# FMOD 2.0 get spectrum data of Event Instance

**URL:** <https://qa.fmod.com/t/fmod-2-0-get-spectrum-data-of-event-instance/14499>\
**Category:** Unity\
**Created:** [March 29, 2019, 3:32pm UTC](https://qa.fmod.com/t/fmod-2-0-get-spectrum-data-of-event-instance/14499 "2019-03-29T15:32:56Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Wagi](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/wagi/32/231_2.png) [@Wagi](https://qa.fmod.com/u/Wagi)\
**Post date:** [March 29, 2019, 3:32pm UTC](https://qa.fmod.com/t/fmod-2-0-get-spectrum-data-of-event-instance/14499/1 "2019-03-29T15:32:56Z")

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Hello here,

I’m a newbie in fmod integration and I’m maybe asking something obvious.

As I’m trying to build a sound responsive post process, I need to get some Spectrum data.  
I searched on this forum for a while, and I can’t seem to find a way to get a specific Event Instance’s waveform. Most of the time the method written is getting the waveform from a whole channel (usually master).  
Is there any way to get the data from a specific emitter?

Thank you for your time.

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**Author:** ![cameron-fmod](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/cameron-fmod/32/261_2.png) [@cameron-fmod](https://qa.fmod.com/u/cameron-fmod)\
**Post date:** [April 4, 2019, 2:27am UTC](https://qa.fmod.com/t/fmod-2-0-get-spectrum-data-of-event-instance/14499/2 "2019-04-04T02:27:09Z")

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In an example like: [Getting spectrum of master channel in Unity...](https://qa.fmod.com/t/getting-spectrum-of-master-channel-in-unity/12579/2)  
It uses the Master ChannelGroup, although you could apply this to any ChannelGroup including the Events:  
[https://fmod.com/resources/documentation-api?version=2.0&page=studio-api-eventinstance.html#studio\_eventinstance\_getchannelgroup](https://fmod.com/resources/documentation-api?version=2.0&page=studio-api-eventinstance.html#studio_eventinstance_getchannelgroup).

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**Author:** ![cinfa](https://avatars.discourse-cdn.com/v4/letter/c/7993a0/32.png) [@cinfa](https://qa.fmod.com/u/cinfa)\
**Post date:** [May 28, 2019, 10:20pm UTC](https://qa.fmod.com/t/fmod-2-0-get-spectrum-data-of-event-instance/14499/3 "2019-05-28T22:20:01Z")

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Hi! I was trying your example, but I get an error on  
FMODUnity.RuntimeManager.LowlevelSystem.createDSPByType(FMOD.DSP\_TYPE.FFT, out fft);  
It says that LowlevelSystem is an unresolved symbol.  
I’m using FMOD 2.00.01.

[edit] I just found out that I need to use  
FMODUnity.RuntimeManager.CoreSystem

Thank you a lot for that code!

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**Author:** ![dumativa](https://avatars.discourse-cdn.com/v4/letter/d/d9b06d/32.png) [@dumativa](https://qa.fmod.com/u/dumativa)\
**Post date:** [June 13, 2019, 9:12pm UTC](https://qa.fmod.com/t/fmod-2-0-get-spectrum-data-of-event-instance/14499/4 "2019-06-13T21:12:21Z")

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Hi! I was wondering if it is possible to add this DPS to a bus’ channelgroup, instead of adding it to every single event, like this:

```
Bus selectedBus = RuntimeManager.GetBus(BusAddress);
selectedBus.getChannelGroup(out channelGroup);
channelGroup.addDSP(FMOD.CHANNELCONTROL_DSP_INDEX.HEAD, _fftDSP);

```

When I try, I get a ERR\_STUDIO\_NOT\_LOADED on the GetChannelGroup call…

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<div class="post-metadata">

**Author:** ![cameron-fmod](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/cameron-fmod/32/261_2.png) [@cameron-fmod](https://qa.fmod.com/u/cameron-fmod)\
**Post date:** [June 17, 2019, 1:01am UTC](https://qa.fmod.com/t/fmod-2-0-get-spectrum-data-of-event-instance/14499/5 "2019-06-17T01:01:56Z")

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If you try to access the Bus before anything is playing through it, it may not exist yet. You can use [Bus::lockChannelGroup](https://fmod.com/resources/documentation-api?version=2.0&page=studio-api-bus.html#studio_bus_lockchannelgroup) to force the creation of the Bus, just make sure to call [Bus::unlockChannelGroup](https://fmod.com/resources/documentation-api?version=2.0&page=studio-api-bus.html#studio_bus_unlockchannelgroup) when done with it.