# Is there a way to get left/right speaker volume after specializing the sound?

**URL:** <https://qa.fmod.com/t/is-there-a-way-to-get-left-right-speaker-volume-after-specializing-the-sound/20069>\
**Category:** FMOD Engine\
**Created:** [April 4, 2023, 11:54pm UTC](https://qa.fmod.com/t/is-there-a-way-to-get-left-right-speaker-volume-after-specializing-the-sound/20069 "2023-04-04T23:54:43Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![chrane](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@chrane](https://qa.fmod.com/u/chrane)\
**Post date:** [April 4, 2023, 11:54pm UTC](https://qa.fmod.com/t/is-there-a-way-to-get-left-right-speaker-volume-after-specializing-the-sound/20069/1 "2023-04-04T23:54:44Z")

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Say the listener is to the left of a sound source, the right speaker should have a higher volume than left.

I tired get metering info, but perhaps because the sound source is a mono file it only has one channel for the rms reading. Out of the 32 channels, only the first channel has reading.

I also tried using getMixMatrix but couldn’t seem to get it working. If this is the right path, is there an example I can refer to?

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<div class="post-metadata">

**Author:** ![chrane](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@chrane](https://qa.fmod.com/u/chrane)\
**Post date:** [April 5, 2023, 1:11am UTC](https://qa.fmod.com/t/is-there-a-way-to-get-left-right-speaker-volume-after-specializing-the-sound/20069/2 "2023-04-05T01:11:46Z")

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NVM I was targeting the wrong DSP, got it working through getMeterInfo. Still curious how getMixMatrix works though.

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**Author:** ![Leah\_FMOD](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/leah_fmod/32/3685_2.png) [@Leah\_FMOD](https://qa.fmod.com/u/Leah_FMOD)\
**Post date:** [April 5, 2023, 2:40am UTC](https://qa.fmod.com/t/is-there-a-way-to-get-left-right-speaker-volume-after-specializing-the-sound/20069/3 "2023-04-05T02:40:38Z")

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The mix matrix is a 2D array of floats used by `ChannelControl` and `DSPConnection` to map input channels (columns) to output channels (rows) - it isn’t related to metering.

By default, the mix matrix should be an [identity/unit matrix](https://en.wikipedia.org/wiki/Identity_matrix) that maps a given input channel only to its corresponding output channel:

```auto
// Quadraphonic -> Quadraphonic Identity Matrix
               Inputs
             ___________
             FL FR RL RR
        | FL 1 0 0 0
        | FR 0 1 0 0
Outputs | RL 0 0 1 0
        | RR 0 0 0 1

```

but you can use it to arbitrarily route any combination of input channels to any output channel. For example, you could use it to:

- Remove the right channel from a stereo signal

```auto
// Stereo -> Stereo Mix Matrix
  L R
L 1 0
R 0 0

```

- Route all 6 channels of a 5.1 signal solely to the Centre channel

```auto
// 6.1 -> 6.1 mix matrix
    FL FR C LFE SL SR
FL 0 0 0 0 0 0
FR 0 0 0 0 0 0
C 1 1 1 1 1 1
LFE 0 0 0 0 0 0
SL 0 0 0 0 0 0
SR 0 0 0 0 0 0

```

and so on. You can attenuate the signal of a given mapping by specifying a value between 0 and 1, amplify it with a value above 1, and/or additionally invert the signal by using a value below 0. Mix matrices also allow you to downmix from a lower amount of input channels to a higher amount of output channels, or upmix with the inverse opposite.

I’d recommend reading the [`ChannelControl::getMixMatrix`](https://www.fmod.com/docs/2.02/api/core-api-channelcontrol.html#channelcontrol_getmixmatrix) and [`ChannelControl::setMixMatrix`](https://www.fmod.com/docs/2.02/api/core-api-channelcontrol.html#channelcontrol_setmixmatrix) documentation for more information.