after doin' the usual female/male vocal voice tests ( i recommend "the unaccompanied voice" on the secretly canadian label; fairfield four, "standing in the safety zone"; lyle lovett, "joshua judges ruth"; and, eva cassidy, "live from jazz alley," among many), you should move on to some more complex stuff with which you're familiar. my choices (this week) include: phish, "rift," bands 3&4; radiohead, "kid a"; pink floyd, "the final cut" band 1; mark knopfler, "sailing to philadelphia"; and, the eagles, "hell freezes over." i then move to some "dynamite" tracks as a final test; these include, by way of example: stephen stills, "stills alone," "treetop flyer"; lou reed/john cale, "songs for drella," "open house"; "strike a deep chord: blues guitars for the homeless," "brother can you spare a dime" and "america the beautiful" (dr. john & odetta); the eels (i have this on a cd done by a dutch radio station), "susan's house"; rickie lee jones, "pop, pop," "dat dere"; and, hugh masekela, "hope," "stimela." with the cd's listed, i can listen to any component in any system and judge it within an hour or three. it must again be emphasized these are MY test discs/tracks. you should develop your own, based on YOUR tastes and YOUR listening experiences. moreover, MY choices change from month-to-month and week to-week. -cfb