SmartAVI HDN-4 DUO - 4-Port, Dual-Head HDMI (4K/30Hz) Ultra-HD KVM switch w/ USB 2.0 and Audio



Replaced by: SmartAVI SM-UHN-4D-S
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Model: Dual Monitor

The SmartAVI HDN-4DUO is a dedicated multi-platform KVM switch capable of managing up to 4 different computers through two HDMI monitors, one USB keyboard & mouse, a single set of speakers and a USB 2.0 Device.

The USB emulation technology utilized by HDN-4DUO enables immediate hotkey source switching through a remote USB keyboard and mouse. HDN-4DUO uses single link connectors providing high resolutions of up to 4K (3840x2160 @ 30Hz) with zero pixel loss from TMDS signal correction.

SmartAVI HDN-4DUO Rear

  • 4-port KVM switching; access & control keyboard-video-mouse functions on up to 4 remote computers
  • Supports Ultra-HD 4K (3840x2160 @ 30Hz) - 4K-ready HDMI 2.0 connectors
  • Zero pixel loss with TMDS signal correction
  • Supports all USB 2.0 Devices (keyboard, mouse, peripherals).
  • 2x USB Peripheral Ports - Independent (asynchronous) switching of KVM and peripheral USB ports.
  • Balanced stereo audio output - independent switching. Users can listen to audio from one computer while working on the other or scan a document and save in another computer.
  • Front panel keys for selecting users and channels manually
  • RS-232 control for remote control
  • Hot-key commands for quick channel selection.
  • Complete keyboard emulation for error free booting
  • Control Sun, Mac, Linux, Unix or PC computers from a common KVM console
  • Rack mountable in a standard 19 inch rack (rackmount kit sold separately)

SmartAVI HDN-4DUO Application

Controlling the HDN-4DUO

The HDN-4Quad is plug-and-play, easy to install into any AV setup and use right out of the box! Once set up, the HDN-4DUO is controlled with:

  • Front Panel Push Buttons: The HDN-4 DUO comes equipped with clearly marked push buttons on its front-panel, putting KVM control literally within your reach
  • USB Keyboard Hotkey Commands: Simple hotkey commands over PC that offer more robust control of the HDN-4DUO.
  • RS-232: Use an external device with RS-232 capabilities to control the HDN-4 DUO- our easy device integration makes it a breeze to connect the KVM unit to RS-232 ready devices.

Display Data (EDID) Learning & Programming

Detection of DDC signals for all attached devices is effortless with HDN-4Duo due to its real EDID learning and programming. This is vital in optimizing the resolution of the selected graphics card to properly display on the remote monitor. Furthermore, the EDID learning feature continues to replicate the right DDC for the computer to enable the display card to effectively work when unused ports are not selected.

Full USB Keyboard & Mouse Emulation

The USB keyboard and mouse emulation utilized by HDN-4Duo provides accurate and quick source switching by means of keyboard hotkeys and mouse actions. HDN-4Duo imitates the presence of a keyboard and mouse for every attached computer through a USB cable. This is essential as it simulates the existence of the keyboard and mouse to all the computers while switching without interruptions.


  • (1) HDN-4Duo
  • (1) Power supply
  • (1) Quick Start Guide

SmartAVI HDN-4DuoS Specifications:

FormatHDMI 1.4
Input Interface(8) HDMI
Output Interface(4) HDMI
ResolutionUp to 4K UHD (3840x2160 @ 30Hz)
DDC5 volts p-p (TTL)
Input EqualizationAutomatic
Input Cable LengthUp to 20 ft.
Output Cable LengthUp to 20 ft.
Input Interface(4) 3.5 mm Stereo Audio
Output Interface(1) 3.5 mm Stereo Audio
Impedance600 Ohm
Frequency Response20 Hz to 20 kHz
Nominal Level0-1.0 V
Common ModeRejection at 60 dB
Signal TypeUSB 2.0, 1.1, and 1.0 w/ internal hub
Input Interface(4) USB Type B (female)
Output Interface(2) USB 1.1 Type A (female) for keyboardand mouse
(2) USB 2.0 Type A Transparent
Front Panel Buttons< M1||M2 > source selection buttons
RS-232DB9 Female - 9600 N,8,1, No flow control
Hot Keysvia USB keyboard
PowerExternal 100-240 VAC/ 5VDC4A @ 20W
Dimensions12.5" W x 4.3" H x 6.4" D
Weight3.95 lbs.
ApprovalsUL, CE, ROHS Compliant
Operating Temp.23-95 °F (-5-35 °C)
Storage Temp.-4-185 °F (-20-85 °C)
HumidityUp to 95%
EmulationKeyboard and Mouse; EDID information from display
Question: I can not get the hotkeys to work?
Answer: Thank you for your inquiry,

We are sorry to hear of the issue you are experiencing!

To activate the hotkey sequence, press the CTRL key twice and then enter the desired hotkey commands. Hotkey commands are listed one page 6 of the SmartAVI HDN-4-DUO Manual.

If you continue to experience issue with Hot Key Switching, please feel free to reach out to SmartAVI Technical Support team at or (800) 284-2131, who can assist with walking through your environment to troubleshoot.

Please let us know if there is anything else we can ever help you with!