I was experimenting with something one the last saber I put together. Nothing new or ground-breaking, but it was a departure for me and the way I typically do things. I put the speaker with a very small (0.5") resonance chamber directly behind the heatsink. The soundboard fits directly behind that, that the battery holder behind that. Even though the saber is fairly packed to the gills, there's enough room for air to travel and I get a full, robust, loud sound from the rear of the saber.