When streaming audio through an interface connected to your Mac, there are many factors that can cause performance problems such as:
- audio artifacts such as pops or clicks, stutters, or dropouts as you play or record
- bit crushed audio sound
- excess latency
- distortion in previously recorded audio
- distortion in recorded files that was not heard on hardware input monitoring
- erroneous firmware messages, performance issues, or other strange behavior
- device disconnects
Use this guide to optimize your Mac computer to reduce the chances of this from happening, or as a starter if you have any issues.
Please keep in mind these steps are not required to use our product, but have solved problems for customers in the past. It is best to test these known fixes first and see if they relate to your issue.
Turn off Automatic Sleep Mode
In Apple Menu System Preferences Energy Saver set Computer Sleep to Never.
Make sure “Put hard disks to sleep when possible” is NOT checked.
(These settings may vary on different Mac Models) 
This will mean that Sleep Mode does not come on automatically, but you can still put your computer to Sleep when you like, by going to Apple Menu Sleep.
This is one of the most important steps to prevent problem behavior with an audio device because Sleep Mode works by suspending drivers in a hibernate state, rather than unloading them fully. When waking up the computer does not “enumerate” the drivers fresh as with a newly connected device, but just attempts to proceed as if nothing changed.
However your Audio Device will think it has been disconnected during Sleep, as the driver was no longer available. During Sleep the unit may shut off or go into a standalone mode depending on it’s model/design/features. When the computer wakes from Sleep the Audio Device doesn’t receive a good connection because the driver is not reloaded fresh as with a true unplug/replug, called “driver enumeration.”
Automatic Sleep can lead to situations where you get up for a quick break during your session and come back to glitchy audio, artifacts, no audio, a full disconnect, and other performance issues. Very short Sleep Mode settings, such as every 1 minute, can even create situations where you turn to do something in the studio like adjust your outboard mixer and before you are done the whole unit has been disconnected, or an erroneous firmware message has popped up.
If you must use Sleep Mode, then for best performance first turn off/unplug your interface and then choose Sleep from the Apple Menu. When you come back to work you can Wake the computer and then plug in/power the interface and get a freshly loaded driver.
Remove or Disable Unused Network Adapters
In Apple Menu System Preferences Network and make sure to remove any Network Adapters you are not currently using for a LAN or Internet Connection.
For example remove “Bluetooth PAN” “Thunderbolt Bridge” “Firewire” et al.
Having a port that shares a USB, Firewire or Thunderbolt Bus with your Audio Hardware here can limit its bandwidth.
When a certain Port Type, for example “BlueTooth PAN” is listed here, but not in use the computer will constantly “ping” that Port, looking for a connection to appear. This can create a lot of Network Traffic where it isn’t needed, such as on your USB Bus, since BlueTooth is an internally connected USB Device. This can lead to those constant pings knocking your audio device off the USB Bus, disconnecting it.
Turn off your Firewall
In Apple Menu System Preferences Security & Privacy Firewall make sure Firewall is Off.
Networking is one of the most common sources of audio problems on all computers, Mac and PC. This could be Network Activity on the computer, but also Firewalls for specific programs or computer blocking connections. In general it is best to disable the Firewall on any Audio Production computer.
If you do have important Firewall tasks that need to be done, like opening a Port Forward for your Video Games, it is best to do this on your Router instead, as that device is better equipped. It won’t cause so many audio interactions when done on a different device.
More about the differences between Hardware and Software Firewalls here.
https://www.fortinet.com/resources/cyberglossary/hardware-firewalls-better-than-software
A hardware firewall provides several benefits:
Can be used to intelligently control the traffic that reaches your server
Can be configured with specific rules for all traffic
Can ease the burden on other server resources. For example, you can disable software firewalls, which can free up much-needed memory and processor power
Remove Startup Items
In Apple Menu System Preferences Users & Groups Admin Account Login Items: remove any Startup items.
Startup Items can be control panels for other audio gear, like Digidesign loader, or programs like Spotify that go online and can interrupt other audio programs. Also things like Adobe Creative Cloud, or even Anti Virus Software will run in the background and slow down your computer.
In this screenshot you can see the computers has iTunes, Flux a color temperature program, and Dropbox all starting up when the computer loads. As iTunes and Dropbox can go online in the background, and Flux may affect graphics performance, these could all potentially affect audio or CPU performance negatively. It is best to remove them if having audio troubles.
There are no Startup Items by default on the Mac so you can remove all of them with no issue. If you are worried about removing some items, then take a screenshot of them so you can restore them at a later time: https://support.apple.com/en-us/HT201361
Repair Disk Permissions
In Applications Utilities Disk Utility: select Macintosh HD and click First Aid (Repair Disk Permissions on older Macs). Repeat this for any other Hard Drives you have connected.
Choose your best USB or Thunderbolt Port and cable
If you are using a USB Audio Interface (such as Duet), try all the USB ports on your computer. One may work better than another due to how the internal ports are hubbed.
Be sure you have tried another USB, Thunderbolt or Firewire Cable.
To get to this page to view your layout of currently connected devices go to Apple Menu > About this Mac > System Report > Choose USB or Thunderbolt based on the type of interface you have.
Turn off Analytics and Location Services
In System Preferences Security & Privacy Privacy Tab Analytics (could say Diagnostics and Usage), un-check the boxes for Share Mac Analytics, Share with App Developers, and Share iCloud Analytics.
You may also want to disable Locations services found in this same Privacy Tab to further reduce background network traffic.
Turn off Sound Notifications for Apps
Turn off sound notifications for all your apps: In System Preferences Notifications, select an app then un-check the box for “play sound for notifications. Repeat this for all apps in the left side-bar.
Turn off Automatic Updates
Automatic Software Updates can cause a lot of issues for recording computers and should DEFINITELY be disabled. This will allow you to see what update the Mac is wanting to install, and choose when and if you run it. Reasons for this:
1 - Major Updates - (example, Mojave to Catalina, 10.14 to 10.15.) - Before any Major OS update you will need to check that your audio software and hardware is compatible with the new version. All of us major audio companies need time to test and release a new update for each product, to be compatible with the new OS. So you don't want your computer to automatically install a new OS the first moment it goes live from Apple, in case your DAW or Audio Device is not yet compatible. You could wake up one morning and suddenly nothing works! Always check for compatibility with your audio hardware/software brands before a Major Update.
2 - Minor Updates - (example, security patches, supplemental updates, 10.15.4 to 10.15.5) - Some of these updates may run in the background, while you are working. So if you are in a recording session, and really need all your computer's resources and then a security update starts in the background without you knowing you may get glitches and stalls.
As an example, look at how many times the update called XProtectPlistConfigData ran for this customer over the last few years. Numerous times per month, at all random times of day or night. This could easily contribute to unexpected glitches at seemingly random times.
To disable your Automatic Updates, go to Apple Menu > System Preferences > Software Update.
Here UNCHECK Automatic Software Updates.
Now, you will get prompts at the upper right of your Mac when Updates are available. You can click to see what those updates are, review if you are ready to update for them based on compatibility, and choose to run them when you are not recording.
After these steps please RESTART the Computer
While you are Recording
- Check that any Virus Scanners or Backup software (i.e. Hightail or Carbonite) that run in the background are disabled. High background activity especially over the Network can cause glitches.
- Close any unnecessary applications while recording (i.e. Skype or Browsers you are not actively using.)
- Be sure that you record to a separate Hard Drive from your System/OS drive. More information: https://www.bhphotovideo.com/explora/pro-audio/tips-and-solutions/save-your-music-the-basics-of-hard-drives-for-audio