> ## Documentation Index > Fetch the complete documentation index at: https://docs.nomn.jp/llms.txt > Use this file to discover all available pages before exploring further. # Record Stems > One audio file per part, in the room's channel format, folded to stereo, or mono # Record Stems **Stems** records RESERVOIR's own sound engine to one WAV file per part, plus the drum kit, the full mix and the MIDI that played. The files line up sample for sample, so a DAW session built from them plays back the take as you heard it. Stems capture the audio RESERVOIR renders itself. If you only use RESERVOIR to send MIDI to other instruments, record those instruments in your DAW instead. ## Making a take 1. Click **v** beside **Stems** and choose a format (below). The choice is kept for the session. 2. Click **Stems**. Recording starts at once. The strip over the visualizer reads **REC STEMS** with the elapsed time and a level meter of what is being captured. 3. Play. 4. Click **Stems** again to stop. The strip reads **STEMS TAIL** while reverb and delay ring out: recording continues until the mix falls below -60 dBFS, or 10 seconds at most, so no tail is cut off. 5. The strip then reads **Saved N stems (C ch) to** the take folder, with **Reveal** and **Copy path** buttons. ## Formats | Format | Channels per file | Use it for | | - | - | - | | **Per part stereo (layer taps, outputs 1-2)** | 2 | A stereo session. Each file holds what that part sends to outputs 1 and 2. | | **Per part mono** | 1 | Single-speaker positions, or re-placing each part yourself. Every speaker channel of the part is summed into one. | | **Room format (N ch per part)** | one per room output | A multichannel session. Each file has the bound room's channel layout, and the part files plus Kit add up to Mix. | | **Fold room to stereo** | 2 | A stereo deliverable from a multichannel room. Every note is kept, including notes placed on speakers beyond 1 and 2. | With a stereo room bound, the room formats give the same files as **Per part stereo**. Per part stereo only holds outputs 1 and 2. On a room with more speakers, a note placed on speaker 3 or higher is missing from that file. Choose **Room format** or **Fold room to stereo** whenever the room has more than two outputs. ## Include * **FX stem (when shared)**: the shared reverb and delay return. RESERVOIR only writes it when it has to save CPU during a heavy take. From that point the part files are dry, and the reverb and delay are in this file. * **Kit**: the drum kit, with its own reverb and delay. * **Mix**: the final output. * **Performance.mid**: the notes of the take. ## Destination By default each take goes to a new folder in `~/Music/RESERVOIR Stems`, named with the date, time and preset. **Choose folder...** sets a different place. **Ask every time** shows a save dialog when you start. **Keep silent layers** is off by default, so parts that played nothing leave no file. ## Files in a take * `L01 .wav` to `L64 .wav`: one file per part that played, numbered by part. * `Kit.wav`, `FX.wav`, `Mix.wav` when included. * `Performance.mid` when included. * `info.txt`: preset, room, sample rate, format and the peak level of each file. ## Warnings while recording * **Room has 16 outputs, device has 2: you will hear outputs 1-2 only.** The bound room uses more outputs than your audio device has. The files still hold every channel of the room, but you only hear part of it. * **Capture is very quiet: Mix peak -45 dBFS after 2 s.** Little sound is reaching the stems. Check the levels and that the room you bound is the one you mean to use. * **N host blocks larger than the prepared size not captured.** The host sent a larger audio buffer than it announced. Those blocks are missing from the files. Set the host buffer size before recording. ## Stem Outs in a DAW In the VST3 and the Instrument AU, **Stem Outs** turns on extra output buses: Layer 1 to Layer 12 and Kit, each stereo. Your DAW records them like any multi-output instrument. Parts above 12 share a bus (part 13 with part 1, and so on). Stem Outs is off by default because every bus adds CPU load. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.