When you record a meeting with Coii AudioNotes, you get two separate audio tracks: one capturing your voice and the room around you (the microphone input), and one capturing the other person's voice (the system audio from your speakers or headphones). These two tracks are recorded in parallel and stored together in one file. This dual-track approach is what allows the app to tell speaker voices apart later, and why the transcription model can accurately identify who said what.
The trade-off is file size. A one-hour meeting recorded with both microphone and system audio typically takes 120-200 MB of disk space. A 30-minute call takes 60-100 MB. A one-minute recording takes roughly 2-3 MB. This is larger than a single voice memo of the same length because you are storing two audio streams instead of one, and it is larger than a cloud transcription service's compressed audio because the service compresses audio heavily and deletes it after transcription.
Why the file size is what it is
Coii AudioNotes records in AAC format at a bitrate that preserves audio quality for transcription and speaker identification. At this quality level, each minute of audio uses about 2-3 MB per track. Multiply that by two tracks and by the recording length, and you have your file size.
If the app used lower quality audio, the files would be smaller, but the transcription would suffer. If it used higher quality, the files would be much larger but transcription might not improve. The bitrate is tuned to give you good transcription quality without bloating the files unnecessarily.
Cloud services like Otter record at much lower bitrates because they are not keeping the recording. They capture enough audio to transcribe accurately, send it to their servers, transcribe it, then delete the original or store it compressed. You never see the original file size because the service keeps only the transcript.
Coii AudioNotes keeps the original recording on your Mac, so you see the full file size. That is the trade-off for privacy and offline access: your recordings stay with you, and they take up more space than a cloud service's compressed version would.
Checking your total recording storage usage
Open Coii AudioNotes and look at the recordings list. Each recording shows its size. If you have not cleaned up old recordings in a while, you might have accumulated hundreds of hours of audio.
If you record five meetings a week at one hour each, that is 5 × 150 MB = 750 MB per week, or about 3 GB per month. In a year, that is 36 GB. If your Mac has a 256 GB drive and already has the operating system, your apps, and your documents on it, you might be running low on space.
If your Mac has a 512 GB or larger drive, recording is less of a concern unless you record very frequently or for very long sessions.
Deleting old recordings to free space
The simplest solution is to delete recordings you no longer need. If you have a one-year-old recording you have never listened to again, deleting it frees up the space immediately.
Before you delete, ask yourself: Do I still need this recording? Have I transcribed it and saved the transcript elsewhere? Can I recall what this meeting was about? If the answer to all three is no, delete it.
Some users keep recordings for three months, then delete anything older. Others keep one-year archives. It depends on your need for historical recordings. But once a recording is deleted from Coii AudioNotes, the disk space is freed.
Exporting recordings and transcripts
Coii AudioNotes lets you export both the audio file and the transcript. Exporting creates a copy of the file somewhere else — usually on an external drive or cloud storage — but does not delete the original from the app.
If you want to keep a recording for archive purposes but remove it from your Mac to save space, export the audio file to an external SSD, then delete it from the app. The recording still exists on the external drive and you can move it back if needed.
Transcripts can be exported as text files. If you care about the transcript but not the audio, exporting the transcript and deleting the recording saves the most space.
Using an external drive for recordings
If you record very frequently — more than ten hours a week — or need to keep a year-long archive, an external SSD is a practical solution. Connect an external drive, export your recordings to it, and delete them from your Mac. The recordings are still accessible, your Mac has free space, and you can move recordings back to your Mac later if you need to.
An external 1 TB SSD costs $50-100 and gives you room for 5,000-8,000 hours of recordings. This is enough for years of daily meetings.
Comparison to other recording apps
Granola, a competitor that works similarly to Coii AudioNotes, also stores recordings locally and has similar file sizes for comparable meetings. Otter and Wispr Flow use cloud storage, so the file sizes are not visible to you in the same way; the audio is stored on their servers, not on your machine.
The difference is control and privacy. You see every byte your Mac stores; Otter and Wispr Flow do not show you their audio files because the audio lives on their servers. You get larger files but full privacy and offline access; they get smaller local files but upload everything.
Audio quality and file size trade-offs
Coii AudioNotes records at a quality that is optimal for transcription and speaker identification. This is not CD-quality audio, nor is it heavily compressed like a phone call. It is a middle ground: clear enough for accurate transcription, but not so high-quality that the files become unmanageable.
If you wanted to reduce file size further, the only option would be to re-encode the recording to a lower bitrate, which would degrade the transcript quality. This is not recommended.
When a single recording is unexpectedly large
Occasionally a single recording might be larger than expected. This can happen if:
- The recording was longer than you thought. Check the duration.
- The audio quality was unusually high, perhaps because of background noise that increased the bitrate.
- You left the recording running after the meeting ended, capturing extra silence or separate conversations.
None of these are errors; they are just explanations for why a particular recording is larger.
What makes the files worth keeping
Despite their size, the recordings are valuable. They contain both sides of the conversation with perfect accuracy — no guesswork, no missing context, no reliance on a transcription service's interpretation. If a transcription gets a name or a date wrong, you have the original audio to verify what was actually said. If there is ever a dispute about what happened in a call, the recording is proof. For regulated professions like law, medicine, or therapy, having the original audio is often a legal requirement.
The redundancy of two audio tracks is not bloat; it is precision. The microphone track captures your exact voice and tone. The system audio track captures exactly what the other person said, without filtering or compression by a cloud service. Together, they create a complete record of the conversation.
For a lawyer keeping client call records, the file size is a small price for having an uncompressed, locally-stored record that cannot be questioned. For a therapist, the privacy of local storage is worth the 150 MB per hour. For anyone in a regulated field, or for anyone whose calls might become evidence later, the size is not a cost — it is the point.
How file size compares to cloud alternatives
A cloud service like Otter stores your audio on their servers, but they do not show you the file size because you do not own the files. They own them. If you ever lose access to the Otter account, the recordings disappear with it. The "small file size" is an illusion created by heavy compression and deletion.
Coii AudioNotes stores your recordings on your machine, so you see the real size. But you own the files, you control them, and they stay with you for as long as you want to keep them. That ownership is worth the disk space.
Why two tracks enable speaker identification
The second audio track also enables the app's speaker identification feature. Because you have the other person's voice as a separate track, the app can analyze it, build a voice print, and identify when that person is speaking in the transcript. A cloud service that compresses both voices into a single track loses this capability. The extra file size is the cost of this precision.
A single track with both voices mixed makes it harder for a transcription model to distinguish who is speaking. The app has to guess based on voice characteristics, which is less reliable. With two separate tracks, one for you and one for them, the model can be certain about who is speaking at every moment. This is why the transcript accuracy is higher, and why you need the extra storage.
Managing storage as your library grows
If you record regularly, your recording library will grow. A consultant recording five client calls per week creates about 750 MB per week, or 3 GB per month. In a year, that is 36 GB. This matters for Mac storage planning.
Many users with high recording volume use external SSDs as their primary recording storage. They set up Coii AudioNotes to save new recordings directly to the external drive instead of the internal Mac drive. This keeps your Mac's drive free while still giving you access to all your recordings. When you move to a new Mac, you simply connect the same external drive and all your recordings are immediately available.
Another common pattern is to keep the last three months of recordings on your Mac and archive older ones to an external drive. This gives you fast access to recent calls while maintaining a complete archive elsewhere.
Moving recordings between Macs
When you move to a new Mac or want to copy recordings between machines, file size becomes relevant. A one-year archive of daily meetings might be 40-50 GB. Moving this over Wi-Fi can take hours. Using an external drive or wired connection is faster.
Coii AudioNotes syncs your recordings across your three licensed Macs, but this syncing does not move the files; it indexes them. If you need to physically transfer recordings, exporting to an external drive is the fastest method.
What it costs, what it runs on
Coii AudioNotes is $19 once, covering three of your Macs, with a 30-day trial that needs no card and no account. It runs on macOS 13 Ventura or later on Apple Silicon and Intel. Recordings are stored locally on your Mac; nothing is uploaded. How-to-record-a-meeting-on-a-mac covers the recording workflow and where files are stored. How-to-back-up-your-meeting-recordings walks through backing up and moving recordings to external storage, and how-to-export-a-transcript shows how to save just the transcript without keeping the audio file. What-is-system-audio-capture explains why the dual-track recording gives you better transcription accuracy, and offline-meeting-transcription-mac covers the privacy and storage implications of keeping recordings locally rather than uploading them.