Make sure your project is configured to output stereo audio. You can access the audio output setting in your Unity editor from Edit > Project Settings > Audio.

Implementation

The following are the general steps you might take to add a new mono sound event to your project and setup the Meta XR Audio SDK to spatialize it.

Create a new event. In FMOD Studio, go to Events, and select New Event or New 3D Event, depending on what version of FMOD you are using.

Find and select the event’s master track.

Sending an event to the master track in FMOD Studio.

If there is a 3D Panner effect loaded on the channel by default, select and delete the 3D Panner. This is done because using both the FMOD default spatializer and the Meta plugin will result in the source being spatialized twice and it will not sound correct.

Removing the default FMOD spatializer from the event.

Add the MetaXRAudio Source plugin. In the event deck, open the context menu and choose Add Effect > Plug-in Effects > Meta > MetaXRAudio Source.

Selecting the Meta XR Audio plugin from the FMOD Studio context menu.

The plugin should appear in the DSP chain as shown below:

FMOD event with the Meta XR Audio Source instance added.

Set the master track input format to mono by right-clicking on the metering bars on the left side and choosing Mono.

Setting the master track input format in FMOD Studio.

Repeat these steps for each Event you’d like to spatialize in your FMOD project.

Learn More

Below are the specific technical details of every control available on the UI of the Meta XR Audio Source plugin.

Source settings

The following table lists and describes settings for the spatializer.

Setting	Description
Enable Acoustics	Set to On to enable reflections calculations. Reflections take up extra CPU, so disabling can be a good way to reduce the overall audio CPU cost. Reflections will only be applied if the Reflection Engine is enabled on the Meta XR Reflections effect. For more information, see Attenuation and Reflections section of the Audio Guide.
Reverb Send dB	Controls a gain applied to the event’s audio prior to rendering it’s late reverberation. The direct sound of the audio is untouched. Values are in dB and more positive values lead to louder sends to the reverb bus which make the object more prevalent in the late field reverberation (which could swamp the direct sound if your not careful).
Distance Attenuation	Set to one of the four built in distance attenuation curves to enable the internal distance attenuation model. If attenuation is disabled by choosing Off, you can create a custom attenuation curve using a volume automation on a distance parameter.

Experimental source settings

The following table lists the describes the experimental features for the Meta XR Audio source. These parameters are subject to change or removal in future versions of the SDK.

Setting	Description
Directivity Pattern	If set to 1 or Human Voice, then audio object’s radiation pattern will mimic that of the human voice meaning when the object is faceing away from the listener, it is attenuated (and low-pass filtered) and unaltered when directly facing the listener. A setting of 0 or None means the audio object will be rendered as an omnidirectional radiator and its orientation relative to the listener will not affect how the object is rendered at all.
Early Reflections Send dB	Controls a gain applied to the objects audio prior to rendering it’s early reflections. The direct sound of the audio is untouched. Values are in dB and more positive values lead to louder early reflections (which could swamp the direct sound if your not careful).
Volumetric Radius	Specifies the radius to be associated with the sound source, if you want the sound to seem to emanate from a volume of space, rather than from a point source. Sound sources can be given a radius which will make them sound volumetric. This will spread the sound out, so that as the source approaches the listener, and then completely envelops the listener, the sound will be spread out over a volume of space. This is especially useful for larger objects, which will otherwise sound very small when they are close to the listener. For more information, see these blog articles.
HRTF Intensity	When set to zero, the HRTFs used to render high-quality voices are essentially simplified to a stereo pan (with ITD still applied). When set to one, the full HRTF filter is convolved. Any setting other than 1 will reduce the timbral shifts introduced by the HRTF at the expense of poorer localization.
Directivity Intensity	When set to 1, the full directivity pattern will be applied. As the value reduces towards zero, the directivity pattern will be blended with an omnidirectional pattern to reduce the intensity of the effect.
Reverb Reach	This parameter adjusts how much the direct-to-reverberant ratio increases with distance. A value of 0 causes reverb to attenuate with the direct sound (constant direct-to-reverberant ratio). A value of 1 increases reverb level linearly with distance from the source, to counteract direct sound attenuation.
Occlusion Intensity	This parameter adjusts the strength of the occlusion when the source is not directly visible. This parameter only applies when using the Acoustic Ray Tracing feature. A value of 1 means full effect (realistic occlusion), while 0 means no occlusion occurs.
Medium Absorption	When enabled, the audio source will apply frequency specific attenuation over distance as a result of the medium the sound travels through (air for example). Note this control only applies when Acoustic Ray Tracing is active and has no effect for Shoebox Reverb.
Direct Enabled	When disabled, the source will still be sent to the internal reverb send but the direct output of this audio source will be silenced.