AV Matrix Switcher Product

Overview

An AV matrix switcher routes any of N video sources to any combination of M displays at once. It is the central nervous system of a conference center, sports bar, lecture hall, or broadcast facility: every source — PCs, media players, cameras, codecs — lands on an input, every display and projector hangs off an output, and the matrix holds the live routing state. Unlike a simple switcher, the crosspoint is non-blocking: all eight outputs can show eight different inputs, the same input, or any pattern between, simultaneously.

The hard engineering is not the routing logic, which is trivial, but doing it to signals that are 18 Gbps serial streams wrapped in encryption, negotiated per-link, and carried over field wiring of unknown quality.

The crosspoint core

At the center is the Crosspoint Board, whose Crosspoint ASIC switches each input's TMDS or FRL lanes — up to 6 Gbps per lane — to any set of outputs without decoding the video. Routing at the serial-stream level keeps latency under a frame and the pixel data bit-exact. The cost is signal integrity: every connector, trace, and switch stage adds jitter, so per-port Retimers re-clock the stream against a low-jitter Clock Generator reference at each boundary. Retimer quality is the practical difference between a matrix that runs 4K60 reliably and one that produces intermittent sparkle on long runs.

Inputs: equalize, decrypt, lie about the display

Each HDMI Input Card port starts with an HDMI Receiver IC receiver that adaptively equalizes whatever 5–15 m of HDMI cable delivered and decrypts HDCP 2.3. The subtler component is the EDID Emulator: in a point-to-point HDMI link the source reads the display's EDID and negotiates a format, but in a matrix the "display" changes every time routing changes. The matrix therefore presents each source a managed, stable EDID — typically the lowest common denominator of the connected sinks, or a fixed 4K60 profile — so sources never renegotiate mid-show. EDID policy is the single largest cause of matrix misbehavior in the field, which is why it lives in the control processor's policy engine rather than in jumpers. ESD Protection arrays guard every pair, because hot-plugging field wiring is the product's daily electrical abuse.

Outputs: scale, re-encrypt, and reach 100 m

The Output Card solve the two problems the crosspoint ignores. First, format: a per-output Output Scaler converts the routed stream to each sink's native resolution, so one 4K source feeds a 1080p confidence monitor without dragging every display down — and because the scaler re-times the output, switching on scaled ports is seamless rather than a two-second resync. Second, distance: HDMI cable is unreliable past about 15 m, so commercial outputs ship as HDBaseT. The HDBaseT Transmitter PHY modulates uncompressed video, Ethernet, IR, and RS-232 onto ordinary Cat6 as PAM-16, reaching 70–100 m, and the PoH Injector powers the far-end receiver over the same cable so a ceiling projector needs no local mains. The HDMI Transmitter IC path re-encrypts with each sink's HDCP keys; the matrix is a licensed HDCP repeater, decrypting once at the input and re-encrypting per output.

Control and audio

The Control Processor owns everything stateful. Its Compute SoC Module runs the Control Firmware that exposes routing over Telnet, REST, and a web UI on the Ethernet Port; in practice most installs are driven by a room control system (Crestron, AMX, Q-SYS) through those APIs or the RS-232/IR Ports, which also tunnels serial and IR to HDBaseT far ends. The Front Panel buttons remain the fallback when the control network is down.

The Audio Section reflects how commercial buildings are wired: video goes to displays, but audio goes to a separate DSP and amplifier chain. The Audio DSP de-embeds PCM from any routed input, downmixes multichannel, applies per-output delay so audio through the building DSP stays lip-synced with video through the scaler, and hands balanced +4 dBu analog to Phoenix Terminals via the DAC Stage. Breakaway routing — sending input 3's audio with input 5's video — is a standard requirement.

Power and packaging

PoH makes the power budget unusual: the Power Section must be sized for every output simultaneously powering a far-end receiver, pushing an 8×8 toward 150 W. Installs where a dead matrix darkens a building specify the hot-swap Redundant PSU, load-shared through ORing diodes and supervised by Rail Monitors that raise SNMP traps. The 1U–2U Rack Chassis uses a Card Cage of field-swappable I/O cards — the modularity that distinguishes this class from fixed-configuration boxes — cooled by temperature-controlled Cooling Fans that earn their keep in the sealed credenzas integrators insist on using.

The category sits between two alternatives: fixed HDMI switchers below it, and AV-over-IP systems above it, which replace the crosspoint with encoders, decoders, and a 10 GbE network switch. AV-over-IP scales past 64×64 and reuses network infrastructure, but the dedicated matrix still wins on latency, determinism, and not requiring the AV integrator to run a multicast network — which is why both architectures continue to ship in volume.