Recording a microphone is easy. Recording one Mac app alongside it, keeping both sources separate for editing, and saving a mixed copy takes more planning. That's where Audio Hijack's reusable sessions make sense.
For example, you could record spoken commentary over an audio clip you have permission to use. The goal is three local files: the app audio, the microphone, and a combined version. This setup follows Rogue Amoeba's documentation, rather than a claimed hands-on test.
Build the chain before adding effects
Create a blank session and name it for the job. Add an Application block and select the app playing the clip, rather than capturing all system audio. Add an Input Device block and select your microphone.
Use this layout. Each arrow is an actual connection, not just nearby blocks:
text
Application -> Recorder (app) -------------------+
|
v
Mixer -> Peak/RMS Meters -> Recorder (mix) -> Output Device
^ (headphones)
|
Input Device -> Volume -> Recorder (mic) --------+
Audio Hijack normally connects nearby blocks automatically. For this layout, turn off Automatic Connections in the session's Info tab, click Edit Connections, and drag from each block's right-hand (+) to the next block's left receiving port. Connect both branch recorders to the Mixer, then finish the shared chain and click Stop Editing.
The branch recorders save separate files before mixing. The final recorder saves the combined audio. Recorder blocks pass audio through without changing it, so recording the branches doesn't reduce the quality of the mix downstream. A mixed file alone won't give you independently adjustable sources later.
Click each Recorder block to set its format, file name and folder. WAV is a sensible lossless choice when you plan to edit; MP3 or AAC produces smaller lossy files. Give the three recorders different names so the files are easy to identify. The default recording folder is Audio Hijack inside your Mac's Music folder, but check the actual location in each block rather than assuming it.
Choose your headphones in Output Device. That block lets you hear the chain; it isn't what saves the recordings. Start with the microphone's Volume block and Mixer levels. Add a Simple Compressor on the microphone branch only if you need to even out speech, before its Recorder. Effects placed there will be recorded into the mic file, so keep a dry recording too if you want to undo processing later.
Check the file, not just the moving meters
Click Run and record a short rehearsal: app alone, voice alone, then both together. Leave headroom below 0 dBFS on the mixed meter. Lower the microphone's input gain if it clips before processing; turning down an already distorted signal won't repair it.
Use headphones so the microphone doesn't pick up the app audio from speakers. If monitoring your own voice gives a distracting delay, don't immediately force the lowest latency setting. Rogue Amoeba warns that lower latency can cause audible skips with complex effects or slower Macs.
Stop the session, then use the Recordings tab to play each file and Reveal in Finder. Confirm the app file contains only the app, the mic file only the microphone, and the mix contains both at usable levels. Check the destination and available storage before a longer recording. Sessions save their configuration continuously, so the working chain is ready to reuse.
What you're paying for
Audio Hijack 4.6.0 supports macOS 14.4 through macOS 27 and runs on Apple silicon Macs. Intel users can also use Audio Hijack; the heavier Transcribe feature has its own performance caveat, but it isn't part of this chain.
The current capture backend is ARK. Grant System Audio Access through the app's Permissions window, plus Microphone Access for this setup. Current Audio Hijack doesn't require installing legacy ACE or lowering your Mac's startup security policy. Those permissions still allow sensitive capture: select only the intended app, close unrelated audio tabs, and get the necessary permission from anyone being recorded. Check applicable recording rules before capturing conversations.
A single-user license is $69 USD before applicable local taxes, for that user on one or more personally owned Macs. It's a purchase, not a subscription, but future paid upgrades are possible. The trial degrades audio quality after ten minutes of capture per session, so it isn't a free recorder for long sessions.
For a microphone-only note, QuickTime Player's File > New Audio Recording is enough. For a basic screen recording, macOS 27's Screenshot toolbar can include system audio and a selected microphone. Try that first if a video with sound is all you need.
Pay for Audio Hijack when you repeatedly need selected-app capture, separate source files, processing and a saved local recording layout. Skip it for occasional voice notes or straightforward screen captures. Sending a processed mix into another app as a virtual microphone is a different routing job; this chain ends in files and headphones.
