TWS: about and terms¶
JP150PCB 1.3PCB 1.4since 26.9.0Jan PřibyslavskýThis page does not apply to the product or PCB revision chosen in the header.
Two JP150 units can play the same audio from a single Bluetooth host, with no cable between them. This feature is called True Wireless Stereo (TWS). Both units must run the same firmware version, 26.9.0 or newer, and the matching MuraLink.
About TWS¶
Normally a host (for example a smartphone) connects to one amplifier over Bluetooth, and that amplifier plays the audio. With TWS, two amplifiers work as a pair:
- The host connects to only one of them: the Primary unit.
- The Primary plays the audio and also relays it wirelessly to the second unit: the Secondary.
- Both units play in sync, so you can drive two speakers, or speakers in two rooms, from one host.
- The two units remember each other. After the first pairing you do not need to pair them again: every time they are switched on, they find each other automatically.
In the current firmware both units play the full stereo signal. To make one unit play only the left channel and the other only the right channel, configure the channel routing on each unit separately, for example in its ADAU1452 DSP program.
Terms¶
| Term | Meaning |
|---|---|
| TWS (True Wireless Stereo) | Two Bluetooth audio devices linked so that they play audio from a single source in sync. |
| Unit | One JP150 amplifier module. The procedures refer to the two units of a pair as unit A and unit B. |
| Host (Bluetooth host) | The Bluetooth audio source, such as a smartphone or PC. |
| Peer | The other unit of the pair. From the point of view of unit A, unit B is its peer, and vice versa. |
| Primary | The unit that the host connects to. It receives the audio from the host, plays it, and relays it to the Secondary. |
| Secondary | The unit that receives the audio from the Primary instead of from the host. |
| Pairing (bond) | The stored link information that allows the two units to recognise and reconnect to each other. Each unit keeps its own copy in the non-volatile memory of its Bluetooth module, so the pairing survives power cycles. Clearing the pairing on one unit does not clear it on the other. |
| Remembered peer | The peer whose pairing is stored on a unit. A unit with a stored pairing is said to remember its peer. |
| TWS capability | The main TWS on/off switch of a unit. When TWS is disabled, the unit works only as a standalone Bluetooth amplifier. The setting takes effect immediately but is not retained after a restart: at every power-up the unit sets it automatically, based on the remembered peer and the Fallback role. |
| Fallback role | The role that a unit takes at power-up if it does not remember a peer: Standalone (TWS is not used), Primary (factory default: the unit actively searches for a unit to pair with) or Secondary (the unit waits to be found by a searching unit). The Fallback role applies only when no peer is remembered. If a peer is remembered, the unit reconnects to it and ignores the Fallback role. |
| Current role | The role that the unit currently has in the active TWS link: Primary, Secondary, or Unknown if no peer information is available yet. |
| Boot outcome | Records what happened to TWS at the unit's most recent power-up (status values). |
| TWS status | The live state of the link to the peer (status values). |
| Peer memory | The list of paired devices stored in a unit's Bluetooth module. It contains both the hosts that you have paired and the TWS peer, which is marked in the list. MuraLink shows this list in the Peer table. |
Prerequisites¶
- MuraLink on a Windows PC, the version that matches the unit firmware. MuraLink communicates with one unit at a time, so you configure the units one after the other.
- Firmware 26.9.0 or newer on both units (Firmware updates).
- Two JP150 modules, each with a power supply and speakers connected, and two USB-C data cables (charge-only cables do not work).
- Recommended: an external Bluetooth antenna on each module, for better range.
- A smartphone or other Bluetooth audio source (the host).
No additional hardware setup is required for TWS. Place the two units within Bluetooth range of each other, and the Primary within range of the host.
Tip
Put a small label on each unit (for example "A – Primary" and "B – Secondary") so that you always know which unit the host connects to.