SDI Amplifiers & Splitters

SDI (Serial Digital Interface) is a professional uncompressed video standard that runs over 75-ohm BNC coaxial cable. It was designed specifically for the broadcast industry. SDI carries uncompressed video, multi-channel embedded audio (up to 16 channels), timecode, and metadata over a single coax cable for 100 meters or more, with no licensing or HDCP handshake, no encoding artifacts, and no negotiation delay between source and destination. Those properties make it the standard in live production where any glitch is unacceptable: cameras, recorders, switchers, and monitors all need a clean copy of the signal at all times, and SDI delivers that with rugged consumer-grade reliability.

There are five mainstream variants, each step up doubling bandwidth. SD-SDI carries 270 Mbps for standard-definition video. HD-SDI carries 1.485 Gbps (suitable for 1080i and 720p). 3G-SDI carries 3 Gbps (1080p60). 6G-SDI doubles that to 6 Gbps and supports 4K30 in single-link mode. 12G-SDI carries 12 Gbps and supports full 4K UHD at 60 Hz over a single cable. A 12G-SDI distribution amplifier is backward compatible with all earlier rates, which is useful when migrating a facility from older to newer SDI infrastructure in stages.

SDI distribution is built for long distances over coaxial cable with no content protection; HDMI distribution is for shorter copper runs with HDCP negotiation. An SDI DA assumes pro broadcast infrastructure: BNC connectors, 75-ohm coax, cable runs of 50 to 200 meters, no copy-protection handshake, and uncompressed signal with embedded audio and metadata. An HDMI splitter assumes consumer or commercial AV infrastructure: HDMI connectors, much shorter cables, HDCP handshakes for protected content, and EDID management for displays with different capabilities. Each is the right tool in its own world: broadcast and live production use SDI, AV integration uses HDMI.

The maximum cable distance depends on the SDI rate. SD-SDI can run 300 meters or more on quality coaxial cable. HD-SDI extends to about 200 meters. 3G-SDI reaches about 100 meters. 6G-SDI goes about 70 meters. 12G-SDI goes about 50 meters. Beyond these limits, use an SDI-over-fiber extender that converts the signal for transport over fiber optic cable (often several kilometers), or chain multiple re-clocking SDI distribution amplifiers as regeneration points. The lower the SDI rate, the more cable margin you have, which is one reason older broadcast facilities can still run HD-SDI on existing cable plant that was designed for SD.

Yes. SDI embeds up to 16 channels of audio along with the video signal, plus timecode and ancillary data. One of the strengths of SDI is that everything travels in a single coax run: video, multi-channel audio, timecode for sync, closed-caption data, and other metadata. An SDI distribution amplifier passes all of this transparently to every output, so each downstream device receives the full bundle without external audio routing or sync infrastructure. This makes facility design much simpler than with HDMI or DVI, where audio must be planned separately.

Broadcast OB trucks, live sports production, news studios, live worship production, post-production, and control rooms are the most common environments. Any production where cameras, recorders, switchers, and monitors all need a clean copy of the same feed is a candidate. Specific examples include sending the main program output to multiple recorders for redundant capture, distributing a single camera feed to several preview monitors in a control room, feeding the broadcast truck's program output to multiple downstream encoders and contribution lines, or driving a confidence-monitor wall that lets the director and producers see every camera and graphics source at once.