StarTech ST122HDMI2 2-Port HDMI Splitter with Audio Output

Overview

The StarTech ST122HDMI2 is a one-input, two-output HDMI splitter that mirrors a single HDMI source — video and audio — to two displays simultaneously. It supports resolutions up to 1920x1200 (PC) and 1080p (HDTV), making it a practical fit for digital signage loops, dual-monitor briefing rooms, control rooms running a shared source, or any AV installation where one signal needs to reach two screens without a receiver or software workaround. The steel chassis and external power supply design keep the unit stable under continuous operation, unlike bus-powered alternatives that can drop signal under load.

This is not a switching device — it does not select between inputs. One source goes in, both outputs carry the identical signal. If your project requires switching between multiple sources, you need a different product class entirely. For pure signal distribution from one source to two destinations, the ST122HDMI2 covers the requirement cleanly.

Explore the full StarTech connectivity catalog for complementary switching, extension, and conversion products.

Key Features

• Dual HDMI Outputs at 1080p / 1920x1200: Both outputs carry the full signal simultaneously — no resolution penalty on either screen. 1920x1200 support means it handles WUXGA computer monitors without downscaling, which matters in command centers or engineering workstations feeding secondary displays.
• Integrated 3.5mm Audio Distribution: One 3.5mm audio input splits to two 3.5mm audio outputs alongside the HDMI video. If your source device outputs audio separately (common with older PCs or switchers), you can run both video and audio to two sets of powered speakers or amplifiers without an additional audio splitter in the chain.
• Up to 15m (49.2 ft) Output Cable Runs: The built-in signal amplifier compensates for cable loss, supporting output cable runs up to 15 meters. That gives you enough reach to span a standard conference room, lobby, or open-plan office without signal degradation — no inline amplifier needed at the display end.
• Three LED Status Indicators: On-board LEDs confirm power and signal status at a glance. During installation or troubleshooting, you can verify which outputs are active without pulling out test equipment — a small detail that speeds up commissioning in rack or wall-mount deployments.
• Steel Enclosure for Continuous-Duty Use: The all-steel chassis handles the heat dissipation demands of 24/7 operation better than plastic-body alternatives. At 13W consumption with a 12V DC / 1.5A external supply, thermal load is modest, but the steel body keeps operating temperatures in check within the 0°C–40°C rated range.
• Universal AC Input (100–240V): The included power supply accepts any mains voltage from 100 to 240V AC at 0.6A, so the same unit deploys in North America, Europe, or Asia without a step-down transformer. Useful for global enterprise deployments or resellers stocking a single SKU.
• Compact Form Factor: At 7.1 × 3.1 × 0.8 in (18 × 8 × 2 cm) and 13.4 oz (380g), the ST122HDMI2 sits flat behind a display, on a shelf, or in a rack drawer without consuming dedicated rack space. The low-profile design is especially practical in podium or lectern AV installs where space is constrained.

Integration and Compatibility

The ST122HDMI2 works with any HDMI-compliant source — Blu-ray players, media PCs, set-top boxes, presentation systems, or digital signage players — and any HDMI-compliant display. There are no driver installations or software dependencies; the device is plug-and-play at the hardware level.

For HDMI cable runs approaching the 15m rated limit, use high-quality 28AWG or thicker HDMI cables rated for the distance. Passive cables beyond 10m can introduce signal instability that the splitter's amplifier may not fully compensate for — factor this into your cable specification if you're running near the maximum. If your installation requires runs beyond 15m, consider pairing this splitter with an HDMI extender on the output side.

The 3.5mm audio loop is passive distribution — it does not provide amplification. Downstream devices (speakers, amplifiers) must supply their own power. This splitter is designed for AV signal distribution in fixed installations; it is not engineered for live production or broadcast environments where signal integrity tolerances are more demanding.

Operating humidity ceiling of 80% RH (non-condensing) and a 0°C–40°C operating range cover standard indoor commercial environments. It is not rated for outdoor or industrial enclosure use.

Frequently Asked Questions

Q: Does the ST122HDMI2 support 4K resolution?

A: No. The ST122HDMI2 is rated to a maximum of 1080p (HDTV) and 1920x1200 (PC). It does not support 4K (3840x2160) or UHD resolutions. If you need 4K distribution, you will need a different model.

Q: Can the ST122HDMI2 switch between two HDMI sources and send to one display?

A: No. This unit is a splitter, not a switch. It takes one HDMI input and distributes it to two HDMI outputs simultaneously. For source switching, a separate HDMI switch or matrix is required.

Q: What is the maximum output cable length supported?

A: The ST122HDMI2 supports output cable runs up to 15 meters (49.2 feet) thanks to its built-in signal amplifier. Cable quality affects achievable distance — use high-quality cables, especially near the upper limit.

Q: Does the audio output on the ST122HDMI2 provide amplification?

A: No. The two 3.5mm audio outputs distribute the signal from the single 3.5mm audio input but do not amplify it. Connected speakers or audio systems must be self-powered.

Q: What is the warranty on the ST122HDMI2?

A: The ST122HDMI2 carries a 2-year manufacturer warranty.

Q: Will the ST122HDMI2 work on international mains power without an adapter?

A: Yes. The included power supply accepts 100–240V AC input, covering North American, European, and Asian mains voltages. Only the wall plug shape may differ — a plug adapter (not a voltage converter) may be needed depending on the country.

Jerry Tildsen

The ST122HDMI2 is the kind of unit I reach for when the ask is straightforward: one source, two screens, audio included, nothing exotic. The built-in signal amplifier supporting 15-meter output runs is the detail that separates it from passive splitters — passive units start losing signal integrity past 5–7 meters, which is exactly where most real-world installs actually run cable.

Technical Highlights:

• Signal Amplification to 15m: Active amplification on both output legs supports cable runs up to 49.2 ft — practical for lobby signage, dual-screen presentation rooms, and control stations where the display isn't sitting next to the source rack.
• 1920x1200 PC Resolution Support: WUXGA coverage means this unit handles high-resolution PC monitors without downscaling to 1080p — important in operations centers or engineering workstations feeding a secondary reference display.
• 100–240V Universal Input: The external PSU handles any global mains voltage, which simplifies procurement for multi-region projects — same SKU ships to any site without voltage conversion hardware.

Deployment Considerations:

• Operating temperature ceiling is 40°C — confirm the installation environment (AV rack, podium cabinet, ceiling void) doesn't exceed that under sustained load, particularly in summer or in poorly ventilated enclosures.
• The 3.5mm audio outputs carry signal only — no amplification. If the downstream displays or speakers don't have their own amplifier stage, you'll need active speakers or a separate audio amp in the chain; a passive connection to unpowered speakers will produce no audible output.

Best fit for fixed installations running a single high-definition source to two displays: hotel lobby digital signage pairs, dual-screen briefing room setups, or security operations centers distributing a shared video wall source to a supervisor monitor and a main screen — anywhere the routing is static and the cable runs are under 15 meters.