They are not all they way up.. I think they are about 20% max. But how would you use the JBL presets for example? They assume, that the amp gains are set the same for both LF and HF. The same goes for the Synthesis systems which use SAM1HF/SAM2LF. The DBX should perform equally to the BSS London units (at least according to specs). But I'll try the DBX in a couple of weeks and see how bad the hiss is.