FMOD is a fantastic audio engine that you can integrate with Unity. What's more, it's totally free if your studios' yearly revenue does not exceed $200k. (This of course may change!)
FMOD allows greater control over the audio in your project, providing an easy to use interface allowing editing even the most minute sonic detail a breeze. Fortunately a dedicated FMOD Unity plugin makes this process even easier.
Register an account with FMOD
Firstly register an account with FMOD, this is required before you can download any of their applications.
Navigate to the download section of their website, here. You will need to download FMOD Studio, make sure you click the appropriate link for your operating system. At the time of writing FMOD supports Windows, Mac and Linux. Once downloaded, run the installer like you would any other application. Once complete, open the application and create a new project. At this stage we recommend simply saving the project in a directory of your choice.
Link FMOD to Unity
Next, we will need to download the FMOD for Unity package. To add, navigate here to the Unity Asset Store, and find the FMOD for Unity package. If you don't have an account with the Unity Asset Store you will need to create one. Once logged in, click on 'Add to Assets'. Then click 'Open in Unity', this will take you to Unity's Package Manager. Inside the Package Manager click 'Download' to download the package. Once downloaded, click 'Import' and import all of the files. On completion, FMOD will show it's setup wizard. Follow the steps to complete the setup.
Keep clicking through the wizard. On finding this tab:
Link the Project you have just created.
On the next tab, FMOD will attempt to remove and replace any existing Audio components with it's own. Click on 'Replace Unity Listener with FMOD Audio Listener'. Our project was empty aside from the default camera, but you may have other Unity Listeners in your scene. It is recommended to use this tool to replace them all.
The wizard will also prompt you to disable the Unity built-in audio, definitely disable this when prompted.
FMOD is now integrated with Unity! This handles the setup between Unity and FMOD, but I bet you'll want to create a sound to test the connection. Check out the next tutorial here to play a one-shot sample via FMOD.