There certainly are huge variances in the quality of recordings themeselves, and of the sonic choices the engineers and producers make in the tracking and mixing of music albums. I have numerous recordings where the lead vocals were recorded in different studios, and in some instances by different engineers, with the difference in timbre clearly evident from track to track.

Even albums recorded by the same engineer have variances from track to track because of instruments/vocals being reorded and/or mixed on different days over a period of weeks. The mastering phase is supposed to even out these variances, but it is impossible to correct them all, such as different sounding lead vocals when the rest of the ensemble was recorded seperately.

Many home systems are not set up ideally, with compromises made in speaker placement and room acoustics to acommodate room decor and furnishings. These compromises will make subtle differences in a recording more difficult to hear than in a situation where a room is set up for music listning only, with no placement or acoustic treatment restrictions.