You dont need to layer anything , the basic form of a psytrance bassline is a 303 bass, this is the bass sound produced by the first acid machine (roland tb303) their now very rare synths but u can get of course a vst one,,my recomendation is the Audiorealism Bassline , it is the best emulation of a 303 bass available, try it before buy it.lol u can even get one from limewire , luck