# Master Mixer Hierarchy We highly recommend that you set up the correct routing to your sounds so they will then be configurable from the in-game {{< glossterm >}}ui{{< /glossterm >}} mixer. We also highly recommend that you have a look in the SDK templates - supplied as part of the [Wwise Sample Project](using-wwise/) - to get an overview of the games default routing and then use it in your own integration pipeline.     ### Parent Buses When setting up sound routing, there are certain "parent" buses that **should never be used directly** for routing your sounds. These buses are designed as parents to the "child" buses listed in the sections below, and as such all sounds should be routed to the appropriate child, not the parent. Using these parent buses means that your aircraft won't benefit from the in-game UI volume level mixer, nor from the global dynamic mixing structure. {{< image-center src="images/4_Sound/Wwise/wwise_mastermixer_buses.png" alt="Wwise Sample Project Parent Mixer Buses" >}}   The following parent buses should **never be directly routed**:   - Master Audio Bus - game - game\_aux - aux\_inside - aux\_outside - game\_sfx - aircraft\_wwisedata - aircraft\_wwisedata\_ai - aircraft\_wwisedata\_player - inside - outside - engine\_inside - engine\_outside   The following two parent buses are secondary master buses for avionics through headphones, and - like the other parent buses listed above - they should never be routed directly:   - Master\_Headset\_Bus - warnings   ### Output Buses For Cockpit View The table below shows the bus structure for player sounds from the cockpit. All sounds that play from the *inside* view should be routed through these buses: **IMPORTANT**: Each one of these output buses has an {{< glossterm >}}ambisonic{{< /glossterm >}} child bus dedicated to ambisonic takes. For more information, please [see here](https://www.audiokinetic.com/products/ambisonics-in-wwise/ "Ambisonics In Wwise"). {{< table-wrapper >}} | Output Bus Inside | Description | |------------------------|-------------------------------------------------------------------------------------------------------------------------------------| | `combustion_inside` | This bus is dedicated to **combustion** sounds in cockpit view. | | `jetwhine_inside` | This bus is dedicated to **turbine jetwhine** sounds in cockpit view. | | `propeller_inside` | This bus is dedicated to **propeller** sounds in cockpit view. | | `rotor_inside` | This bus is dedicated to **rotor** sounds in cockpit view. | | `grounds_inside` | This bus is dedicated to **ground** sounds in cockpit view, such as, ground roll, or touchdown sounds. | | `instruments_inside` | This bus is dedicated to **instruments** sounds in cockpit view, such as cockpit foleys (pedals, yokes, push button, knobs sounds). | | `miscellaneous_inside` | This bus is dedicated to **miscellaneous** sounds in cockpit view, such as flight control, fuel pumps, hydraulics, and gears. | | `rain_inside` | This bus is dedicated to **rain** sounds in cockpit view. | | `rattles_inside` | This bus is dedicated to **rattles** sounds in cockpit view. | | `walla_inside` | This bus is dedicated to **walla** sounds in cockpit view. | | `warning_inside` | This bus is dedicated to **warning** sounds in cockpit view. | | `winds_inside` | This bus is dedicated to **wind** sounds in cockpit view. | {{< /table-wrapper >}}     ### Output Buses For Outside View The table below shows the bus structure for **player aircraft sounds** coming from the outside viewpoint. All the sounds that plays from the outside view should be routed through these buses.   {{< table-wrapper >}} | Output Bus Outside | Description | |------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------| | `combustion_outside_generic` | This bus is dedicated to **combustion** sounds for piston aircraft in outside view. | | `combustion_outside_turbine` | This bus is dedicated to **combustion** sounds for turboprop, turbofan and turbojet aircraft in outside view. | | `jetwhine_outside_generic` | This bus is dedicated to **turbine jet whine** sounds for little turboprop and turbofan aircraft in outside view. | | `jetwhine_outside_turbine` | This bus is dedicated to **turbine jet whine** sounds for medium to large turboprop and turbofan and turbojet aircraft in outside view. | | `propeller_outside` | This bus is dedicated to **propeller** sounds in outside view. | | `rotor_outside` | This bus is dedicated to **rotor** sounds in outside view. | | `grounds_outside` | This bus is dedicated to **ground** sounds in outside view, such as, ground roll, or touchdown sounds. | | `instruments_outside` | This bus is dedicated to **instruments** sounds in outside view. | | `miscellaneous_outside` | This bus is dedicated to **miscellaneous** sounds in outside view. | | `rain_outside` | This bus is dedicated to **rain** sounds in outside view. | | `rattles_outside` | This bus is dedicated to **rattle** sounds in outside view. | | `walla_outside` | This bus is dedicated to **walla** sounds in outside view. | | `warning_outside` | This bus is dedicated to **waning** sounds in outside view. | | `winds_outside` | This bus is dedicated to **winds** sounds in outside view. | {{< /table-wrapper >}}     ### AI Output Buses for outside view You will find the same bus structure for AI aircraft `SimObjects`:   {{< table-wrapper >}} | Output Bus Outside | Description | |-------------------------|----------------------------------------------------------------------------------------------------------------------------| | `combustion_generic_ai` | This bus is dedicated to **combustion** sounds for piston AI aircraft. | | `combustion_turbine_ai` | This bus is dedicated to **combustion** sounds for turboprop, turbofan and turbojet AI aircraft. | | `jetwhine_generic_ai` | This bus is dedicated to **turbine jet whine** sounds for little turboprop and turbofan AI aircraft. | | `jetwhine_turbine_ai` | This bus is dedicated to **turbine jet whine** sounds for medium to large turboprop and turbofan and turbojet AI aircraft. | | `propeller_ai` | This bus is dedicated to **propeller** AI sounds. | | `rotor_ai` | This bus is dedicated to **rotor** AI sounds. | | `grounds_ai` | This bus is dedicated to **ground** AI sounds, such as, ground roll, or touchdown sounds. | | `instruments_ai` | This bus is dedicated to **instruments** AI sounds in outside view. | | `miscellaneous_ai` | This bus is dedicated to **miscellaneous** AI sounds in outside view. | | `rain_ai` | This bus is dedicated to **rain** AI sounds in outside view. | | `rattles_ai` | This bus is dedicated to **rattle** AI sounds in outside view. | | `walla_ai` | This bus is dedicated to **walla** AI sounds in outside view. | | `warning_ai` | This bus is dedicated to **waning** AI sounds in outside view. | | `winds_ai` | This bus is dedicated to **winds** AI sounds in outside view. | {{< /table-wrapper >}}     ### Aux Buses There are two different Auxiliary Buses available to you when creating audio, both of which are explained below.   #### Game-Defined Auxiliary Sends In the sound XML, the `AcousticParameters` contains several `ReverberationPreset` parameters. These parameters allows you to set up **Shareset** reverbs into custom auxiliary buses (`rev_inside_custom`, and `rev_outdoor_custom`) which will then be used as **game-defined buses**. This means that all sounds that are tagged "using game-defined aux sends" in the `WwiseProject` will be sent to the custom bus with the effect Shareset you defined in the `sound.xml`. {{< image-center src="images/4_Sound/Wwise/wwise_game_defined.png" alt="Game Defined Aux Sends" >}} Doing it this way ensures that every content provider can create their own cockpit and/or outdoor reverberation for their aircraft, by adding the newly created Shareset into the Wwise package. Adding the shareset to the package is done by simply dragging the shareset in the WWise UI onto your soundbank, as illustrated below: {{< image-center src="images/4_Sound/Wwise/wwise_add_shareset.png" alt="Adding A Shareset To A Sound Bank" >}}   You will then need to set up the right Shareset name in the `sound.xml` file. For example: ``` xml ``` Please have a look at the [sound.xml categories](../content-configuration/sounds/sound-xml/) page to see how to correctly set up your acoustic parameters through `sound.xml`.   Here is the list of **Cockpit Reverb Aux Buses** that are shared in the Wwise project. In Wwise, aux bus are available following this Master-Mixer hierarchy path: - `\Master-Mixer Hierarchy\Default Work Unit\Master Audio Bus\game\game_aux`.   {{< table-wrapper >}} | Aux Bus Name | Description | |------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------| | `reflections` | This bus is dedicated to the acoustic reflections that things like engines will make when close to reflective sources like the ground or the walls of a canyon. | | `rev_inside_custom` | This bus is the one where `SharesetInside` is setup for player SimObjects. | | `rev_outdoor_aircraft` | | | `rev_outdoor_aircraft_low_end` | | | `rev_outdoor_aircraft_modulations` | | | `rev_outdoor_custom` | This bus is the one where `SharesetOutside` is setup for player SimObjects. | | `rev_outdoor_custom_ai` | This bus is the one where `SharesetOutside` is setup for AI SimObjects. | {{< /table-wrapper >}}   Finally, here is the list of the **Cockpit Acoustic Sharesets** that already exist in the Wwise sample project. Feel free to use them on your own aircraft:   {{< table-wrapper >}} | Shareset Name | Description | |-------------------------------|-----------------------------------------------------------------| | `rev_inside_generic_airliner` | Convolution Reverb using IR captured in ATR 42 600 | | `rev_inside_generic_medium` | Convolution Reverb using IR captured in TBM 930 | | `rev_inside_generic_small` | Convolution Reverb using IR captured in SR22 | | `rev_inside_generic_custom` | Convolution Reverb using IR captured in ATR 42 600 | | `rev_inside_c152` | Convolution Reverb using IR captured in Cessna 152 | | `rev_inside_c172n` | Convolution Reverb using IR captured in Cessna 172N | | `rev_inside_c172sp` | Convolution Reverb using IR captured in Cessna 172SP | | `rev_inside_CabriG2` | Convolution Reverb using IR captured in Cabri G2 | | `rev_inside_cap10c` | Convolution Reverb using IR captured in Cap10 | | `rev_inside_da40` | Convolution Reverb using IR captured in a Diamond DA40 | | `rev_inside_da62` | Convolution Reverb using IR captured in a Diamond DA62 | | `rev_inside_dr400` | Convolution Reverb using IR captured in a Robin Dr400 | | `rev_inside_dv20` | Convolution Reverb using IR captured in a Diamond DV20 | | `rev_inside_FDCT` | Convolution Reverb using IR captured in a Flight Design CT | | `rev_inside_pipercub` | Convolution Reverb using IR captured in a Pipercub | | `rev_inside_pipistrel` | Convolution Reverb using IR captured in a pipistrel Virus SW121 | | `rev_inside_pitts_s2s` | Convolution Reverb using IR captured in a Pitts S2S | | `rev_inside_savage` | Convolution Reverb using IR captured in a Zlin Savage Cub | | `rev_inside_sr22` | Convolution Reverb using IR captured in a Cirrus SR22 | | `rev_inside_tbm930` | Convolution Reverb using IR captured in a TBM 930 | | `rev_inside_vl3` | Convolution Reverb using IR captured in a JMB VL3 | | `rev_inside_xcub` | Convolution Reverb using IR captured in a Cubcrafter Xcub | {{< /table-wrapper >}}   #### User-defined Auxiliary Sends For outside reverberation, you can also use generic buses that we have shared with the community. All default aircraft models are using these buses with the user-defined mode. For example, here is the generic **Outside Reverb Aux Bus** available in the Wwise project: {{< image-center src="images/4_Sound/Wwise/wwise_user_defined.png" alt="User Defined Aux Sends" >}}   Every content provider can use the following as `user-defined` buses:   {{< table-wrapper >}} | Aux Bus Name | Description | |------------------------------------|-------------------------------------------------------------------------------------------------| | `rev_outdoor_aircraft` | This is a generic outside reverb for aircraft. | | `rev_outdoor_aircraft_low_end` | This is a generic outside reverb with more low end. It is mainly designed for airliners. | | `rev_outdoor_aircraft_modulations` | This is a generic outside reverb with some EQ modulation. | | `rev_outdoor_custom` | This is a generic outside reverb for aircraft, created for you to customise for your own needs. | | `rev_outdoor_custom_ai` | This is a generic outside reverb for AI aircraft. | | `disto_overspeed` | This is a generic distortion effect used in the case of over-speeding with an aircraft. | {{< /table-wrapper >}}     #### Early Reflections An early reflection bus has been created for use with Microsoft Flight Simulator 2024 aircraft. This bus is designed to simulate the way sound is reflected from close physical objects like the ground or the side walls of a canyon. In general this bus is required for the for the engine sound effects (see here for details: [Early Reflections](aircraft-audio/advanced-audio-effects/#reflections)), but it can be used for *all* external sounds to add further realism. {{< callout context="note" title="NOTE" icon="outline/bulb" >}} This bus will require that you have installed the [Reflect Plugin](https://www.audiokinetic.com/en/library/edge/?source=Help&id=wwise_reflect_plug_in_effect). {{< /callout >}}   Using this bus is simply a case of routing your exterior sounds to the **Early Reflections** bus named "reflections" in the Master Mixer Hierarchy, as shown below: {{< image-center src="images/4_Sound/Wwise/wwise_reflect_bus.png" alt="Setting The Early Reflections Bus For An Engine Sound" >}}     ### Secondary Output Buses The `Master_Headset_Bus`, as its name suggests, is a secondary Master bus dedicated to sounds heard through headphones using the **Communication Device output bus**. This is where you can route avionics warnings that are supposed to play in the user's headset.   {{< table-wrapper >}} | Output Bus Outside | Description | |--------------------|--------------------------------------------------------------------------------| | `warning_signal` | This bus is dedicated to warning signal sounds that come through user headset. | | `warning_voice` | This bus is dedicated to voice warnings sounds that come through user headset. | {{< /table-wrapper >}}     ### Ambisonic Output Buses The `Master_Headset_Bus`, as its name suggests, is a secondary Master bus dedicated to sounds heard through headphones using the **Communication Device output bus**. This is where you can route avionics warnings that are supposed to play in the user's headset.   {{< table-wrapper >}} | Output Bus Outside | Description | |--------------------|--------------------------------------------------------------------------------| | `warning_signal` | This bus is dedicated to warning signal sounds that come through user headset. | | `warning_voice` | This bus is dedicated to voice warnings sounds that come through user headset. | {{< /table-wrapper >}}