k2k audio The toolkit drawer. Gain staging, mixing, envelope following, trimming — the practical nodes that tie everything else together.
Gain
What it does — Raises or lowers the level of a signal, with an optional normalize mode that brings the peak to a fixed reference.
When you’d reach for it — Something came out of a chain too quiet or too hot and you need to fix the level before it hits the next node. Or you have wildly different sources you want brought to the same ballpark before mixing.
Quick example
- Connect your source into Gain.
- Set Gain to +6.0 dB to push a quiet recording up.
- If levels are unpredictable, flip Normalize on instead — the node finds the loudest peak and scales everything to a consistent level.
Parameters
| Parameter | What it controls | Range | Sweet spot hint |
|---|---|---|---|
| Gain | Level boost or cut applied to the signal | -60 — +24 dB | 0 dB is unity; stay within -12 to +12 for most mixing tasks |
| Normalize | Scales the signal so its peak hits a fixed reference level | On / Off | On when combining sources with very different loudness |
Mixer
What it does — Sums multiple inputs into a single mono output with per-channel gain, mute, and solo controls plus a master fader.
When you’d reach for it — You have several parallel branches in your graph — an extracted layer, a rejected layer, maybe a texture pass — and you need to fold them back into one signal with precise level balance.
Quick example
- Connect two or three sources into the Mixer’s input channels.
- Solo channel 0 to hear just that source, then adjust its gain to -3 dB.
- Un-solo, bring up channel 1, mute channel 2 if it is not needed yet.
- Set Master to -1.5 dB to leave headroom.
- Turn on Average if you want the sum divided by the number of active channels to prevent clipping.
Parameters
| Parameter | What it controls | Range | Sweet spot hint |
|---|---|---|---|
| Channels | Number of input ports available | 1 — 32 | Start with 4, add more as needed |
| Master | Output level applied after summing | -60 — +12 dB | Keep at 0 dB unless the sum is too hot |
| Average | Divides the sum by the number of active inputs | On / Off | On when mixing many sources to tame the buildup |
| Per-channel Gain | Individual level for each input | -60 — +12 dB | -3 to -6 dB per channel keeps headroom when summing several |
| Per-channel Mute | Silences a channel without disconnecting it | On / Off | Quick A/B comparison — mute one layer, listen to the rest |
| Per-channel Solo | Isolates a channel so only it is heard | On / Off | Use to focus on a single layer while tweaking |
Stereo Mixer
What it does — Mixes multiple mono inputs into a stereo pair with per-channel pan, gain, mute, and solo, using equal-power panning.
When you’d reach for it — You have several mono spectral layers and you want to place each one in a stereo field before sending the result to the output. Think of it as the final bus where everything gets a position and a level.
Quick example
- Connect three processed layers into the Stereo Mixer.
- Pan channel 0 to -60 (left of center), channel 1 to 0 (center), channel 2 to +60 (right of center).
- Pull channel 2 down to -4 dB so it sits behind the others.
- Solo channel 1 to check it sounds clean on its own, then un-solo.
- Adjust Master to taste — the Left and Right outputs carry your final stereo signal.
Parameters
| Parameter | What it controls | Range | Sweet spot hint |
|---|---|---|---|
| Channels | Number of input ports available | 1 — 16 | Match to the number of layers you are combining |
| Master | Output level applied to both L and R after summing | -60 — +12 dB | 0 dB unless summing many sources |
| Per-channel Gain | Individual level for each input | -60 — +12 dB | Balance layers relative to each other first, then set Master |
| Per-channel Pan | Stereo position for each input | -100 (hard left) — +100 (hard right) | Spread sources across the field; keep the anchor element near center |
| Per-channel Mute | Silences a channel without removing it | On / Off | Quick way to test “with and without” |
| Per-channel Solo | Isolates a channel | On / Off | Useful for checking panning and level in isolation |
Envelope Follower
What it does — Reads the amplitude contour of an incoming signal and outputs an envelope that other nodes can use for sidechain modulation.
When you’d reach for it — You want a kick drum’s loudness shape to drive the gain of a pad, or you want the energy of a vocal to modulate a filter on a synth layer. This node turns audio dynamics into a control signal any modulatable parameter can subscribe to.
Quick example
- Connect the signal you want to track (e.g., a kick loop) into Envelope Follower.
- Set Detection to Peak for fast transients, or RMS for smoother tracking.
- Dial Attack to 5 ms and Release to 150 ms for a punchy pump shape.
- Give the Slot Name a label like “Kick Env” so you can find it easily from other nodes.
- On the target node, right-click a parameter and choose Sidechain, then select “Kick Env.”
Parameters
| Parameter | What it controls | Range | Sweet spot hint |
|---|---|---|---|
| Detection | Measurement mode — Peak reacts to transients, RMS follows energy | Peak / RMS | Peak for drums and percussive sources, RMS for pads and vocals |
| Attack | How fast the envelope rises when the signal gets louder | 0.1 — 500 ms | 1—10 ms to catch transients; 30—80 ms for a gentle swell |
| Release | How fast the envelope falls when the signal gets quieter | 1 — 2000 ms | 100—300 ms for musical pumping; longer for ambient swell |
| Normalize | Scales the envelope so its peak reaches 1.0 | On / Off | On when using as a modulation source, so depth controls are predictable |
| Slot Name | Label for the envelope in the sidechain registry | Text | Name it after the source (“Kick Env”, “Vocal Dyn”) for clarity |
| Filter Mode | Frequency targeting before detection — Off, Lowpass, Highpass, or Bandpass | 4 options | Bandpass around 80—200 Hz to track only the kick in a full mix |
| Cutoff | Center or cutoff frequency for the targeting filter | 20 — 20 000 Hz | Match to the fundamental of the source you are tracking |
| Q | Resonance / bandwidth of the targeting filter | 0.1 — 10.0 | 0.7 for a broad focus; 3—5 to isolate a narrow band |
Trimmer
What it does — Cuts a segment out of the incoming audio by setting start and end points, and optionally shapes the result with an ADSR amplitude envelope.
When you’d reach for it — Your source file is longer than the section you actually need, or you want to carve a one-shot from a longer recording and give it a clean fade-in and fade-out so it plays back without clicks.
Quick example
- Connect a loaded audio file into Trimmer.
- Drag the start marker to 500 ms and the end marker to 2000 ms in the waveform viewer.
- Enable Envelope and set Attack to 15 ms and Release to 80 ms for smooth edges.
- Leave Sustain at 100% so the middle of the clip is untouched.
- The output is a clean 1500 ms segment with shaped fades.
Parameters
| Parameter | What it controls | Range | Sweet spot hint |
|---|---|---|---|
| Start | Beginning of the trimmed region | 0 ms — source duration | Drag in the waveform viewer for visual precision |
| End | End of the trimmed region | Start + 1 ms — source duration | Keep some margin before the very end of the file |
| Enable Envelope | Turns ADSR shaping on or off | On / Off | On for one-shots and samples; off if you just need a clean cut |
| Attack | Fade-in time at the start of the trimmed region | 0 — 5000 ms | 5—20 ms removes clicks; longer for swells |
| Decay | Time from peak to sustain level | 0 — 5000 ms | 30—80 ms for a natural transient shape |
| Sustain | Steady-state level during the held portion | 0 — 100% | 100% to keep the body intact; lower for plucked or percussive shapes |
| Sustain Hold | Duration the sustain level is held before release begins | 0 — 5000 ms | 0 ms lets it flow naturally into release |
| Release | Fade-out time at the end of the trimmed region | 0 — 5000 ms | 30—100 ms for a clean tail; longer for pads |