Why send audio stems instead of a single MP3?
Stems are not a finished song. Vocals, drums, bass, and harmony are separate recordings. The mixing engineer layers them in their own software. If you convert everything to one MP3, there’s nothing left to open separately.
One minute of 24-bit, 48 kHz stereo audio takes about 17 MB. A four-minute stem is roughly 70 MB. With eight stems to send, you exceed Gmail’s 25 MB limit on the very first file. WhatsApp compresses audio and doesn’t transfer folders.
The mixing engineer needs the separate files you prepared.
| Method | What happens | Suitable for mixing? |
|---|---|---|
| Gmail or Outlook attachment | Attachments over 20–25 MB won’t send | No |
| Compresses audio; doesn’t transfer folders | No | |
| Converting to a single MP3 | Separate recordings are combined and can’t be separated again | No |
| Shared drive | Files can be stored, but the recipient may need an account | Use with care |
| SendGB link | Stems and folder structure download unchanged | Yes |
The example above is a stem package for one song. For a finished stereo master, see the guide to sending audio files. For a podcast episode, cover art, and notes, see the guide to sharing podcast files.
What should you include in a stem folder?
An incomplete folder means an incomplete mix. If the vocals arrive but the drums are left in another email, the recipient can’t put the song together.
| Recording | Purpose | Without it |
|---|---|---|
| Vocals | Lead vocals and any backing vocals | The song has no lyrics |
| Drums | Kick, snare, and room recordings, or a single drum stem | The rhythm can’t be built |
| Bass | Bass guitar or synth bass | The low end is missing |
| Harmony | Guitar, keyboards, pads | The song lacks its foundation |
| Reference MP3 | An example of the intended sound | The mix has no target |
| Notes | Tempo, key, and what each file contains | File names may not be enough |
If you use subfolders, keep them intact. If vocals, drums, and bass are separate, add the whole folder. The structure stays intact when the recipient downloads the entire transfer.
No ZIP is needed. If you create a ZIP, we don’t extract the archive.
Project files and stems are not the same thing
An Ableton, Logic, Cubase, or Pro Tools file is a session. Stems are playable recordings exported from that session. They serve different purposes.
If you add the project file, it transfers too. We don’t open it. If samples are outside the project folder and you don’t include them, the recipient will have silent tracks. We don’t supply what’s missing.
If another studio is handling the mix, the most reliable approach is to export each audible group as a WAV stem and send it with a reference MP3.
| Stems | Project file | Finished song | |
|---|---|---|---|
| What it is | Separate WAV recordings | Ableton, Logic, or Pro Tools session | Stereo master |
| What the recipient does | Mixes in their own software | Needs the same software and all samples | Listens or masters |
| Can anything be missing? | No, if the folder is complete | Yes, if external samples aren’t sent | No, it’s a single file |
| Covered on this page? | Yes | Transfers as a file; we don’t open the session | See the audio file guide |
Is 5 GB enough for a stem package?
5 GB is often enough for one song. It isn’t always enough for an album or a full day’s recordings. The limit is based on total size, not track count.
| What you’re sending | Typical size | Which option works? |
|---|---|---|
| One song, eight to ten stems, and a reference | Often 1–2 GB | Free; up to 250 MB stays available for up to 90 days, larger transfers for 7 days |
| A long track with many groups | May approach 5 GB | Free if it fits |
| Stems for a ten-song album | May exceed 5 GB | SendGB Extra |
| A full day’s multitrack recordings | Tens of GB | SendGB Extra, 500 GB per transfer |
| Archive over 500 GB | Over 500 GB; one-time transfer | SendGB Exceed, up to 1 TB |
SendGB Extra starts at €29.90 per year. It includes 1 TB of storage. SendGB Extra keeps files for up to 1 year. It suits producers and studios that send stems frequently.
SendGB Exceed requires no subscription. A 1 TB transfer costs €9.99. The code can be used once and is valid for 1 year. SendGB Exceed transfers stay available for 7 days. It is enough for an occasional very large archive.
How to send
- 1
Add your stem folder
Add the stem folder to the upload box on the homepage, not just a single song. Vocals, drums, bass, and the reference MP3 go in the same transfer. The free limit is 5 GB total.
- 2
Send the link
Email the link to the mixing engineer, or copy it and paste it into a message. Add a password if you want. Send the password separately from the link.
- 3
The recipient downloads the folder
The recipient downloads from the link and does not create an account. Downloading the entire transfer preserves the folder structure. Free transfers over 250 MB stay available for 7 days. Free transfers up to 250 MB stay available for up to 90 days. SendGB Extra keeps files for up to 1 year.
What happens to your file?
- Each stem downloads in the WAV format you uploaded. The sample rate and bit depth don’t change.
- Vocals, drums, bass, and harmony stay in separate files. They aren’t converted to a single MP3.
- When you add a folder, its structure stays intact. The recipient downloads everything together.
- If you set a password, anyone with the link still needs the password to download.
What we don’t do
- We don’t mix stems or convert them to MP3 or any other format.
- We don’t open Logic, Ableton, or Pro Tools projects. We don’t supply missing samples.
- Stereo WAV and reference MP3 files can be played on the download page. Don’t expect this for multitrack session files.
- There is no Gmail or Outlook add-on. You paste the link yourself.
Frequently asked questions
Are stems converted to a single MP3 when I send them?
No. Vocals, drums, bass, and other recordings download as separate files. SendGB doesn’t layer them into a single song. If you upload 24-bit WAV files, they download as 24-bit WAV files.
What are stems, and how are they different from a master?
A master is the finished stereo song. Stems are its separate parts. The mixing engineer opens the vocals and drums separately. To send a finished song, see the guide to [sending audio files](/send-large-files/send-large-audio-files). This page is for separate recordings.
Which files should I send together?
Vocals, drums, bass, guitar or keyboard recordings, and a reference MP3 should be in the same folder. Include the tempo and song notes as text, too. If you send a file in a separate email, the mixing engineer’s stem folder will be incomplete.
Will the folder structure stay intact?
Yes. If vocals are in one subfolder and drums in another, keep that structure and add the whole folder. The structure stays intact when the recipient downloads the entire transfer. No ZIP is needed. If you create a ZIP, we don’t extract the archive.
Can I send an Ableton, Logic, or Pro Tools project?
If you add the project file, it downloads as a file. We don’t open the project. If the song’s samples are outside the project folder and you don’t include them, they’ll be missing on the recipient’s end. If you’re unsure, export each audible recording separately as a WAV stem.
Is the free 5 GB limit enough for a stem package?
5 GB is often enough for eight to ten stems from one song. One minute of 24-bit, 48 kHz stereo audio takes about 17 MB. A four-minute stem is roughly 70 MB. Stems for a ten-song album may exceed 5 GB. A full day’s multitrack recordings reach the limit faster. We don’t guarantee a recording duration or file count.
Can I send stems through Gmail or WhatsApp?
No. Even a single stem may exceed the 25 MB attachment limit. WhatsApp compresses audio and doesn’t transfer folders. Create a transfer and paste the download link into an email or message.
Can recipients listen before downloading, and do they need an account?
Stereo WAV and MP3 files can be played on the download page. The recipient downloads from the link and does not create an account. They need their own recording software to mix the files. SendGB is not mixing software.
Can I send a reference MP3 and stems in the same transfer?
Yes, and you should. The reference shows what the mix should sound like. It doesn’t replace the stems. Sending only an MP3 does not provide the separate recordings.
Which option can handle stems for an album?
A single song often fits within the free 5 GB limit. Free transfers over 250 MB stay available for 7 days. Free transfers up to 250 MB stay available for up to 90 days. Album stems or a full day’s recordings need SendGB Extra: 500 GB per transfer, 1 TB of storage, starting at €29.90 per year. SendGB Extra keeps files for up to 1 year. For a single archive over 500 GB, SendGB Exceed is enough: no subscription, €9.99 for a 1 TB transfer, and a single-use code valid for 1 year. SendGB Exceed transfers stay available for 7 days. You can add a password. Send the password separately from the link.
Send a download link instead of attaching stems to a chat one by one
One song’s stems may fit within 5 GB. Album stems and a full day’s recordings can go up to 500 GB with SendGB Extra, or up to 1 TB in a single transfer with SendGB Exceed.
Start sending