--- title: 'zeroTX + zeroRX — Secure Audio over IP' url: 'https://zerodab.com/software/zerotx-zerorx' markdown: 'https://zerodab.com/software/zerotx-zerorx.md' date: '2026-10-07' description: 'Secure Audio over IP zeroTX + zeroRX A single solution, two applications: zeroTX sends studio-quality audio over the IP network, while zeroRX receives it and plays it out at the destination — encrypted, bit-perfect and monitored in real time. The receiver is free. Contac…' --- Secure Audio over IP # zeroTX + zeroRX A single solution, two applications: **zeroTX** sends studio-quality audio over the IP network, while **zeroRX** receives it and plays it out at the destination — encrypted, bit-perfect and monitored in real time. The receiver is free. [Contact us ](https://zerodab.com/contact) [See the components](#components) **2 in 1**transmitter + receiver **8**receivers at once **2.5**Mbit/s per receiver **< 5 ms**latency on a local network The solution ## A complete audio link, from source to speaker **zeroTX + zeroRX** is a single solution delivered as two applications that work together. It turns any IP network — local, radio link, fibre or VPN — into a professional audio link, with no long audio cables and no expensive dedicated hardware. #### zeroTX — transmits It takes audio from your computer’s input (line, audio interface, mixer) and sends it, encrypted, to one or more receivers. You see everything in one window: who is connected, link quality and statistics. #### zeroRX — receives It runs at the destination, connects to the transmitter by itself and plays the audio on the selected output. It can also run in verification mode, with no playback, counting packets and bit errors. **Free.** #### A key set up only once Each receiver has its own key; you copy it once into zeroTX when you add the receiver. From then on, connecting and reconnecting are automatic. #### Bit-perfect or lossless Two transport modes: identical to the source, or intelligently compressed with less traffic. In both cases, what arrives at the receiver is identical to the source. How it works ## Four steps, then you forget about it #### Install both applications **zeroTX** on the source computer and **zeroRX** at every destination. Windows, macOS or Linux — no account, no mandatory internet. #### Copy the receiver’s key Each zeroRX displays its public key. You hand it over once to whoever operates zeroTX, when adding the receiver. #### Press “Transmit” zeroTX connects to each receiver by itself and starts sending the audio stream, encrypted end to end. #### Monitor Audio level, shared aligned clock, lost packets, bitrate — in real time, at both ends of the link. Link diagram ## The operating flow, from source to speaker **zeroTX is the master of the link**: it decides the audio format, the codec and the transport. **zeroRX follows** — it learns the format from the session and adapts by itself. The dotted line is not a separate connection: configuration, telemetry and clock synchronisation travel inside the same encrypted session. #### TX decides, RX adapts The audio format, the codec (PCM or lossless FLAC) and the transport (UDP or TCP) are set once, at the transmitter. #### Session encrypted end to end Mutual authentication: a receiver refuses an unknown transmitter and vice versa. Keys are generated locally, on first run. #### Heals itself Adaptive FEC and a jitter buffer for network losses; if the link drops, the session is rebuilt automatically. #### One transmitter, several receivers Each receiver has its own session, key and statistics — up to 8 at once, added or stopped while running. ### Inside each application The audio goes through the same steps at both ends, in reverse order: **zeroTX** captures, (optionally) normalises, encodes, encrypts and sends; **zeroRX** receives, authenticates, recovers losses, decodes and plays out — or verifies bit by bit, with no playback. ### The life of a session The link is born, holds and rebuilds itself. Pairing happens once (the receiver’s public key), then everything is automatic: mutual authentication, format negotiation, encrypted streaming. If losses appear, adaptive correction steps in; if the link drops completely, the session is rebuilt without your intervention. Solution components ## The two applications, in detail ### Component 1 — zeroTX, the transmitter **Secure Audio over IP** — sends studio-quality audio over your IP network to one or more zeroRX receivers: encrypted, lossless, with automatic protection against network losses. - **Audio without compromise** — bit-perfect (no change at all) or losslessly compressed (same quality, less network traffic) - **To several destinations at once** — one transmitter can feed up to **8 receivers** (more rooms, relays or control rooms) - **Secure from the start** — each receiver has its own key; only the authorised transmitter can send to a receiver - **Automatic protection against network losses** — intelligent compensation and automatic adaptation; for networks that block regular traffic there is an alternative transport mode - **Complete monitoring** — VU meters with peak hold and clipping detector, clock synchronisation with the receiver, traffic statistics and logs - **Professional dynamics (optional)** — EBU R128 chain with normalisation or limiting, for a constant broadcast level - **Built-in test source** — a reference signal for verifying the link, bit by bit - **Simple to use** — English and Romanian interface, no account, no complicated setup ![The zeroTX interface: active transmission to two receivers — VU meters, synchronised clock, statistics](https://zerodab.com/software/zerotx-zerorx/zeroTX-transmisie-activa-EN.png) The zeroTX interface: active transmission to two receivers — VU meters, synchronised clock, statistics. ### Component 2 — zeroRX, the receiver free The receiving end of the solution. It runs on the computer at the destination, listens to the network and, when the transmitter connects, takes the audio, rebuilds the stream and plays it out on the output device you choose. It can also run in **verification mode** — with no playback — when you only want to confirm that the link is perfect. - **Install it and forget about it** — it connects to the transmitter by itself, and reconnection is automatic if the link drops - **Playback or verification** — choose the audio output for playback, or the “no playback” mode, which counts packets and **bit errors** - **Secure** — it only accepts the authorised transmitter (the key is set up once) - **Complete monitoring** — output VU meters, clock synchronisation state, packets received / lost / recovered, average bitrate - **Adjustable smoothing buffer** — for fluctuating networks, increase the buffer and the audio flows without interruptions - **Automatic start** — it can start together with the computer, ideal for unattended destinations - **Low resource usage** — it runs well even on mini PCs or modest computers - **Free** — for as many destinations as you need ![The zeroRX interface: active reception — output VU, clock “Aligned”, packets received with no losses](https://zerodab.com/software/zerotx-zerorx/zeroRX-receptie-activa-EN.png) The zeroRX interface: active reception — output VU, clock “Aligned”, packets received with no losses. Who it is for ## Who uses zeroTX + zeroRX #### Radio stations and studios The audio link between studio and transmission sites, or between rooms — including as a backup for a dedicated link, up and running in seconds. #### Sound crews The same mix to the main hall, the second stage, the video control room or the stage monitor desk — without miles of analogue cable. #### Institutions and places of worship Audio from the main hall to secondary rooms, simultaneous translation, foyer — without running analogue signal through the whole building. #### Companies and campuses Announcements and audio programmes between buildings, over the existing network, with destinations that need no technical staff. #### Engineers and integrators Test links, measurements and bit-perfect verification — the “no playback” mode is an objective diagnostic instrument. Scenarios ## Situations where it does the job ### Studio → transmission site The studio in one building, the transmission equipment in another. A computer running zeroTX in the studio and a mini PC running zeroRX at the destination — bit-perfect audio over the existing IP network, monitored in real time. ### One studio, several destinations The same audio programme to 3–4 points: two relays, a backup room and a monitoring position. You add each receiver once and transmit once to all of them, up to 8 at a time. ### The same programme, several rooms In a church, school, conference centre or airport: one zeroRX receiver in every room, on a mini PC or on the existing computer. Each room with its own output level. ### Simultaneous interpretation One transmitter in the main hall and one receiver in each room: people in the secondary rooms hear exactly what happens in the hall, including the interpretation. ### Testing a network Before a big event: the test source in zeroTX plus zeroRX in verification mode. The application shows lost packets and bit errors — “bit errors 0” means a perfect link. ### Mobile studio / temporary link Broadcasting from a temporary location (laptop, hotspot, 4G + VPN) to the headquarters, or a receiver on a laptop at the destination: it installs in minutes, whether they are on the same network or over a VPN. Requirements ## What you need to get started The requirements are the same for both applications. Only the audio side differs: zeroTX needs an audio **input**, zeroRX needs an audio **output** (or the “no playback” mode). | Requirement | Minimum | Recommended | |---|---|---| | **Operating system** | Windows 10 (64-bit) · macOS 10.13 (Intel) or macOS 11 (Apple Silicon) · modern Linux (64-bit) | Windows 11 · macOS 12+ · Ubuntu 22.04+ | | **Processor** | 64-bit, 2 cores | 64-bit, 4 cores or more | | **Memory (RAM)** | 2 GB | 4 GB or more | | **Disk space** | ~50 MB | — | | **Network** | 100 Mbit/s | 1 Gbit/s, wired connection | | **Display** | 1024×600 | 1280×720 or larger | | **Audio** | audio input (zeroTX) or audio output / no playback (zeroRX) | dedicated audio interface | ### Useful details - **Traffic:** ~2.5 Mbit/s per receiver in bit-perfect mode; ~1.5 Mbit/s with lossless compression. For 3 bit-perfect receivers, ≈7.5 Mbit/s leaves the transmitter. - **Ports:** by default **39000/UDP** (must be allowed in the firewall at the receiver; also TCP if you use the alternative transport mode). - **Latency:** 1 ms packets + a ~4 ms smoothing buffer (adjustable); the real latency is visible live, in milliseconds, in the clock bar. - **Resource usage:** ~100 MB of memory, under 20% of one processor core (measured at 48 kHz / 24-bit). - **Installation:** the kit is ~9 MB, the installation takes ~25 MB; on Windows it is per user, **with no administrator rights**. - **Automatic start:** the receiver can start together with the computer — ideal for unattended destinations. - **Internet:** not required. The solution works on any IP network; the internet only matters if the destinations are remote and not on the same network. Frequently asked questions ## What people ask most What exactly is zeroTX + zeroRX? A single solution for audio transport over the IP network, delivered as two applications that work together: **zeroTX** (the transmitter, installed at the source) and **zeroRX** (the receiver, installed at the destination, free). Together they form a complete audio link. How many receivers can I transmit to at once? Up to 8, each with its own stream, its own key and its own statistics in the panel. Does the audio arrive identical to the source? Yes. You can transmit in bit-perfect mode (no change at all) or losslessly compressed — in both cases, what arrives at the receiver is identical to the source. With the built-in test source you can verify it bit by bit, using the error counter in zeroRX. Do I have to pay for the receiver too? No. **zeroRX is free** and can be installed on as many destinations as you need. How much traffic does it use? About 2.5 Mbit/s per receiver in bit-perfect mode and around 1.5 Mbit/s with lossless compression (stereo audio 48 kHz / 24-bit). Each receiver has its own stream. What happens if the network loses packets? zeroTX protects the stream automatically (adaptive error correction) and reports what is happening in real time. For networks that block regular traffic there is also an alternative transport mode, which can be enabled from the interface. Is it encrypted? Yes. Each receiver has its own security key; only the authorised transmitter can send to it. Traffic is encrypted end to end, including on public networks or over a VPN. Do I need internet or an account? No. It works on any IP network: local network, radio link, fibre or VPN. No account, no registration, no mandatory internet. What audio source can I use for transmitting? Any input of the computer: sound cards, USB audio interfaces, mixer outputs. For testing, the application includes a reference signal. Can I adjust the audio level? Yes: VU meters with peak hold and a clipping detector on the input, and you can optionally enable a professional dynamics chain (EBU R128 normalisation or limiting). On reception you have output VU meters and an adjustable smoothing buffer. What is the “no playback” mode? A professional verification mode: the receiver produces no sound, but counts everything that arrives — packets received, lost, recovered and bit errors. With the test signal from zeroTX, you can confirm that the link is bit-perfect. Does it reconnect by itself if the link drops? Yes. When the transmitter comes back, the connection is re-established automatically, without your intervention. The receiver can also start automatically together with the computer. Which systems does it run on? Windows, macOS and Linux — including mini PCs and modest computers. The interface is available in English and Romanian, with more languages to follow. How do I start? Install zeroTX on the source computer, zeroRX at the destination (the receiver is free), copy the receiver’s key into zeroTX once and press “Transmit”. Write to us and we will send you the applications together with a step-by-step getting-started guide. ## Want an audio link on your IP network? We will send you the applications and the installation guide, step by step. [Contact us ](https://zerodab.com/contact) --- ## Navigation - Parent: [Software](https://zerodab.com/software.md)