Testing a new component with only one criteria (I.E. judging by vocals only) is extremely limited in my opinion. Whenever I test out a new component or device (unless it is so bad, it's outta there within 5 minutes), I listen for the entire gamut of what that component offers.
Is there a tonal balance shift? Did the overall sound stage stay the same, increase or shrink? To what extent did the individual instruments and singers image get improved, warped, out of focus or changed? Did the timbre and tone change at all? Does the new component offer a quietness not known before? Does it increase or shrink the depth perception? Is their a height change? Are certain (or the entirety of) things more forward? Is everything equal (like no exaggerated bass, cymbals or horns) in sound? Does it sound natural? Did it increase my wanting to listen or take away from it? Did it improve or decrease the dynamics, visceral impact, the involvement? Am I still being drawn into the music or am I looking for excuses to do something else? Did I lose any of the micro or macro dynamics? Were they improved? Wow, these things don't even scratch the surface of what I evaluate with a new component in a system.
Usually, I know rather quickly if I will like something or not. If it's just a slight change or things get worse, then I have to hear some potential. If not, then it usually doesn't last very long. Some items that only last 5 minutes offer absolutely no potential. Case in point with two differing items I introduced into my rig at different times.....that had potential...
The first was the QSA R&B fuse. Good lawd, I HATED that thing when we first put it in. All I wanted to do was take it out and get back to the sound I had. BUT, as I listened, I would hear something that I was like, "Hey, that sounded fantastic! I hadn't noticed that before done so well". Then a little later, I would hear something else that let me know, hey...this thing has potential. Long story short - 2 very grueling weeks later, it finally started to come into fruition and at that point, I purchased it. It just kept getting better and better as time marched on and now I wouldn't ever want to listen without it. During those 2 weeks, the swings were radical. From overwhelming, slow and bloated lower registers, to vocals that shifted all over the place and instruments that became obnoxious (which was never the case prior). Literally everything changed and again, at first, I hated it. But, as time marched on, the swings would lessen and those moments of "potential" would improve and get much more commonplace.
The second was the Muon Pro. Yet another product I hated when it was first installed. 2 weeks of listening to what I akin to listening to your system on meth, while candy flipping with lawd knows whatever other drug is out there....oh, it was horrible. Just like with the QSA fuse, the worse the swings got? The more they came back into fruition, and with a vengeance. Then it started sounding much better than prior to install. In this case, I already knew what the end result would be because I heard what it did to a friend of mine's system (who's rig I am very familiar with). So, in that case? I knew what was coming.
Getting back to evaluating. Like Mike L and wil had mentioned, it sometimes takes weeks+ and instead of using just one criteria, I put it through the most demanding of stress tests. Multiple genre's that include the heaviest of passages, as well as the softest of passages with dramatic swings. And everything in between. It can't just pass with one or 5 things that it must do well, it has to pass with the vast majority of things I look for in a component, with no degradation (especially severe) of any other of the criteria I look for. Evaluating just based on a voice (to me) just seems so limited in scope.
But I know you, Ron. You are very specific in your approach to sound. No one (AFAIK) will ever change that. If you are happy with simply monitoring the voices? We should all be happy for you. For sure, I could never do that.
Tom
