MP3s to CD-R/RW...

[PearlcorderS701]

Due to an increasing -- alarmingly so in my opinion -- lack of available CD singles of new tracks to emerge on the airwaves I would want to buy, I have been forced to download a lot of them via MP3 files online. But the way I do this is to download the file into a folder on my computer's desktop, then use CD Burner XP to burn the files onto a CD-R or CD-RW disc -- however, I choose the "AUDIO CD" option when burning, not the Data Disc option, and thus I had a question about this process...

Indeed, I realize MP3s are highly compressed versions of music/CD tracks, but when I burn the files onto a CD-R or CD-RW, why is it that I don't need to "adjust any levels" when the burning is taking place? In other words, I just click the "burn" icons to get things going, but how does the CD Burner XP program "know" how to "transfer" the MP3 file onto the CD-R in terms of the audio's range and levels? Is there no such thing when burning MP3 files? Do they just burn over as-is, as compressed MP3 codes with no way to "adjust" their "output range" for a finalized CD-R recording?

When I do my final "mixdown" for the CD-R or RW I'm going to play in my car of these mixed compilations I do, I always end up burning the final disc on my TASCAM CD recorder -- in other words, I take the CD-R or RW that contains the burned MP3 files (from my computer and the CD Burner XP) and put that disc into my Marantz CD changer, then burn from there onto a different CD-R or RW on the TASCAM (using different source discs fed into the Marantz)...I realize this sounds like an unnecessary waste of time and energy to do it this way, but I prefer this method because I'm not getting all my songs via downloaded MP3s -- some of them are still off CD albums and CD singles. But once in the Marantz, hooked up digitally to the TASCAM recorder, of course, I could alter recording signals there if I wanted to, but I was wondering why I don't have the option to control the MP3 files' levels when burning in the computer...

 

[Hi Ho]

It seems you are confusing lossy data compression with dynamic range compression. MP3's don't compress the dynamic range. They remove data that we supposedly can't hear. When you burn them to a CD it simply decodes the MP3 file into a WAV that goes on the CD. It doesn't make any difference whether you burn them to a CD and record from that to another CD or just burn them directly to a CD along with the "real" songs.

The levels will be the same. Here is a comparison of the same recording in both WAV and MP3 form.



As you can see, the waveforms look virtually identical.

 

[TLS Guy]

As Hi-Ho explained. Dynamic range compression and digital compression are totally different animals. The former narrowing the db difference between soft and low level signals. The latter throws out bits that are considered unimportant from a psycho acoustic point of view. When you copy the mp3 to CD the average level and dynamic range are unchanged.

You can use the CD from your computer. Your next step makes no sense and is a complete waste of time. It will degrade quality further.

You have made your share of bazaar posts, but this one takes the cake.

 

[PearlcorderS701]

It seems you are confusing lossy data compression with dynamic range compression. MP3's don't compress the dynamic range. They remove data that we supposedly can't hear. When you burn them to a CD it simply decodes the MP3 file into a WAV that goes on the CD. It doesn't make any difference whether you burn them to a CD and record from that to another CD or just burn them directly to a CD along with the "real" songs.

The levels will be the same. Here is a comparison of the same recording in both WAV and MP3 form.



As you can see, the waveforms look virtually identical.

I think you're confusing what I'm asking -- I appreciate the explanation regarding MP3s and their compression techniques/clarification of my understanding regarding all this; however, while I now understand that a bit better (as far as what's "thrown out" with MP3s etc.) what I was actually asking was, why don't MP3s that are going from a download site online to a folder on a desktop, and then, subsequently, to a blank CD-R/RW, need to be "level adjusted" by the burning program (such as in my case CDBurnerXP), like a real audio recording would? Are all MP3s "at the same level" already in terms of frequency output and they're just converted to the .WAV format? And in that instance, why are .WAV files just like CD tracks -- what makes the conversion so much like audio CD?

I think what you provided in that image of the waveforms is what you're trying to answer my questions with -- so forgive me if that was your intention; perhaps we are getting closer to an explanation or understanding one another then. I think you're saying:

It doesn't matter whether I burn the tracks onto a CD-R/RW ON MY COMPUTER off of MP3 files, or if I first burn them that way, then take that disc and burn those songs OFF THAT SAME DISC onto another CD-R/RW in my RECORDER...the levels will be the same...correct?

If so, I understand that -- I just don't understand why MP3 files don't need some kind of "level adjustment" as they're being burned onto a CD-R disc...are their "levels" the same as a CD track...is that what you're saying?

In other words, let me put it this way: When doing ordinary recording, we adjust/set the recorder's levels for analog input or digital input, depending on the recorder's capabilities (my TASCAM allows for digital adjustments of recording levels in dB steps)...but when I burn an MP3 to CD-R, the burner program just drags the files over to folder and burns them onto the disc, without needing to adjust any of the tracks' audio levels...

Why is this?

 

[TLS Guy]

You are copying the file unmodified, so the level will not change without an intervention.

 

[3db]

When I have approximatel;y 4Gigs of MP3s, I burn them as a data disc to a DVD. I used to burn songs I wanted to hear in the car as audio CDs but thats becuase at that time, the player would only accept audio cd and not Mp3s. Now I burn as MP3s only to a CD-RW. I did reach my limit on one CD-RW.. it saw alot of action and even a complete wipe clean from Nero would not stop from garbling the MP3s. They do wear out too slooooooooooooooowly

 

[BMXTRIX]

I think that if you are looking for level matching across multiple MP3s then you will need another program than what you are using. What I'm not aware of is if this is readily available as, like most others, I just drag my MP3s over in Windows and tell it to make an audio CD, so it just copies from MP3 to WAV format onto a CD for me.

Of course, when the MP3s are originally made by the studio, I would expect that they start with the studio digital master tracks and do a MP3 conversion directly and handle levels just as they do with the CD itself and they would be matched to the CD.

I've seen it before, and it may have been in my Nero software where it can auto level audio, and I believe this can occur both on importing music from a CD as well as outputting to a CD... Just never used it myself.

I think the danger is that a CD or MP3 if properly made are going to have levels which were studio calibrated for best audio quality, while any fiddling done by the end user may be possible, it likely is not ideal to maintain the full range and levels as was mastered by the studio. I certainly wouldn't want to mess with the levels when making any discs from the MP3s I have. Of course, I alos just use native MP3s in my car burned onto CD as data files. I expect my next head unit will just have a USB slot for a flash drive.

 

[PearlcorderS701]

When I have approximatel;y 4Gigs of MP3s, I burn them as a data disc to a DVD. I used to burn songs I wanted to hear in the car as audio CDs but thats becuase at that time, the player would only accept audio cd and not Mp3s. Now I burn as MP3s only to a CD-RW. I did reach my limit on one CD-RW.. it saw alot of action and even a complete wipe clean from Nero would not stop from garbling the MP3s. They do wear out too slooooooooooooooowly

dB,

Hello and thanks. I, too, have the option of burning a CD-R or CD-RW as a DATA disc or an AUDIO disc when I use CD Burner XP in my computer; I always choose AUDIO disc, so they can play back as a normal audio CD in my car, but I did experiment with burning them as MP3 files and my car player didn't react well to them, not allowing certain tracks to be played and such...

But what is the difference between these two methods -- why do you burn MP3s as MP3 DATA files to CD-RWs? Is this because of space -- you can get tremendously longer room for music when burning MP3 files, is that it?

Still, I'm a bit confused with regard to the LEVELS of MP3 files and why they're not "adjustable" as if you're recording on a standalone CD recorder -- in other words, when I drag and drop MP3 files from my computer's desktop into the CD Burner XP program to make a CD-R or CD-RW, the files are simply dragged and dropped, and that's it...there's no need to "adjust" any of the songs' "levels" like you would on a recording device...and I'm wondering why this is...

 

[PearlcorderS701]

I think that if you are looking for level matching across multiple MP3s then you will need another program than what you are using. What I'm not aware of is if this is readily available as, like most others, I just drag my MP3s over in Windows and tell it to make an audio CD, so it just copies from MP3 to WAV format onto a CD for me.

Of course, when the MP3s are originally made by the studio, I would expect that they start with the studio digital master tracks and do a MP3 conversion directly and handle levels just as they do with the CD itself and they would be matched to the CD.

I've seen it before, and it may have been in my Nero software where it can auto level audio, and I believe this can occur both on importing music from a CD as well as outputting to a CD... Just never used it myself.

I think the danger is that a CD or MP3 if properly made are going to have levels which were studio calibrated for best audio quality, while any fiddling done by the end user may be possible, it likely is not ideal to maintain the full range and levels as was mastered by the studio. I certainly wouldn't want to mess with the levels when making any discs from the MP3s I have. Of course, I alos just use native MP3s in my car burned onto CD as data files. I expect my next head unit will just have a USB slot for a flash drive.

Hi BMX,

Thanks so much for the reply -- I think we're getting closer to answering some of my queries about this...

First of all:

I think that if you are looking for level matching across multiple MP3s then you will need another program than what you are using. What I'm not aware of is if this is readily available as, like most others, I just drag my MP3s over in Windows and tell it to make an audio CD, so it just copies from MP3 to WAV format onto a CD for me.

Right -- which is what I do with the aforementioned CD Burner XP program on my computer, that is, drag the MP3 files from a desktop folder into the program and then hit "burn" and create an audio CD. However, a couple of things about this bother me. First of all, why is a .WAV file identified to be the same as an audio CD signal -- why do these programs "convert" the MP3 to .WAV?

Then, there's this that bothered me as well:

Of course, when the MP3s are originally made by the studio, I would expect that they start with the studio digital master tracks and do a MP3 conversion directly and handle levels just as they do with the CD itself and they would be matched to the CD.

Let's start with MP3s and how they are "made" -- where do these files you find online for whatever song you're looking for come from originally? I mean, who puts out all these free downloads, which are everywhere? Honestly, I can find every single song I have been searching for and couldn't find on CD or CD single on some site offering a free MP3 download...but who creates these things? You say they're from a "studio"...but what does this mean? A music label is actually putting these files out there to be shared? And these MP3 files are created by these labels or studios with the original CD master levels attached to them? That's probably why we can't alter or adjust the levels when dragging them from file to file...

Why is it, then, that there are some discrepencies between MP3 audio levels from file to file -- some of the tracks sound like CD, and others I have found to sound terrible and muddled...

I think the danger is that a CD or MP3 if properly made are going to have levels which were studio calibrated for best audio quality, while any fiddling done by the end user may be possible, it likely is not ideal to maintain the full range and levels as was mastered by the studio. I certainly wouldn't want to mess with the levels when making any discs from the MP3s I have. Of course, I alos just use native MP3s in my car burned onto CD as data files. I expect my next head unit will just have a USB slot for a flash drive.

Well, there's some truth here but we must analyze this further -- of course, I know what you mean by "not ideal to maintain the full range and levels as was mastered by the studio" as when I do my recordings on my CD recorder, and if they're digital-to-digital dubs (CD to CD-R), I never alter any recording levels. The recorder is set to take the original levels of the CD I'm coming off of, and copy that exactly (in my TASCAM recorder, there's an option for controlling digital levels, something my former Marantz didn't have, but I always keep this at "0.0dB" which the manual claims retains the original recording's dynamic range) -- however, with ANALOG sources, this is something different...in that case, levels must be controlled with the recorder's left/right channel adjusters.

Still, it's not that I'd want to "mess" with the engineered levels within the MP3 files, it's just that I don't know why we can't alter these levels at all when burning from MP3 to a CD-R/RW; are the songs we're hearing listening to computer generated files like this simply the "max engineered" versions, with dynamically prepared levels? What exactly are we hearing when we listen to MP3 files of music?

 

[TLS Guy]

Right -- which is what I do with the aforementioned CD Burner XP program on my computer, that is, drag the MP3 files from a desktop folder into the program and then hit "burn" and create an audio CD. However, a couple of things about this bother me. First of all, why is a .WAV file identified to be the same as an audio CD signal -- why do these programs "convert" the MP3 to .WAV?

A WAV file is an audio file format of windows. They can be created at varying sampling and bit rates. They can also be compressed to lossy formats such as mp3.

An audio CD has to be produced to the Philips/Sony Red Book standard. The WAV files must be 44.1 kHz sampling rate with a bit rate of 16. The audio bit rate is 1411.2 kbit/sec. There has to be a linked cue file that shows track data etc and information for pauses.

When you rip CD tracks and convert to mp3 you are converting the WAV files to lossy mp3 WAV files at a specified streaming rate supported by the format. For mp3, streaming rates from 20 to 320 kb/s are available. So even at the maximum supported bit rate of mp3 you can see a lot of data is lost.

When you convert back to CD you convert back to CD standard 44.1/16, but you do not recapture the lost data, so quality is not improved.

Let's start with MP3s and how they are "made" -- where do these files you find online for whatever song you're looking for come from originally? I mean, who puts out all these free downloads, which are everywhere? Honestly, I can find every single song I have been searching for and couldn't find on CD or CD single on some site offering a free MP3 download...but who creates these things? You say they're from a "studio"...but what does this mean? A music label is actually putting these files out there to be shared? And these MP3 files are created by these labels or studios with the original CD master levels attached to them? That's probably why we can't alter or adjust the levels when dragging them from file to file...

Why is it, then, that there are some discrepencies between MP3 audio levels from file to file -- some of the tracks sound like CD, and others I have found to sound terrible and muddled...

Now you have asked how recordings are made.

For pop music each microphone is laid down as a separate track usually.

For stereo these tracks are mixed down to two track. This is done with complex programs like ProTools or WaveLab. I use Wavelab 6

Now all these tracks are usually laid down as WAV files at 96 kHz 24 bit.

The master mix is usually at this rate. During mix, effects such as echo etc can be added via plugins.

The next step is mastering. At this stage any overall Eq is added, dynamic range compression or expansion, fades/cross fades and the overall level of the CD set. All of these programs contain extensive metering including a bit meter. You never want to run out of bits! You try and set the peak level to use most of the bits available to get optimal dynamic range. Optimal dithering is also part of this process.

Next the files are converted in batch to 44.1/16 bit.

The next step is CD compilation. Here the tracks (individual WAV files) are added to the compiler. Then the pauses between tracks are set, zero to whatever you want.

Now you are ready to test the production for CD and if OK you can burn your first CD.

Now you can make mp3 files WAV files by batch conversion or individually. You can also convert to any other codec, FLAC, WMA, OGG, ACS, Lucent etc.

Let's start with MP3s and how they are "made" -- where do these files you find online for whatever song you're looking for come from originally? I mean, who puts out all these free downloads, which are everywhere? Honestly, I can find every single song I have been searching for and couldn't find on CD or CD single on some site offering a free MP3 download...but who creates these things? You say they're from a "studio"...but what does this mean? A music label is actually putting these files out there to be shared? And these MP3 files are created by these labels or studios with the original CD master levels attached to them? That's probably why we can't alter or adjust the levels when dragging them from file to file...

Why is it, then, that there are some discrepencies between MP3 audio levels from file to file -- some of the tracks sound like CD, and others I have found to sound terrible and muddled...

As stated above mp3 files are made by conversion from uncompressed WAV files. They can be converted at low rares 20 kb/s up to 320 kb/s for mp3 but higher for other lossy codecs like AC3. Also there are loss less codes like FLAC and WMA. All lossy codecs are not created equal and the ubiquitous mp3 is the worst sounding of all of them and has now been abandoned by the BBC in favor of AC3. The lower the bit rate the worse it sounds, the higher the better. Loss less formats like FLAC when reconstituted are identical with the original. You can down load 96kHz/24 bit FLAC files from sites like HD tracks.

So the bit rate is the chief reason for quality difference between mp3 files. Personally I hate all lossy formats, and fail to understand why people seem to think they sound like CDs

Now the level is set in the mastering process, and if you do a conversion the levels will not change.

There are programs that will let you change the level of a file and the dynamics. WaveLab does for instance. It is not generally a good thing for the general public to do. You have to know what you are doing. You need to be able to create a peak file for analysis and have a bit meter, so you don't run out of bits. If you run out of bits, it is not graceful overload like analog, but loud pops and cracks that can spell death to a speaker.

When editing WAV files, mastering and compiling CDs it is a good idea to have to screens or a divided wide screen, like this.

The left screen has an open WAV file and the commands for WaveLab. The right screen contains the faders for the mixer/DAC which is an RME Fireface 800. Round the edge of the mix screen is the metering for WaveLab.

So it is a complicated business with a big learning curve.

Now when any audio files are made available for download, they have to be up loaded to a server. This can be done by the original producer or owner of the material. It is also often done illegally by people ripping WAV files from CD
and converting them. Then the files are uploaded to a server. For my purposes I rent space on a service called Strongspace.

Now for classical productions it is important to properly synchronize the cue file. This is very important as often there must be no pause between tracks and certainly no artifacts. About five years ago as was approached by some UK labels to solve this problem. My sons and I went to work on it and solved it. The first exact downloadable CD image was sent from this studio.

A lot of outfits still don't have the hang of it. Most downloads from HD tracks I have to remaster. I also bought a download from the Minnesota orchestra and had to remaster that also. So it seems most people have not got the hang of it still.

 

[BMXTRIX]

However, a couple of things about this bother me. First of all, why is a .WAV file identified to be the same as an audio CD signal -- why do these programs "convert" the MP3 to .WAV?

.wav files - at 44.1kHz is the standard uncompressed format on a CD. While a CD doesn't use .wav files exactly, it does use PCM 44.1kHz files, which are, for all intents and purposes, identical to a .wav file at 44.1kHz in PCM format.

The ORIGINAL .mp3 file is not a 44.1kHz PCM file, but is a .mp3 file at whatever compression it was originally created at. (more on that in a second). So, to get it to a standard CD, as described in the post above, it must first be converted to a 44.1kHz PCM encoded .wav file. The simplest point is that Microsoft Windows plays very nicely with .wav files and 44.1kHz and PCM encoding to give you a nice CD.

BUT! The original source file matters a great deal!!!

So...

Let's start with MP3s and how they are "made" -- where do these files you find online for whatever song you're looking for come from originally?

It depends entirely on where you are getting them. From iTunes or Amazon, almost all that music comes from the studios and is made, as described in the prior post, using professional encoding software from studio master files recorded from the artists. They are above CD quality originals which are being downgraded, using top shelf software, before being sold on those websites.

But, there are hundreds of non-pay sites which have .mp3 files. Those come from everywhere and everything. Windows has an audio recorder which can take a line in feed from your home stereo and convert it to a MP3. Just plug a radio or cable box in, record some audio, save it as a .mp3 file. Viola! You have a .mp3 of a song from the radio!

I mean, who puts out all these free downloads, which are everywhere? Honestly, I can find every single song I have been searching for and couldn't find on CD or CD single on some site offering a free MP3 download...but who creates these things?

From REPUTABLE sites (iTunes, Amazon, etc.) where you pay for the song, it's almost always from a studio. But, anyone and everyone is putting their stuff, which often belongs to others, out there.

There are some really LOUSY programs which are out there as well which serious degrade the original .wav file in the conversion to a .mp3 file. Some people record a 64kbs while others record a 320kbs for their .mp3s.

You say they're from a "studio"...but what does this mean? A music label is actually putting these files out there to be shared? And these MP3 files are created by these labels or studios with the original CD master levels attached to them? That's probably why we can't alter or adjust the levels when dragging them from file to file...

Almost no studios put music out there for free. A few have a few songs which may become available, and you may find that those .mp3 songs are not at very high quality. Sometimes even less than 64kbs in quality. But, if you are finding lots of 'free' music, then you may not be looking on a legal website. Downloading content which is not yours, is not paid for, and the artists have not authorized for distribution is illegal. While it may be readily availble, it is impossible to know the actual quality of the source.

Most often: People download from iTunes/Amazon and just put it out there for anyone to get. It's completely illegal.

Sometimes: People take their old record albums or tapes and hook it up to their computer and record it into their computer, then make .mp3 files to share.

I know I've got a couple of albums I've captured to my PC for playback... quality was terrible.

Why is it, then, that there are some discrepencies between MP3 audio levels from file to file -- some of the tracks sound like CD, and others I have found to sound terrible and muddled...

The above really states the why. Because it may not have come from a studio, and you really don't know where it came from, how it was captured, or if was properly done at all.

...however, with ANALOG sources, this is something different...in that case, levels must be controlled with the recorder's left/right channel adjusters.

Still, with this you shoot for 0dB as the standard. In theory, even if someone does capture from an analog source, as long as it is a good analog source, and they have full dynamic range, and 0dB as their baseline, then you should see a good .mp3. This is easier said than done.

Still, it's not that I'd want to "mess" with the engineered levels within the MP3 files, it's just that I don't know why we can't alter these levels at all when burning from MP3 to a CD-R/RW; are the songs we're hearing listening to computer generated files like this simply the "max engineered" versions, with dynamically prepared levels? What exactly are we hearing when we listen to MP3 files of music?

The above pretty much explains it. The reason you can't mess with the files is that CD burning happens faster than real time. So, you can definitely edit the levels, pitch, tone, balance, etc. of any .mp3 file by getting audio editing software. You don't have to get an all out program like the one described above, but you can pick up any number of (thousands?) programs which can do audio manipulation.

There may even be some which operate in-line with burning software. But, more likely, you will bring in a .mp3 track and edit the levels, then save it out as a different .mp3 track or as a .wav file. You have endless possibilities, but most likely NOT with the software you are using.

 

[BMXTRIX]

Gotta add this:

http://www.freedownloadscenter.com/Best/mp3-auto-volume.html

http://boards.straightdope.com/sdmb/archive/index.php/t-455872.html

I also just looked at my Nero software and it includes a 'normalizing' plug-in which is what you are talking about doing - getting all the levels in line with each other. Computers can do this automatically pretty darn easily.

 

[PearlcorderS701]

Wow -- lots of good info here, BMX! Let me chew on this and get back to you; thanks for doing the research for those links, too...

 

[PearlcorderS701]

.wav files - at 44.1kHz is the standard uncompressed format on a CD. While a CD doesn't use .wav files exactly, it does use PCM 44.1kHz files, which are, for all intents and purposes, identical to a .wav file at 44.1kHz in PCM format.

I see...

The ORIGINAL .mp3 file is not a 44.1kHz PCM file, but is a .mp3 file at whatever compression it was originally created at. (more on that in a second). So, to get it to a standard CD, as described in the post above, it must first be converted to a 44.1kHz PCM encoded .wav file. The simplest point is that Microsoft Windows plays very nicely with .wav files and 44.1kHz and PCM encoding to give you a nice CD.

BUT! The original source file matters a great deal!!!

I think I see...

So...

It depends entirely on where you are getting them. From iTunes or Amazon, almost all that music comes from the studios and is made, as described in the prior post, using professional encoding software from studio master files recorded from the artists. They are above CD quality originals which are being downgraded, using top shelf software, before being sold on those websites.

But, there are hundreds of non-pay sites which have .mp3 files. Those come from everywhere and everything. Windows has an audio recorder which can take a line in feed from your home stereo and convert it to a MP3. Just plug a radio or cable box in, record some audio, save it as a .mp3 file. Viola! You have a .mp3 of a song from the radio!


From REPUTABLE sites (iTunes, Amazon, etc.) where you pay for the song, it's almost always from a studio. But, anyone and everyone is putting their stuff, which often belongs to others, out there.

There are some really LOUSY programs which are out there as well which serious degrade the original .wav file in the conversion to a .mp3 file. Some people record a 64kbs while others record a 320kbs for their .mp3s.


Almost no studios put music out there for free. A few have a few songs which may become available, and you may find that those .mp3 songs are not at very high quality. Sometimes even less than 64kbs in quality. But, if you are finding lots of 'free' music, then you may not be looking on a legal website. Downloading content which is not yours, is not paid for, and the artists have not authorized for distribution is illegal. While it may be readily availble, it is impossible to know the actual quality of the source.

Most often: People download from iTunes/Amazon and just put it out there for anyone to get. It's completely illegal.

Sometimes: People take their old record albums or tapes and hook it up to their computer and record it into their computer, then make .mp3 files to share.

I know I've got a couple of albums I've captured to my PC for playback... quality was terrible.

I've gotten some files from somewhere called "zippyshare" and the sound quality seems to be fine upon playback, save for a John Mayer track that didn't sound all that good -- no matter the site I got it off of...

But while I understand what you're saying about the quality discrepencies, I don't see how there could be files just created by people "hanging around" out there; I mean, do people just make copies of songs and post them places online? Is that what you're saying? And original MP3s, sanctioned by the recording studios, are also made available via the pay sites and such?

What I'm most concerned with is why MP3s are just "as-is" in terms of output quality when we burn them from a file to a folder and then to a recordable CD...is it, essentially, just because they're "data" that's being transferred around? I suppose that gets me to your explanation of the recording alteration software, which you get to later on...

The above really states the why. Because it may not have come from a studio, and you really don't know where it came from, how it was captured, or if was properly done at all.

Okay...

Still, with this you shoot for 0dB as the standard. In theory, even if someone does capture from an analog source, as long as it is a good analog source, and they have full dynamic range, and 0dB as their baseline, then you should see a good .mp3. This is easier said than done.

Yes, I understand that -- and I do shoot for 0dB when doing analog recordings from vinyl, etc. -- I was just explaining how when doing digital dubs, it's normally just digital-to-digital (CD-to-CDR) and with analog there is an opportunity to adjust the signal (although with more modern recorders, like my TASCAM, the user can adjust the digital level as well, beyond or under the 0.0dB threshold)...

The above pretty much explains it. The reason you can't mess with the files is that CD burning happens faster than real time. So, you can definitely edit the levels, pitch, tone, balance, etc. of any .mp3 file by getting audio editing software. You don't have to get an all out program like the one described above, but you can pick up any number of (thousands?) programs which can do audio manipulation.

There may even be some which operate in-line with burning software. But, more likely, you will bring in a .mp3 track and edit the levels, then save it out as a different .mp3 track or as a .wav file. You have endless possibilities, but most likely NOT with the software you are using.

I think I see; but if I stay with what I'm using and doing now -- that is, the CD Burner XP program -- and I burn MP3 files to CD-R and finalize them as AUDIO CDs at the end, that means I'm hearing, upon playback, the actual raw quality of the MP3 file...and however it was "done" or "mastered" depending on the source?

 

[PearlcorderS701]

Gotta add this:

http://www.freedownloadscenter.com/Best/mp3-auto-volume.html

http://boards.straightdope.com/sdmb/archive/index.php/t-455872.html

I also just looked at my Nero software and it includes a 'normalizing' plug-in which is what you are talking about doing - getting all the levels in line with each other. Computers can do this automatically pretty darn easily.

Well, I wasn't really looking to normalize levels between MP3 tracks -- what I was talking about more was why when we burn MP3s do they just burn "as is" without needing any manipulation of levels or signal; and what we're actually hearing when playing these files back on a CD-R...

 

[dkane360]

Well, I wasn't really looking to normalize levels between MP3 tracks -- what I was talking about more was why when we burn MP3s do they just burn "as is" without needing any manipulation of levels or signal; and what we're actually hearing when playing these files back on a CD-R...

You don't need to manipulate levels because they're already mastered. It would make no sense to have to manipulate the signal yourself. The lossy or lossless downloads you get on the internet (from legitimate sources) are just duplicates/copies more or less of the studio master.

When you burn flac to a cd-r, it should sound exactly the same as a normal cd (unless a compressed file is put into a flac container). If you burn a 128kbps mp3 to a cd, it'll sound like a 128kbps mp3

 

[MDS]

Recording and digital audio extraction (aka 'ripping') are different processes.

When you extract audio from a CD, you get audio that has already been recorded (and the levels set initially by whomever did the recording), mixed, and mastered. If you then just burn that data to a CD-R you don't have to set any levels because they are already set. You're not 'recording' anything - you're extracting the PCM from one CD, and then burning that to a CD-R.

Now if the audio on the CD you use for the source is not 'hot' enough, say it's an older CD where the levels are much lower, you can do whatever you want to it before burning it to a CD-R if you use an audio editor and learn how to use it properly. To do so, you rip the audio you want from the source CD and save it as a WAV file or better yet use the audio editor to do the ripping and it will have the raw PCM samples in memory without having to save an intermediate WAV file. A WAV file is just a header with information about number of channels, sampling frequency, bit depth, etc followed by the raw PCM samples that are the music.

Make whatever changes you want, such as normalizing or compressing (dynamic compression, not lossy compression like .mp3) to make it louder, save it as a WAV file and then burn that WAV to a CD-R. If you're creating an audio CD, the PCM samples from the WAV file will get placed on the CD-R according to the Redbook audio CD specification and it will play in any CD player.

If you intend to make an audio CD there is no point in encoding the WAV to .mp3 and then burning the .mp3. The .mp3 will be decoded to PCM but it is no longer the same as the original from the source CD because the encoding process removes part of the audio that its model thinks you wouldn't hear anyway. If you want .mp3 then burn a data disc - you can get well over a hundred songs on one CD and as long as you have a player that recognizes it is a data CD with .mp3 format files on it, it can read the file, decode it, and play it.

 

[PearlcorderS701]

You don't need to manipulate levels because they're already mastered. It would make no sense to have to manipulate the signal yourself. The lossy or lossless downloads you get on the internet (from legitimate sources) are just duplicates/copies more or less of the studio master.

When you burn flac to a cd-r, it should sound exactly the same as a normal cd (unless a compressed file is put into a flac container). If you burn a 128kbps mp3 to a cd, it'll sound like a 128kbps mp3

I understand -- but what I'm saying is, when using a standalone, external burning system like a CD recorder, the end user HAS THE OPTION to "manipulate" recording levels if he or she wants to, even if it's from a "studio's master" CD or so forth; I was wondering why this isn't possible, or even available, when doing it via computer files...but from what I understand based on what BMX was saying, there is some software which allows this...

Are you essentially saying the MP3 files I'm downloading and burning could/should be "left alone" and dropped onto a CD-R as-is, as they're already the studio's master versions?

 

[dkane360]

Are you essentially saying the MP3 files I'm downloading and burning could/should be "left alone" and dropped onto a CD-R as-is, as they're already the studio's master versions?

If you drop them into a cd as they are and you burn them as mp3 files, it will be an mp3 cd, so only cd players that say that can play mp3 cd's will be able to play it. You should not ever need to adjust the levels on a song unless, as someone mentioned earlier, its too quiet. I've never felt the need to adjust levels on any song, except for the occasional quiet classical cd rip. Even then, it's just a minor volume adjustment.

 

[PearlcorderS701]

If you drop them into a cd as they are and you burn them as mp3 files, it will be an mp3 cd, so only cd players that say that can play mp3 cd's will be able to play it.

Yes, I realize that if a disc, or files, are saved as "MP3 files," and burned to a CD-R, then only CD players that say they can play MP3 discs will be able to play them -- I experimented with this already, when I first burned my downloaded music tracks onto a CD-R but as DATA files (MP3) and tried playing the CD-R in both my car and home two channel system. Both players are able to play MP3 discs, but both my Marantz CC4001 home changer and my JBL car changer gave me problems with these types of burns -- the home changer took forever to recognize the disc in the tray with MP3 files (I know for a fact that the changer does play MP3 encoded discs; beyond just saying so on the aluminum front panel) and in the car, strange things happened, as I couldn't play any tracks after the first one even after the disc had been finalized properly. It would only play the first track burned, and then lock up.

I have since burned Internet-sourced tracks as AUDIO discs instead, but this leads me to ask...what's the difference between burning a CD-R with MP3 files as a DATA disc or an AUDIO disc? My computer's CD Burner XP program asks you to choose this when you first launch the program -- it asks BURN DATA CD or BURN AUDIO CD, but what would be the difference in doing MP3-to-CDR burns?

You should not ever need to adjust the levels on a song unless, as someone mentioned earlier, its too quiet. I've never felt the need to adjust levels on any song, except for the occasional quiet classical cd rip. Even then, it's just a minor volume adjustment.

I understand this -- and I never do; but what I'm saying is, my pro CD recorder has the option and ability to adjust digital recording levels (which my previous consumer-grade Marantz didn't) and yet when burning MP3 files to a desktop folder and then to a CD-R via a computer, there's no way to "manipulate" these levels of an MP3...I was just wondering what we're actually HEARING when burning an MP3 file to CD-R/RW being that these files can't be adjusted without the proper software...