CD Quality Compared to MP3 Quality

[Nighthawk69]

Hi there....

I have been wondering for quite sometime now, what are the equivalent specifications (bitrate, etc.) of an MP3 to that of an audio CD? In other words, what specs (bitrate, etc.) would an MP3 need to be set at to achieve CD quality?

Thanks!

 

[erikiksaz]

I think it's 256, but that doesn't always apply, as MP3 quality greatly depends on the quality of the encoder used. I'm sure plenty of people here can also support or reject this

 

[CSFM]

As far as I know you cannot achive CD quallity with an Mp3.
Click this link it should clear it up a bit.

Anands FAQ on Mp3's

-CSFM-

 

[Nighthawk69]

Ahh, I see... thanks!!

 

[Zlash]

Cd quality is 44,100 Hertz and 128kbps encoding and you can acheive way over CD quality if you so choose =), up to 320 kbps with normal encoding software.

 

[Nighthawk69]

Zlash: That sort of confuses me... I am reading in the above linked FAQ that CD quality cannot be achieved with MP3's, yet you are saying it can...

 

[Escalade]

<< ...you can acheive way over CD quality if you so choose >>


MP3 uses lossy compression (think of it as the audio equivalent of JPEG); it can never be equal (or better) than CD quality.

 

[Nighthawk69]

Let me take a stab and clearing this up for myself and some of you guys can correct me where I'm wrong...

The way I now understand it is that the MP3 encoding actually removes some sound in the audio file to make it much smaller than a normal file from an audio CD. Now, the quality is the same or better though once it is converted to an MP3, yet it just lacks some of the sound information which the encoder removed.

Am I correct in saying this?

 

[CSFM]

You might be able to rip the CD down in a higher Bit rate but the contents of your data will not be of a higher quallity. Unfortunatly it's not all that easy...

 

[Zlash]

Actually i think i messed that up, it might be 160kbps that is CD quality. It does not say in that FAQ that you cannot get CD quality, remember that the compression is removing the parts of the song that humans cannot hear anyway, 320kbps which is the highest mp3 bitrate i know of is very good quality sound. Lemme look something else up rq too =).

 

[Escalade]

<< ... MP3 encoding actually removes some sound in the audio file to make it much smaller... >>


Yes. That's whats called lossy compression.



<< Now, the quality is the same or better though once it is converted to an MP3, yet it just lacks some of the sound information >>


The quality of MP3 can never equal "CD quality" - it might sound just the same to your ears, but is vastly different from the original CD copy... once you remove audio information it is no longer an exact copy of the original.

If you took a MP3 file and converted it to a WAV file then convert that WAV file back into MP3, and repeat this experiment about 5-10 times, using the last MP3 you created - you'll begin to see exactly what lossy compression does to the resulting audio file.


Clear as mud, right?

 

[Nighthawk69]

OK, gotcha! Thanks Escalade!

 

[Zlash]

Escalade your not losing any quality converting a wav to a mp3 at good bitrate. Unless you determine quality by huge wave files with all sorts of unhearable noise added in =).

 

[Nighthawk69]

So the sound that is removed by the MP3 encoder is truly sound that you cannot hear or play through a quality sound system?

 

[Zlash]

Just think of it as cutting the fat off a steak after ya cook it.

 

[CSFM]

It actually reduces the frequency. So what you hear is a lot different. I can easily hear the difference in my CD walkman between CD and Mp3 formats using just a standard pair of Sony headphones. Some encoders take out the highs and the lows (frequencies), and some encoders take out sections, or parts of the audio from each frequency to reduce the size of the file, while also compressing and reformatting the file. I personally think the encoders that take the highs and lows out have a lower sound quality compared to the others. I use Creative Play Centre 2 to rip my CD's into Mp3. I found that the sound was great. Of course none of this really matters if you don't have a good sound system to play it back on.

 

[CSFM]

>>>>Just think of it as cutting the fat off a steak after ya cook it.<<<<

Kind of right... but some people like to eat the fat! As some people like sound quallity.

 

[Zlash]

Just in this case the fat does not affect quality =).

 

[CSFM]

>>>Just in this case the fat does not affect quality =). <<<

Sorry to tell you this, but your wrong. There is a desernable sound difference between Mp3 and CD. I can hear it not only in the sound but also in the volume levels... no matter what bit rate or encoder you use you are loosing quallity.
Don't want to start a flame war though so I will leave you with it!

-CSFM-

 

[Nighthawk69]

Thanks for the great information guys!

 

[Escalade]

<< ...There is a desernable sound difference between Mp3 and CD... >>


I totally agree!

It *might* be removing frequencies you can?t hear, but that depends a lot on the ambient conditions; if you?re playing MP3s in your car, you?ll never hear the difference, but on an exotic home system, under ideal listening conditions, the difference is very clearly discernable.

This is getting into an audiophile discussion, but even ?CD quality? isn?t a perfect reproduction of the original sound, because it?s sampled at some frequency with a notch filter at the high and low frequencies. The newer SA format is a bit better, but the ultimate sound format is still analogue... no matter what digital audio format you use, you loose much of the warmth and depth of the music... of course all this depends on what tube amps you?re using as well.

 

[Zlash]

See you can't really sit here and tell me, oh there's a difference because for all i know your listening to poorly encoded MP3s in which there would be a difference. With a high quality MP3 you cannot tell the difference.

 

[Workin']

<< See you can't really sit here and tell me, oh there's a difference because for all i know your listening to poorly encoded MP3s in which there would be a difference. With a high quality MP3 you cannot tell the difference. >>

Rest assured, there IS a difference. Whether you can tell or not is subject to many variables. An 8:1 data reduction (or higher) means *something* is gone - and to claim it's just noise or stuff NO one can hear gives the mp3 encoder entirely too much credit for intelligence!

That said, using the LAME or Fraunhofer mp3 encoder at 256kbps or higher will produce an mp3 file from MOST material that can't be reliably distinguished from the CD original. SOME material can't be transparently encoded by ANY encoder, so speaking in terms of absolutes is a waste of time.



<< This is getting into an audiophile discussion, but even ?CD quality? isn?t a perfect reproduction of the original sound, because it?s sampled at some frequency with a notch filter at the high and low frequencies. The newer SA format is a bit better, but the ultimate sound format is still analogue... no matter what digital audio format you use, you loose much of the warmth and depth of the music... of course all this depends on what tube amps you?re using as well. >>

If you think a vinyl record is a perfect reproduction of the original sound you must be using very powerful drugs. OK, I get it, you are joking

 

[Jman13]

What I'd like to see is a double blind study done with self-proclaimed audiophiles where the same track is played in MP3 format and CD format. One has to choose which is the CD and which is the MP3. Do it for 96, 128, 160, 192, etc. If any of those bit rates is able to get the group to pick the MP3 over the CD ~50% of the time, you can say it's CD-quality (to our ears). You have to make it so they have to pick one...no "they're both CD, or they're both MP3" choices. That way, at 50%, you reduce it to chance of guessing the correct format.

Personally, I can tell the difference (through headphones) of most 128kbps encoded MP3s. At 160, I can not discern any difference between the two. Of course, I don't have a professional sound system. For all intents and purposes, very few people will be able to tell in casual listening that a 128kbps MP3 is not a CD. If you really listen, you might be able to tell...depends on the person.

I REALLY want a study!!!

Jman

 

[Zlash]

Technically i from what i calculated from the book CD quality is 172kpbs, if they think they can tell the difference from 160 on up i'd be skeptical =).