Sound¶
The show machine has one audio output, shared by the whole show. This page covers choosing it, setting levels per clip, reading the meters, and which outputs carry sound.
Everything Moonshine plays converges on a single master bus — both clips during a crossfade, whichever playlist is running, every surface. That bus goes to two places at once: the show machine's own audio device, and embedded inside every output that is a video stream. There is no per-projector volume and no second soundtrack.
Sound comes out of the show machine, not out of your browser
The live picture your browser shows is picture only — it carries no audio at all, on any device, however good the connection. Monitor at the show machine, or on whatever is receiving your NDI or SDI feed.
The one exception is the preview player on the Assets tab. That plays the file itself, locally, through your own speakers, with its own controls. It tells you the clip has an audio track. It tells you nothing about what the show is putting out.
Choose the output device¶
- Open the Settings tab.
- Stay on the Machine sub-tab.
- Find the Audio section.
These are machine settings, not project settings — they stay put when you switch projects, because they describe the box you are standing next to rather than the show running on it.
Opening Settings claims the machine
Moonshine takes the machine lock as soon as you open the Settings tab and releases it when you leave. While another operator has that tab open, every control in this section is dimmed and read-only for you, and the machine cannot be edited from two places at once. See Locks.
Driver¶
Two, always both, in the same order:
| Driver | What it is |
|---|---|
| DirectSound / CoreAudio | The driver every machine has, and the default. One label serves both platforms; on a Windows show machine it means DirectSound. |
| ASIO | The manufacturer's low-latency driver, if the interface ships one. |
A driver this machine cannot offer stays in the list, greyed out, carrying the machine's own explanation — hover it to read the reason. Nothing disappears, because an option that vanishes leaves you unable to tell not supported here from I am looking in the wrong place.
Changing driver clears the chosen device. A device name belongs to its driver, and carrying an ASIO interface name into DirectSound produces a setting that saves cleanly and then fails when the show tries to make a sound. Pick the driver first, the device second.
An ASIO device belongs to one application at a time
ASIO drivers take the card exclusively. If another application on the show machine already holds the interface, Moonshine cannot open it, and vice versa.
Device¶
The list is exactly what this machine reported when Moonshine asked it. Moonshine builds a real audio output, cooks it, and reads back the device list the vendor's driver fills in — there is nothing to type, and nothing is guessed. If a device is not in the list, the machine did not report it.
Two behaviors that look like bugs and are not:
- Until you pick something, the box reads No output — silent. The machine's own speakers stay closed, and a note says so. Stream outputs still carry audio — see Which outputs carry sound.
- A saved device the machine no longer reports stays selected, labelled (missing), with a warning underneath. Moonshine does not quietly fall back to the first device on the list, because on a machine that was swapped or re-cabled that would re-point a show at the wrong output and say nothing.
Re-scan after you plug something in
Re-scan devices asks the machine to enumerate again — that is how a USB interface or a new card gets into the list without a restart. Scanning creates and cooks operators, so it is limited to once every ten seconds; a press inside that window hands back the list it already has. If a device you just connected is not there, wait ten seconds and press it again.
Buffer¶
How much audio the machine keeps queued ahead of the card.
| Setting | Use it when |
|---|---|
| 5 ms — lowest latency | Lip-sync matters more than anything and the machine is not busy. |
| 10 ms | |
| 20 ms — default | The starting point. |
| 50 ms | |
| 100 ms — safest | The machine is rendering hard and you are hearing crackles. |
It is a trade, not a preference. The output is delayed by the buffer, so shorter is tighter sync with the picture and more risk of a dropout when the machine gets busy; longer survives a heavier show at the cost of a few milliseconds of delay. Start at 20 ms and only move if something is actually wrong.
A free Non-Commercial TouchDesigner license blocks this
Non-Commercial asks for confirmation before an application touches an audio device, and that dialog opens on the show machine, where nobody is standing to click it. The result is a device that never opens and a show that runs silent. See What you need.
Master volume¶
A single 0–100% level for the whole machine, applied to the bus before it splits.
Master volume changes what your streams carry
The same fader feeds the speakers and the audio embedded in every NDI and SDI output. Pulling it down to work quietly in the room also pulls down what a receiver downstream is recording. To listen quietly, use the machine's own volume control, the mixer, or the amp — not this.
The bus is clamped at full scale before it goes anywhere, so an over-hot mix cannot overdrive an embedded stream. That is a safety net, not headroom: a master meter sitting at the top means the levels feeding it should come down.
Reading the meters¶
Three meters sit under the master volume: Master, Deck A and Deck B. Moonshine plays a playlist through two decks so one clip can fade into the next, and Deck A and Deck B are simply those two — during a crossfade, both move.
They update once a second and are drawn as they arrive, with no smoothing between readings. Each one shows its loudest channel as an average level, so a stereo pair with one dead side still reads high rather than hiding the fault at half.
A bar goes red at 95% of full scale.
No meters is not the same as no sound
The meters only exist while an audio device is open. With no device chosen, the panel reads Levels appear once an output device is playing — and your NDI and SDI outputs are still carrying audio the whole time. A meter that sat at zero would be indistinguishable from a device playing silence, so Moonshine shows nothing instead of showing a zero.
The two halves of the meter stack read the signal at different points, which is what makes them useful together:
| What you see | What it means |
|---|---|
| A deck meter moves, Master does not | Master volume is at 0. Deck meters are read before it; the master meter after it. |
| Nothing moves, and the panel says levels will appear later | No device is open. Pick one under Device. |
| Meters move, room is silent | The signal is leaving Moonshine. The problem is past it — the wrong device, a muted mixer channel, an amp. |
| A warning under the meters | The machine reported a fault; it prints the machine's own words. |
Set the level of a clip¶
Every playlist row carries a speaker button and a level box, between the length box and the ⋮ menu.
| Control | Behavior |
|---|---|
| Speaker button | Mutes that clip. The icon turns red while it is muted. |
| Level box | 0–100%, stepping in fives. Disabled while the clip is muted. |
Muting leaves the level alone, so un-muting brings back the number you had set rather than jumping to full.
Both take effect straight away on a clip that is already playing — you do not have to re-trigger it. Both are stored with the project and shared with everyone on the show, like the rest of the playlist.
A clip with no level set plays at full. That is what makes playlists built before this release come back with sound instead of coming back silent.
Why the level is on the clip and not on the bus
Through a crossfade, two clips are audible at once. A single fader on the master bus would apply the incoming clip's level to the outgoing one as well, so a quiet clip arriving would duck the clip it was replacing. Putting the level on the clip keeps it with the clip, all the way through the transition.
Sound across a transition¶
Audio follows the transition on the same clock as the picture. The outgoing clip fades down while the incoming one fades up, over exactly the transition's duration — a Dissolve · 0.6s is a 0.6-second audio crossfade, and a Cut (0 s) is an instant swap. There is nothing to configure.
The fade is equal power, not a straight line: the two levels are shaped so that their combined loudness stays constant through the middle of the crossfade. A linear fade of both clips audibly dips halfway; this one does not.
See Transitions for choosing the shape and the duration.
What actually has sound¶
| Source | Audio |
|---|---|
| Video file | Its own audio track. A file with no track plays silent. |
| Still image | None. |
| NDI source | The sender's audio. |
TouchDesigner component (.tox) |
Only if the component exposes an audio output. Silent until it does. |
| Spout source | Never. Spout shares picture between applications and carries no audio at all. |
Everything is resampled to 48 kHz
48 kHz is what SDI and ST 2110 want, and the conversion preserves the running time, so a 44.1 kHz file plays at its proper pitch rather than being sped up.
Which outputs carry sound¶
| Output type | Sound |
|---|---|
| The machine's audio device | Always — that is the master bus, at the device you chose above. |
| NDI output | Yes, embedded in the stream. |
| SDI output | Yes, embedded in the stream. |
| Display output | No. A rectangle on a display is not a stream; the machine's audio device is the local path. |
Outputs that are a stream carry an Audio checkbox on the output card, next to Enabled. It is on by default, and an output from a project saved before this release counts as on — those shows come back with sound rather than coming back silent. Clear the checkbox on any output that should carry picture only.
A Display output has no such checkbox, because there is nothing to embed it in.
Embedded audio does not need anyone logged in
Stream outputs are re-pointed at the master bus once a second whether or not a browser is connected, so a show machine running on its own with every laptop packed away still puts sound on its NDI and SDI feeds.
When there is nothing to hear¶
Work down this list. It is ordered by how often each one is the answer.
- Is the clip muted, or at 0%? Look at the speaker icon on the playlist row — red means muted.
- Does the clip have sound at all? Preview it on the Assets tab and listen. A file with no audio track, a still image, and any Spout source are all silent by design.
- Are the meters moving? Open Settings → Machine → Audio.
- A deck meter moves but Master does not — master volume is at 0.
- Nothing at all, with Levels appear once an output device is playing — no device is open; go to step 4.
- Is a device chosen? No output — silent in the Device box means the machine's own speakers are closed. Pick a device.
- Does the device say (missing)? The machine no longer reports it. Pick one that is in the list, then check the cabling on the one that vanished.
- Did you just plug something in? Press Re-scan devices, wait ten seconds, press it again if it has not appeared.
- For a stream: is the output's Audio checkbox on? An output can carry perfect picture with the audio deliberately switched off.
- Past Moonshine. Meters moving and a device open means signal is leaving the machine — check the machine's own volume control, which output the cable is actually in, and the mixer or amp at the other end.
- Check the show machine's screen. Its status panel carries an
Audio:line naming the device that is open, or reading no output device with the reason. It is the fastest way to answer "is this machine even trying" without a browser. - Check the TouchDesigner license. On a Non-Commercial license there may be a confirmation dialog waiting on the show machine's desktop, blocking the audio device from ever opening.
And the one that catches everybody once: your browser is not going to play it. The picture you are watching carries no sound.
Where to go next¶
- Transport controls — start a playlist, and wire it to a surface first
- Transitions — the transition duration is also the audio crossfade duration
- Outputs — where a projector's picture lands
- Troubleshooting — the rest of what goes wrong on site