files/en-us/web/api/pannernode/positionx/index.md
{{ APIRef("Web Audio API") }}
The positionX property of the {{ domxref("PannerNode")}} interface specifies the X coordinate of the audio source's position in 3D Cartesian
coordinates, corresponding to the horizontal axis (left-right).
The complete vector is defined by the position of the audio source, given as
(positionX, {{domxref("PannerNode.positionY", "positionY")}},
{{domxref("PannerNode.positionZ", "positionZ")}}), and the orientation
of the audio source (that is, the direction in which it's facing), given as
({{domxref("PannerNode.orientationX", "orientationX")}},
{{domxref("PannerNode.orientationY", "orientationY")}},
{{domxref("PannerNode.orientationZ", "orientationZ")}}).
Depending on the directionality of the sound (as specified using the attributes {{domxref("PannerNode.coneInnerAngle", "coneInnerAngle")}}, {{domxref("PannerNode.coneOuterAngle", "coneOuterAngle")}}, and {{domxref("PannerNode.coneOuterGain", "codeOuterGain")}}), the orientation of the sound may alter the perceived volume of the sound as it's being played. If the sound is pointing toward the listener, it will be louder than if the sound is pointed away from the listener.
The {{domxref("AudioParam")}} contained by this property is read only; however, you can still change the value of the parameter by assigning a new value to its {{domxref("AudioParam.value")}} property.
An {{domxref("AudioParam")}} whose value is the X coordinate of the audio
source's position, in 3D Cartesian coordinates. The default value is 0.
The following example starts an oscillator, and pans it to the left after 1 second, to the right after 2 seconds, and back to the center after 3 seconds.
const context = new AudioContext();
const osc = new OscillatorNode(context);
const panner = new PannerNode(context);
panner.positionX.setValueAtTime(-1, context.currentTime + 1);
panner.positionX.setValueAtTime(1, context.currentTime + 2);
panner.positionX.setValueAtTime(0, context.currentTime + 3);
osc.connect(panner).connect(context.destination);
osc.start(0);
{{Specifications}}
{{Compat}}