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What Does Mean on a Soundbar?

If you’re looking at your soundbar, you might see a label on one of the inputs on the back. You may have even seen it on other media devices, too. If you’re wondering what it means and what it does, you’re in the right place, because we have many tutorials on what all of these things mean, in fact, we have another guide on how to set up a soundbar without a TV using the other available input options, assuming your soundbar has them.

What does mean on a soundbar? On a soundbar,, D-In, or Digital In all mean digital input. A digital input is also called a digital optical input, and it is used to send a digital audio signal from the source to the speaker over fiber optic cable.

A digital input, however it is labeled on your soundbar, requires a digital optical cable to make the optical audio connection. This type of input is different from HDMI or HDMI-ARC inputs, as well as coaxial inputs, and it has different capabilities.

Capabilities of the Digital Input on a Soundbar

Digital Optical Cable on a Desk

The digital input is an input option on a soundbar, which is usually located on the back. Most soundbars will have a digital input, and you will want to use a digital optical cable like the BlueRigger Digital Optical Audio Cable (on Amazon) when making the connection between your soundbar and component.

On a soundbar, the digital input’s main job is to transfer the digital audio signal from any component to your soundbar, including your TV, video game console, smart home device, speakers, etc. This way, you can hear the audio through your soundbar from your TV, games, music, etc.

And the naming convention around this port can definitely be confusing. When it comes to cables and ports, it’s not strange to see terms like Digital Optical, Toslink, and SPDIF all used interchangeably.

However, these cables always have the characteristic square-ish connector which clicks into place. But be careful: that fiber-optic cable inside means you can actually snap a cable if you try to bend it too much, making these a little fragile.

Digital Input vs. HDMI: Differences in Quality

HDMI Cable and Digital Optical Cable on a wooden desk

It used to be that coaxial cables like this typical RG6 Coax Cable (on Amazon) were all you needed for connecting audio and video between devices. These days, you may have to choose between the or digital input and the HDMI input.

While Coax and HDMI carry both the audio and video signal, either one of them might be used “upstream” of the soundbar to get content on your screen. Then, an optical cable can be used in parallel to connect the audio source to the soundbar.

Since both digital input and HDMI function to transfer audio content from one device to another device, you might be wondering which is better to use. One of the most significant differences between the digital optical input and HDMI cables is that an HDMI cable passes high-resolution audio, as well as video.

Sso you may want to connect your soundbar via HDMI, especially if your screen and soundbar have HDMI-ARC built-in (more on that in our article here).

Some of the major differences in digital optical and HDMI are:


HDMI supports DTS HD, TrueHD formats, and Dolby Digital Plus. At the same time, digital input supports only the surround system with up to 5.0 channels. Most television programming only uses surround sound to broadcast, but you may be missing these added formats with Blu-Ray discs and other higher-level media.

This may be a limitation for some. If you consider a soundbar like the Nakamichi Shockwafe Ultra, which we’ve reviewed on the site before, you’ll know that the soundbar itself supports a 9.2.4 surround system, so connecting an optical cable to it would limit the functionality significantly.


As discussed briefly above, a digital optical cable uses fiber optic technology. A glass fiber at the core of the table transmits light signals which are much less vulnerable to interference when compared to copper wires. HDMI doesn’t use this technology, but for short runs of cable, the quality difference isn’t super substantial unless you are a dedicated audiophile.


HDMI cables transmit both video and audio, reducing the need to have another cable. The cost of the two cables that are required for utilizing the digital input and another input for video may be more expensive than just purchasing one HDMI cable.


The length may not be so crucial for every user, but you might end up losing quality signal over the length of the cables. So, when selecting between HDMI and digital input, you may consider simply choosing the shortest one.

What About the Coaxial Connection?

Gold-pated Digital COAX audio cable

This type of connection was initially used to transmit telephone and radio signals. The coaxial connection cable is made up of a copper core. Coaxial connection cable carries a signal from the television to the programmed source. 

This type of connection is identified by the characteristic single-pin connector that is screwed into a matching hole for a secure connection. Coaxial cables provide a wider bandwidth per channel, which is why some Telecomm companies use them for near-gigabit speed internet.

Devices that have Digital Input Connections

 Digital input options are typically included on new hardware in the following categories:

  • TVs
  • DVD players
  • Video game consoles
  • Media streamers
  • Home theater receivers
  • Media streamers
  • Blu-Ray players
  • DVRs
  • Select stereo receivers
  • Satellite/cable boxes
  • Select CD players
  • Soundbars

But be sure to check your equipment to make sure ahead of time that you have the ports you need. A Sonos Arc Soundbar, for instance, is very expensive but doesn’t have an optical port, so it isn’t always included by default.

How to Connect Your Soundbar to your TV using the Digital Input

Connecting your soundbar to a television using the digital input is very simple — it doesn’t demand any technological knowledge. Most soundbar systems provide detailed guidelines on how to connect it to your television, so check the instruction manual for more assistance.

  1. You’ll need a working digital optical cable to get started.
  2. Once you have the digital optical cable ready, check your television for a port marked as digital audio out. This port transfers the digital audio signal, which will be used to pass to the soundbar or another compatible device. Look for that characteristic square-ish connector.
  3. Plug both sides of the cable to the digital audio port of your soundbar — the ‘Optical In’ and on the television, the ‘Optical Out’.
  4. Power on your devices.
  5. Set your soundbar to digital input using the source button on your remote. The display will likely show D-IN on the front of the panel of the soundbar.
  6. If no audio was established after the above connection, check your TV audio system. You may need to turn off the TV’s native speakers in the settings and direct it to the soundbar through the digital input.