devices expect different sample rates, or an app sends audio at a rate a device isn't running at, macOS has to convert between them in real time before playback. That conversion is usually inaudible when done cleanly, but a device juggling several sample rates, or a Multi-Output Device made of members with different native rates, is more likely to produce the clicks, pops, or brief stutters people notice as crackling audio.
How do I check or change a device's sample rate in Audio MIDI Setup?
Open Audio MIDI Setup from Applications > Utilities, select a device in the list on the left, and look at the Format dropdown at the bottom of the window. It shows the device's current sample rate and lets you pick a different one from the rates the device supports, typically 44.1kHz, 48kHz, and sometimes higher rates like 96kHz or 192kHz.
Does Chorus control or change a device's sample rate?
No. Sample rate is a setting each audio device reports and Audio MIDI Setup controls at the system level, not something Chorus's own interface shows or changes. Chorus groups outputs and sets a working volume for the group; if a group's members are running at different sample rates, that still needs fixing in Audio MIDI Setup, the same as it would for a Multi-Output Device built without Chorus.
