We just released some new software that changed the sound of our PerfectWave DAC. As is normal there's debate on whether or not those changes are better or worse. For me there's no question they are better in every respect - but only after I retuned my system to take advantage of the changes.
I think it's instructive to remember that your system has been setup and tuned to optimize the equipment and environment at the time you did the work. It is therefore illogical to assume that changes in equipment or environment can be effectively judged without revisiting your setup.
For example, when I first auditioned the new software I liked everything I heard - greater soundstage, better depth, improved space and separation of instruments - but there was also a slight added harshness and over emphasis on the top end that sounded unnatural.
I could have simply assumed it was wrong and went back to the drawing board or - and this is important - I could have reexamined my setup. It turns out that when I originally setup the Maggies I didn't have enough top end and solidity of the center image so I toed them in slightly. Bingo, the image popped into focus. But that was a few months ago.
With the recent change in software I simply removed the toe in and the slight upper harshness vanished and in its place and even deeper and wider soundstage appeared with an even more convincing three dimensional image.
So it begs the question - which was correct? My first setup and the original software or the new setup and the new software?
The answer is both as long as you are willing to redo your assumptions.