# Center channel used randomly

**URL:** <https://qa.fmod.com/t/center-channel-used-randomly/11573>\
**Category:** FMOD Studio\
**Created:** [July 24, 2014, 8:45am UTC](https://qa.fmod.com/t/center-channel-used-randomly/11573 "2014-07-24T08:45:39Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![flolaq](https://avatars.discourse-cdn.com/v4/letter/f/90ced4/32.png) [@flolaq](https://qa.fmod.com/u/flolaq)\
**Post date:** [July 24, 2014, 8:45am UTC](https://qa.fmod.com/t/center-channel-used-randomly/11573/1 "2014-07-24T08:45:39Z")

</div>

I use a 4 channel - wav file in a Studio event which is distributed correctly to the two front and the two surround speaker channels (channels 0, 1, 4, 5). In order to have an output on the subwoofer (channel 3) I created a Mix Matrix that takes 25% of each input channel and routes it to the subwoofer channel.

However it happens randomly (NO changes in the code) that the center speaker also shows a signal and sometimes not. Setting the respective entries with setMixMatrix to 0.0f for the center (channel 2) has no effect.

My System:

Windows 7 32 bit  
FMOD Studio API 1.04.04  
ASIO driver  
Sound Interface: Focusrite Scarlett 18i20

Thanks for your help in advance!

Florian

---

<div class="post-metadata">

**Author:** ![flolaq](https://avatars.discourse-cdn.com/v4/letter/f/90ced4/32.png) [@flolaq](https://qa.fmod.com/u/flolaq)\
**Post date:** [July 24, 2014, 11:49am UTC](https://qa.fmod.com/t/center-channel-used-randomly/11573/2 "2014-07-24T11:49:56Z")

</div>

> [@](#):
>
> I use a 4 channel - wav file in a Studio event which is distributed correctly to the two front and the two surround speaker channels (channels 0, 1, 4, 5). In order to have an output on the subwoofer (channel 3) I created a Mix Matrix that takes 25% of each input channel and routes it to the subwoofer channel.
> 
> However it happens randomly (NO changes in the code) that the center speaker also shows a signal and sometimes not. Setting the respective entries with setMixMatrix to 0.0f for the center (channel 2) has no effect.
> 
> My System:
> 
> Windows 7 32 bit  
> FMOD Studio API 1.04.04  
> ASIO driver  
> Sound Interface: Focusrite Scarlett 18i20
> 
> Thanks for your help in advance!
> 
> Florian

Update:

When I disable the center speaker in Studio, there is never an output on the center speaker.

HOWEVER: It happens randomly that the front channels have higher volume, the surround ones lower volume as if the center channel was correctly disabled. But it also happens that the volumes stay the same just as if the channel was still used, but no signal is getting to it.

All this only happens when my application is started over, during runtime the behavior stays the same!

---

<div class="post-metadata">

**Author:** ![flolaq](https://avatars.discourse-cdn.com/v4/letter/f/90ced4/32.png) [@flolaq](https://qa.fmod.com/u/flolaq)\
**Post date:** [July 25, 2014, 9:02am UTC](https://qa.fmod.com/t/center-channel-used-randomly/11573/3 "2014-07-25T09:02:23Z")

</div>

Update: When I play an event with 3 channels (3 channel wav file used in a Studio event) the channels get assigned to front left / right and center. The center channel fades to zero after some parameter updates but stays the same if no parameters are changed. This does NOT happen to the front left/right channels so something must be wrong with the center channel as they are treated exactly the same.