why are some cd's so bright sounding

Not all companies who process recordings these days are as concerned about "musicality" and studio "rightness" of sound. "Get that product out there" seems to be 95% of the marketplace, but lets not forget, 95% of the marketplace owns cheap hi-fi. Producers often add their own "soundglazing" or overproduce to compensate for todays mass-market playback equipment. Let's not always blame the producers either!.... Most recordings sound thin, bright,hard and equalized, simply because that little extra effort was not spent in the mixdown process. Recording engineers know what sounds right, for the most part, but they are always limited by budgets, time and direction. This could also be the way the artist wanted it, and lastly, let's not forget, digital will NEVER equal good analogue although they are getting closer over the yrs.

The problem is that they are not properly equalized .

The problem is that they are not properly equalized .

I agree, Chris Isaac's latest is an earbleeder - it's too bad, and it's surprising because some of his earlier recordings sounded really good. I would love to hear some of his stuff recorded to audiophile standards - his smoothness and precise guitar playing lends itself to that. You'd think Isaac would be hip to that jive.

My guess it that it was ruined in the mastering (when it's transferred from the mixed studio master to a CD master). They often run through graphic equalizers and compressors and all sorts to get "the sound they want". The sound they want is a good sound on a boom box, car stereo and mini system .. because that's what most people own. I expect in the US the car stereo is the primary listening source.
Unfortunately hifi buffs are a small percentage of total listeners and don't get a say in the sound quality.