# DSP metering - Head or Tail?

**URL:** <https://qa.fmod.com/t/dsp-metering-head-or-tail/13317>\
**Category:** FMOD Studio\
**Created:** [July 27, 2017, 12:05pm UTC](https://qa.fmod.com/t/dsp-metering-head-or-tail/13317 "2017-07-27T12:05:27Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![sperryrand](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@sperryrand](https://qa.fmod.com/u/sperryrand)\
**Post date:** [July 27, 2017, 12:05pm UTC](https://qa.fmod.com/t/dsp-metering-head-or-tail/13317/1 "2017-07-27T12:05:27Z")

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Hi,

A quick question, (which i’m sure the answer to which is somewhere in the docs)…

If I want to get the _final_ output volume levels of a channel, do I setMeteringEnabled on the Head or Tail of the DSP chain?

Thanks in advance,  
MM

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<div class="post-metadata">

**Author:** ![sperryrand](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@sperryrand](https://qa.fmod.com/u/sperryrand)\
**Post date:** [July 27, 2017, 8:26pm UTC](https://qa.fmod.com/t/dsp-metering-head-or-tail/13317/2 "2017-07-27T20:26:09Z")

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OK. So it looks like CHANNELCONTROL\_DSP\_INDEX.HEAD gives you the _output_ end of the DSP chain, and CHANNELCONTROL\_DSP\_INDEX.TAIL gives you the _input_ end.

For example:  
Tail = the sound source (e.g a .wav file)  
Head = values sent out to the speakers.

So in my case, where I’m upmixing a mono sound to 7.1, I have 3 DSP’s with indices 0, 1 and 2

DSP 0: 8 input channels, 8 output channels = HEAD  
DSP 1: 1 input channel, 8 output channels  
DSP 2: 1 input channel, 1 output channel = TAIL

MM