We've converted the sound system to an Audio Mixer system. This system lets you play particular sounds through a particular mixer. This mixer can then have its own volume and other processors.
For example, you could have a mixer called "Weapon" as a child of the "Game" mixer. You could decide that all of your weapons are too quiet, so turn up the volume of your Weapon mixer. But then you might want to add some echoey reverb to all the game sounds in your scene, but not affect music or ui sounds, so you can add a processor to the "Game" mixer.
This system is still a work in progress, but it's infinitely more configurable than what we had previously.