Why is there an audio driver with your computer’s graphics chipset?

The HDMI and DisplayPort outputs make use of the display audio device driver for sound they send to the external display

Some of you may take stock of what device drivers and software exist on your Windows computer and may find two or more audio device drivers on your computer with one being referred to as an “HDMI” or “Display” audio driver. Such a driver will have a reference to the graphics chipsets that are installed in your computer. Why does this driver exist and how could I take advantage of this setup?

The standard audio setup

Most computers are nowadays equipped with an on-board audio infrastructure of some sort. This was initially a sound card but is nowadays an on-board audio chipset like Realtek or Intel HD Audio. Here, it would have its own digital-analogue audio circuitry and would be serving integrated speakers or audio equipment like computer speakers that are connected to the computer’s own audio jacks.

The better implementations would have an SP/DIF audio output which would serve an outboard digital-analogue converter or digital amplifier. In this case, the audio infrastructure would repackage the sound in to an SP/DIF-compliant form either as a PCM stream or a bitstream supporting Dolby Digital.

In this case, the above-mentioned sound infrastructure would work with its own driver software and be listed as a distinct audio device in Windows. With most of the recent laptops that have sound tuning provided typically by a name-of-respect in the professional-audio or hi-fi scene, this driver also has the software component that is part of this tuning.

HDMI and DisplayPort adds a point of confusion

Windows Sound Control Panel

HDMI output for monitor as a unique audio playback device in Windows

HDMI and DisplayPort display connections have the ability to transport a digital audio stream along with the video stream over the same cable. Therefore, display-chipset and graphics card manufacturers have had to support digital-audio transport for host-computer audio through these connections.

In some early setups, it required that the computer’s sound card or audio chipset expose a digital-audio stream via the HDMI or DisplayPort connection. With graphics cards, this typically required a wired connection between an SP/DIF digital output on a sound card or motherboard audio chipset and a digital input on the graphics card.

But recent implementations used a cost-effective digital-audio processor as part of the graphics infrastructure which simply repackages the digital audio stream from the host computer to a form that can be handled by the display or audio device connected via the HDMI or DisplayPort connection. During the initial setup of an HDMI or DisplayPort connection, it will be about determining what audio codecs, bit-depths and sampling frequencies the connected monitor, TV, home-theatre receiver or other audio-equipped device can handle.

Sony STR-DN1060 home theatre receiver press picture courtesy of Sony America

If you connect your computer to your monitor or TV even via the HDMI connections on one of these home-theatre receivers, you will be using the HDMI audio subsystem and display audio driver as outlined here

This also applies to computers and display setups that use the USB-C port as a “DisplayPort alt” connection like some of the laptops that have come my way for product review. But if you are using a USB-C expansion module that has audio connections, you may find that this device may use a USB-based sound chipset to serve those connections. Typically this chipset will use the USB Audio Device class drivers that are part of the operating system rather than the “display audio” drivers.

If you connect your computer to your display via an HDMI audio device like a home-theatre receiver, soundbar or HDMI audio adaptor, you will find that the audio device will be identified as the sound-output device for the “display audio” device.

In this case, you would see another audio device listed in your computer’s audio device list with a name that references your computer’s graphics chipset like Intel Display Audio or AMD HDMI Audio. The only audio-endpoint device that these drivers refer to are whatever audio device is connected to your computer’s HDMI or DisplayPort connection.

What do I do about the existence of these “display audio” drivers?

If you are trying to rationalise the driver software that exists on your computer, don’t remove the “display audio” or “HDMI audio” drivers associated with your computer’s graphics infrastructure. This is because if you connect a TV, monitor with speakers or home-theatre audio device to your computer via the HDMI or DisplayPort connections and you remove the “display audio” driver, the sound won’t play through devices connected via those connections.

Instead, keep these “display audio” drivers up-to-date as part of updating your computer’s graphics-infrastructure software. Here, it will preserve best compatibility for the communications, games and multimedia software and Websites you run on your computer if you are using audio-capable devices connected via HDMI or DisplayPort along with this audio-capable hardware hanging off these ports.

Also remember that if you are using an audio-capable display device connected via the HDMI or DisplayPort connections, you need to use the “diisplay audio” driver to hear your computer’s or application’s sound through that device. This may require you to have it as a “default sound playback device” for software that doesn’t support audio-device switching like Spotify or Web browsers.

Computer systems with multiple graphics chipsets

Computer systems that implement multiple graphics chipsets may also run multiple “display audio” drivers for each chipset. Here, the audio to be sent via the HDMI or DisplayPort output would be processed by the “display audio” chipset for the currently-used chipset.

Some setups may require you to manually select the “display audio” chipset that you are using when you are directing the sound via your audio-equipped display device. This may especially apply to the use of external graphics modules.

But on the other hand, a multiple-graphics-chipset computer may implement a virtual “display audio” or “HDMI audio” driver that automatically steers sound output to the HDMI or DisplayPort device via the currently-used graphics chipset without you needing to intervene. This kind of driver will be relevant with computers that implement NVIDIA Optimus or similar logic to automatically select the appropriate chipset depending on whether you are after high graphics performance or longer battery runtime.

A solution for “steering” Windows sound output towards the devices you want

You can steer particular applications’ sound through your laptop’s HDMI output using the display audio driver

When I installed the Windows 10 April Update (Build 1803) on my computer, I had found the improved sound-management ability that this operating system update offers can make better use of this arrangement. I chose to create a sound setup to steer multimedia to better sound outputs while keeping the audio prompts that Windows makes during errors towards a lower-quality output and documented how this is done.

Here, the “display audio” driver will earn its keep as a way to allow the speakers in your smart TV, home-theatre setup or audio-equipped monitor connected to your computer’s HDIMO or DisplayPort output to be used only by the software that you want.

There are two situations that this will encompass. One is to have a laptop connected to the large TV or home-theatre setup for some Netflix binge-watching but you rather have Windows sound its notification sounds through the laptop’s own small speakers.

The other is where you use a monitor with not-so-great speakers as your primary display but want music or other multimedia to come out through a better sound system connected to your computer. It also includes desktop computers used in an AV playout role with a projector and PA system conveying the audio-video content to the audience but using a monitor with not-so-great speakers as the operator’s display.

The first situation involving a laptop would have the standard audio driver serving the integrated speakers set up as a “default” sound device while the Web browser or multimedia software uses the display-audio driver as the output device. The second situation using a monitor with not-so-great speakers would have the display-audio driver as the default driver while the Web browser or multimedia software handling the AV content to be played to the audience uses the audio driver associated with the better sound system.

Conclusion

Simply, the “display audio” or “HDMI audio” driver works with your computer’s graphics infrastructure as a separate audio driver to present sound from your computer to an audio-capable monitor or A/V device connected via its DisplayPort or HDMI connections.

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