I've already optimized the code for not reloading Sound Groups in the Inspector, but that's just a huge Inspector to render, so it's going to be slow no matter what I do. You can use the bus and/or Sound Group text filter to show less groups at a time, and that should be a bit more responsive. You should really be making extensive use of Dynamic Sound Group Creators, with one on each character with their dialog, so that only the characters who are in the Scene and active at the time will have their Sound Groups in the mixer section, and not all of them all the time. Read about DSGC's here: http://www.dtdevtools.com/docs/masteraudio/DynamicSoundGroupCreators.htm You may want different dialog categories, like NPC's, player, enemies, etc. Maybe make different buses for those.