I’m not sure how they can market this as a 12 channel mixer. It’s got four mono channels and two stereo channels. I suppose the two stereo channels with four inputs total could bring it up to an eight channel mixer but even that’s a stretch.Maybe the alternate three and four outs figure into it someway, but that does not increase the inputs. Maybe the 2 auxiliary inputs for effects and monitoring are considered channels?? ... so the way I see it, it’s eight total inputs on 6 channel faders. This being said, I think it is a quality unit with a good sound.... and for most applications maybe eight is enough.