Wilson used to use scan speak and focal. They are still using focal, but now they are using a modified sb acoustics. At least in the sasha. Audio note builds their own. Joseph audio, snell, sony (ar-1), sonus faber, consensus audio, triad, fritz, Martin design, These are just off the top of my head. There are many others. I would guess that even some big names like YG Acoustics are using off the shelf. The reality is that many more companies than people realize are using off the shelf drivers. A handful of manufacturers do make their own in house. Harman, B&W, paradigm, audio note..