The Audio Settings window configures how Pycom handles audio input and output. Open it from Settings → Audio Settings. Which controls are available — and which ones have an effect — depends on how your radio is connected.
Main Window Controls #
The main application window includes three audio controls alongside the main interface:
- Mute: Silences the speaker output immediately. Click again to unmute.
- Volume: Adjusts the overall speaker volume level.
- Settings: Opens the Audio Settings window for detailed configuration of codec, devices, gains, and per-channel controls.
Audio by Connection Type #
Audio behaves differently depending on whether you connect over the network or with a USB serial cable
| Network (UDP) | USB / serial | |
|---|---|---|
| Where audio comes from | The radio streams audio over the network; Pycom processes it in software | The radio's USB codec, bridged through Pycom's monitor path; your microphone is written to the radio's USB MOD input |
| RX Gain | Applies to received audio | Applies to the local monitor path only (what Pycom plays for you) |
| TX Gain | ✔ Applies | ✔ Applies |
| Software audio controls (volume, mute, balance, per-channel, device selection) | ✔ Fully active | Balance, per-channel volume/mute and codec selection do not apply; volume and mute work on the monitor path; device selection applies |
On both connection types, AI Noise Reduction (when enabled) runs once at the head of the receive chain, and its output is shared by playback, the Transcribe window, and the web remote.
Where to Find Each Control #
Audio controls live in several places. This table shows where each one can be adjusted
| Control | Main Display tab | Levels tab | Audio Settings dialog | Radio front panel / CI-V |
|---|---|---|---|---|
| RX Gain | — | — | ✔ | — |
| TX Gain | — | — | ✔ | — |
| Global volume / mute | — | — | ✔ | — |
| Per-band volume / mute / balance | — | — | ✔ | — |
| AI NR | On/off | Strength | — | — |
| Mic Level | — | ✔ | — | MIC level (serial connections) |
| Mod Input Level, AF gain, squelch, NR, RF gain, VOX, etc. | — | ✔ | — | ✔ |
Codec Selection #
Choose between one-channel and two-channel audio codecs:
- One-channel codec: Sends and receives a single audio stream. Use this for simple voice operation where you only need the Main band. Audio is sent to both the left and right speakers.
- Two-channel codec: Sends and receives two independent audio streams simultaneously — the left channel carries Main band audio and the right channel carries Sub band audio. Useful for full-duplex operation where you need to hear both main and sub receivers.
Switch between one-channel and two-channel at any time — no reconnect is needed.
Stereo controls (balance, left/right volume, left/right mute) are automatically disabled when the one-channel codec is selected.
Channel Routing #
In two-channel mode, the audio is split across left and right:
- Left channel: Main band audio
- Right channel: Sub band audio
Use the stereo balance slider to adjust the relative level between Main (left) and Sub (right). Each channel also has its own independent volume and mute control.
Device Selection #
- Speaker Device: Choose which audio output device Pycom uses to play received audio.
- Microphone Device: Choose which audio input device Pycom uses to capture your transmitted audio.
RX Gain #
RX Gain boosts the audio you receive, over a range of 0 to 36 dB. The default of 0 dB leaves the audio untouched (unity gain).
- Where: Audio Settings dialog only.
- Scope: stored per radio and per connection type — the same radio keeps a separate setting for network and USB connections.
- Applied after AI Noise Reduction, so you boost the denoised signal, not the noise.
RX Gain affects only what you hear — it never changes the signal that goes to the air.
On a network connection, RX Gain pairs well with AI NR: denoise first, then boost the result.
TX Gain #
TX Gain boosts the audio you transmit, over the same 0 to 36 dB range with a default of 0 dB (unity).
- Where: Audio Settings dialog only.
- Scope: per radio and per connection type, like RX Gain.
- What it touches: your transmitted voice audio only. It is applied to the pure audio just before it is sent to the radio.
Start at 0 dB and increase in small steps while watching the ALC meter — too much TX gain can overdrive your transmitted signal.
The Signal Paths, in Plain English #
If you are trying to work out which control is affecting your audio — or why one is not — it helps to know the order things happen in.
Receive: radio → your speakers
- The radio's own AF gain, squelch, NR and RF gain shape the audio first (radio front panel or Levels tab).
- The audio travels to your computer — over the network, or via the radio's USB codec into Pycom's monitor path.
- AI Noise Reduction, if enabled — the first software stage, applied to the shared received stream. Playback, the Transcribe window and the web remote all hear the same denoised audio.
- Pycom applies the mute.
- Then the global volume.
- In two-channel mode (network connections), per-band volume, mute and balance.
- RX Gain — the last stop before your ears.
- Your chosen speaker device.
Transmit: your microphone → the radio
- Your voice is captured by Pycom's global microphone device (the one selected in Audio Settings) on both connection types.
- TX Gain is applied — composed with the web remote's own gain/mute stage when a web TX transmission is in progress.
- On network connections the audio is sent to the radio over the LAN; on USB/serial it is written to the radio's USB codec-out, feeding the radio's USB MOD input (drive level set by the Mod Input Level on the Levels tab).
Technical Signal Chain Reference
For power users: the exact order of operations in Pycom's audio processing. The radio's own controls (AF gain, squelch, NR, RF gain) always act first; everything below is Pycom's software chain.
Receive chain #
Network (UDP): radio AF/SQL/NR/RF → network transport → AI NR → software mute → global volume → per-band volume/mute + balance (two-channel) → RX Gain → output device. AI NR sits at the head of the software chain — one instance feeds playback, the Transcribe window and the web remote alike. RX Gain still sits after AI NR — you boost the denoised result, not the noise.
USB / serial: radio AF/SQL/NR/RF → USB codec → AI NR → monitor path: mute → RX Gain × volume (composed) → output device. Per-band and balance controls do not apply.
Transmit chain #
Network (UDP): global microphone device → TX Gain → radio MOD input (LAN). TX Gain applies to pure audio (PCM) only — protocol packets are never touched.
USB / serial: global microphone device → TX Gain → USB codec-out → radio USB MOD input. Drive level into the modulator is set by the radio's Mod Input Level (Levels tab).
Transmissions keyed from the built-in web remote include one additional gain stage of their own, composed with TX Gain (and mirrored web mute) at the same point in the chain.
See also: the Levels tab for radio-side level sliders, AI NR for noise reduction, and the radio setup guide for connection types.