How to Use Your iPhone as a 4-Track Recorder

A 4-track recorder captures up to four independent audio tracks that play back in sync. Each track holds a different instrument, vocal or sound. You mix them together to make a finished song.

Classic 4-track recorders from the 1980s used cassette tape. The Tascam Portastudio is the one most people remember. Professional studios ran reel-to-reel machines with 8, 16 or 24 tracks. Modern digital gear like the OP-1 Field revives the tape workflow without the tape. Reel brings that same workflow to your iPhone. No extra hardware needed.

Reel is built around a single jog wheel and tape-style transport controls. You record on one of four tracks. Then you rewind and record the next layer while listening to what you already played.

Every recording is saved as a project with all four tracks kept separate. You can solo, mute, adjust levels and pan. Export the full mix or individual stems.

Open Reel, tap the record button and start playing. You can also start a take without opening the app, from the Action Button, Control Center or Siri, and a rolling buffer catches the moment before the press so the first note is not clipped. The built-in iPhone microphone captures mono audio at 48kHz. Reel converts that to 32-bit float to match the project. Tap stop when you are done. That first take is now on track 1.

To add a second layer, arm track 2 and hit record. Reel plays track 1 back while it records your new performance in sync.

Plug a class-compliant USB audio interface into your iPhone with a USB-C cable or a Lightning to USB adapter. Reel detects the interface automatically and switches its input to it.

An interface opens things up. You can record stereo, connect condenser microphones with phantom power, use instrument inputs and record at 96kHz in 32-bit float. The OP-1 Field works perfectly for this when set to 8ch USB mode.

Overdubbing means adding new material to an existing track. Reel lets you punch in at any point on a track, record your new part and punch out. Everything else stays intact, and the new part lands where you played it, since the round trip through your headphones and back is compensated.

This is how you build a full arrangement one layer at a time. Drums first, then bass, then chords, then melody.

When your project is done, export it as a single stereo mix or as individual track stems. What leaves the app is what you were hearing. The mix, the pitch and any loop you set are printed into the file, and stems come out the same way with muted tracks left out. Reel supports WAV, AIFF and M4A formats. Stems are handy if you want to finish the mix in a desktop DAW.

WAV and AIFF exports are 32-bit float. That preserves the full dynamic range of your recording with zero clipping. M4A uses AAC compression for smaller file sizes.