There is a no "always" answer to your question. Let me explain: Great sounding "high end" electronics do not have these bass and treble controls. This is because these controls impart phase shifts when they are utilized . Read; somewhat smeared, less coherent sound quality that is noticable in a serious sound system (in which you sit equadistant between each speaker ...this is how us "high end" guys seriously listen to music ). Now, if you are comparing speakers with a receiver or integrated amp, which has these tone controls. This unit was probably not designed to have transparent ultra "high end" sound qualities. I have found that these "mid-fi" products sometimes need to have a reduction in treble (due to their harsh treble), or a partial boost the bass to sound half decent and tolerable. In the end, I think the answer to your question depends if you plan on always using a unit with these type of controls, or eventually plan on upgrading to a better, "high end" electronic front end (that probably won't have the tone controls).If you plan on upgrading, then don't fool around with the controls when doing a speaker audition ,i.e. keep them at the 12:00 position. On the other hand, if you always are going to use mid-fi electronics, then consider using the settings that you prefer on the tone controls. This will show you how each speaker reacts to these tonal colorations that you prefer.
