Does a consumer CD player attempt to smooth out the sound at all? In other words, does it attempt to alter the sound a little bit, rather than just reproducing the bits as accurately as possible? I think the answer to that question is no:

I think I have to disagree with you here, Tony.

In my limited and entirely empirical experience, there is a really big difference from one CD player to the next, with everything else (i.e., same CD, same amps, same speakers, same listening environment) being equal.

I have now had four different head units in my car: A Sony CD player, an expensive Panasonic CD player, an inexpensive Panasonic CD player, and the Mark 2 empeg. Each has shown markedly different sound characteristics.

The Sony was probably the most accurate. Because of the acoustic characteristics of my setup (speaker size/brand/location, shape of the interior, etc.) it was a continual battle to get enough mid-range, to the point I had to always keep the "loud" setting on.

The expensive Panasonic was a disaster. It was one of the "gee-whiz" players, aimed at teenagers who wanted to impress their friends more than listen to music: all crispness and definition was gone, mid-bass and bass seemed to blend into an amorphous whole, and the whole effect was one of unobtrusive smoothness -- sort of Montovani-like even when playing Rush. That CD player stayed in my car for two days, to be replaced by...

The inexpensive Panasonic CD player. All the crispness, definition, and punchiness was back. Plus, so much mid-range that not only did I have to turn the "Loud" off, but I had to install L-pads to attenuate the three mid-sized speakers in the front of the car.

I may be mistaken, but I believe the primary design differences among these three units was the DACs. I'm not technically knowledgeable to discuss things like 8-bit, 16-bit, 20-bit etc., but I do believe the designers of the DACs in those three players each had their own ideas about what the output was supposed to sound like, and they implemented those ideas.

Now, the fourth unit, the empeg, is a different case altogether, because there are a few extra variables thrown in, most importantly the fact that it is reading compressed files. That aspect aside, the empeg is like the Sony, but more so. With flat equalization, my mid-range is deficient, and there is a definite harshness to the sound -- I think "strident" is a very good descriptive word. My stereo shop man says this is not surprising -- in his experience, the more signal processing that is done, the more "sterile" and bright the sound, and apparently the empeg does a lot of signal processing.

In other words, CD manufacturers do manipulate the sound output of their players according to the whims of their engineers. It is up to the end users to compensate for these manipulations with whatever tools are available -- speaker placement, amp gains, equalizers, etc. Depending on the preferences of the listener, these compensations may be large or small.

tanstaafl.

"There Ain't No Such Thing As A Free Lunch"