What's the use of 20 and 24 bit DACs with CDs?

Many standalone players and modern DACs are now using 20 and 24 bit DACs. Is there a significant advantage to doing so with a 16 bit recording? Are these players and DACs doing upsampling on the original 16 bit signal to take advantage of the DAC or are we just looking at extra bandwidth that is being squandered for the sake of advertising? To me, the extra bandwidth doesn't seem to be merited unless there is upsampling or HDCD involved. Opinions?
The typical DAC chip of a typical mid-fi CD player does not actually out-put a 16 bit word length. Even the good DACs often only achieve 14 bit words at best-- this is with a 16 bit DAC chip. But when 20 to 24 bit chips are used, the DAC can more closely approach or actually achieve true 16 bit words, and thus produce more "information" or detail from a 16 bit encoded CD.

The "word" length in bits has nothing to do with the sampling rate. Even a typical inexpensive CD player uses 8X oversampling, which yields an actual sample rate of 352.8 KHZ. Over-sampling and up-sampling are essentially the same thing, but recently the term "up-sampling" has become a buzzword to help sell allegedly better CD players.

"Better" CD players are better (and more expensive) because of the use of the highest quality parts, ie DAC chip sets and other parts, and excellent engineering, design, and implementation. Levinson also uses 8X oversampling, but uses the best quality parts and implementation. I am not an expert in this but took a big interest in it (and did a lot of research) prior to purchase of the expensive Levinson 360S DAC. The 360S is an absolutely great DA Converter, but there are others. Cheers. Craig
Great response Craig! It's the same as a car. The speed limit is 65, so why get the Turbo V6, when the standard 4 cylinder will get you there.
A couple of points more here. When a 16 bit word is read from a cd, some form of processing, typically rate conversion, is needed to produce a 24 bit word from the 16 bit word. The rate conversion can be done inside the D/A chip, or it can be done in a processor preceding the D/A. The 24 bit word does not increase the information in the original signal, but just represents with higher precision the mathematical product of the 16 bit data word with the rate conversion filter coefficients. So Cjcerny is correct in assuming some form of processing to get from 16 bits to 24 bits.
Secondly, upsampling (typically done in a processor) can be significantly better than oversampling, 8x or otherwise, done inside the D/A chip because the quality of the upsampling filter can be much better than that used in most D/A chips - so there can be a significant difference in upsampling vs oversampling depending on where and how the rate conversion is done.
Thirdly, Cjcerny is correct in using the term 'bandwidth'. Bandwidth is frequently used in digital processing to mean total bits per unit time (e.g. the increased bandwidth of DVD), and not just to mean spectral bandwidth.
Sugarbrie: i have to disagree with you on that one..
this is my personal limited thinking but..
i think that we have only 1 life to live..and time passes only once so it is more important HOW you get from A to B then just getting there...isn't that why people here invest soo much money and time on getting what they defines as great sounding equipment ?

The turbo V6 is alot more fun!
Of course you'll need the sport suspension
"why get the Turbo V6, when the standard 4 cylinder will get you there?"

you need to get out more! rent a ferrari for a day, then come back and tell us if you still prefer your buick.

-s2k, F1 hopeful
I think that you guys misunderstood Sugar. If i'm reading him right and the fact that he agreed with Craig, he was trying to say that total performance as compared to basic functionality is a key factor. That is why someone would want to "upgrade" rather than stay with something that "works". This is just a guess, but i don't think that he was advocating taking the cheap or generic route. I do however think that he ( along with I and many others ) are great fans of products that offer big bang for the buck. Sean
I've owned the ARC DAC 2, then changed and used the Perpetual Technologies P-1A, P-3A combination and it sounded much more open and revealing. I had Dan Wright do a level I modification to the P-3A and I felt it was truly worth the money. I've since sold them to purchase and try other DACs. I then purchased an EVS M-2 (which was nice, but not as nice at the Perpetual gear. Ric was nice enough to allow me to return it (great person). Recently I've purchased the new Kora Hermes 24/192. It is a tube DAC and I've replaced the 2 tubes with the Seimens NOS E88CCA pair and the sound is as wonderfully transparent and anything I've tried to date. I know that many new digital formats are right around the corner, but until the industry cuts us audiophile a break and settles on one format (which will never happen), I think I've found my DAC.....

But like everything....that's just my opinion!

Good luck in your search.
Settle down boys and girls. I was only posting how some people think, not me; ie, why buy a Turbo 24 bit when a 16 bit produces sound. The 4 cylinder people buy Bose.
I remember when Primare first came out with the 24 bit CD player. The dealer sure made a big deal about it. I think his words were "higher resolution" and "more detail."

At the time it made sense to me. I thought if a video source can benefit from a line doubler which enhances the video resolution, then a faster processor that translates bits into audio signals should benefit the quality of the sound as well by enhancing the audio resolution.

Do we all hear the "higher resolution" benefitted by having more bits? If not, then how do we harness the full potential of high resolution CD players? That's what I want to know.