Re: More Wave / CD / MP3 Questions
1) Recording onto CD-s, and regarding Waves: I see that saving a file in 24 bit or 32 bit is possible. I would think that is far clearer and more desirable than 16 bit. Yet when I saved a song in 16 bit, 24 bit, and 32 bit, only the 16 bit made it onto the CD. Is there a way to get the higher bitrates onto CD’s, or are they there as a form of fools gold?
Track on audio CD's are not "files" as you are thinking of them. Think more in terms of old LP records, but with pits of 1's and 0's representing your audio. Now you can't just take a 33rpm album and play it at 45 and expect it to sound normal, right? Likewise, even if you could record an audio CD at 32bit, no player would play them! The Audio CD standard is 16bit/44.1khz ... that's what the players want to see and that's what your cd hardware/software wants to burn. Now these numbers weren't just picked out of the blue. According to nyquist, the maximum frequency that can be encoded is going to be equal to half the samplerate. Thus, at 44khz we can encode a frequency up to 22khz, which is just above what humans are able to hear (well, according to biology and mathematics, reality may be different). Working with 16bit samples, the maximum dynamic range is 96db, which leaves plenty of room for noise...plus you get an adequate number of discrete values to represent your waveforms, as long as the mix is hot. PLUS, 16bits is just plain computer friendly...and remember that CD players started coming out in the late 80's when 2 bytes was still something to respect
Of course all the math mumbo jumbo is sorta bullshit when we start taking into account the true depth of how human's relate to sound. Thus we have a new standard of DVD Audio that is 24bit and up to 192khz. But here's the catch, you can't just take your 16/44 file and convert it to 24bit and expect to gain anything. How would the conversion algorithm know what was supposed to be going on down in those lower bits? It doesn't. You have to start at the higher bitrate to see any benefit. That's why we record audio at high bit depths and sample rates, even though we'll eventually just mixdown to CD format, or even make an MP3 for internet distribution.
2) MP3's onto CD’s: When I tried to put an MP3 onto CD, it didn’t work. Can you not transfer MP3's onto CD’s? Or, if I understand your notes, do I need to first convert them to Waves? If that is the case, I assume I shouldn’t be saving them as MP3's at all, unless I’m going to be sending them via Internet.
You can put an MP3 on a data CD as a data file, just like you could any other file. Of course that's not going to play in your CD player (unless it's an MP3 player).
As I said, CD audio has to be in CD audio format. Lots of CD burning software will accept MP3 files, but to actually create the CD, that MP3 is first uncompressed into raw audio data (that for all intents and purposes looks just like a wave file!). You know, even when you're playing an MP3 file it has to be converted into something that your soundcard can understand...and all your soundcard understands is raw sample data...it doesn't care where the data comes from. Most of this work is done on the fly and you never have to see or think about it.
3) Bitrates: I did notice a great difference when I encoded the MP3 with the highest bitrate.
As you should. The MP3 compression scheme keeps only what it thinks is most important to represent the original audio, and throws the rest away. Thus the higher the bitrate, the closer the MP3 will sound to the source.
4) Other CD/Hard drive formats: When I recorded CD’s onto my hard drive, the saved files had“RMJ” extensions (rea.l system media). They sound pretty clear–can these be saved onto CD, or do they need to be converted back to regular Wave’s first? And are they the best format to save CD songs onto HD anyway?
You'll have to be more specific about what you're recording with, as it will determine what formats you're allowed to end up with. You can burn any audio that your CD authoring software will allow - but it must be capable of recognizing the input and converting it to audio cd format. Otherwise, you'll first have to do the conversion to a suitable format (probably wave).
Oh, and if you're talking about data CD's, then it's really no different than saving to a hard drive. Any file on your hard drive can be written to a data CD as long it's under 650MB...and it'll show up on that CD just like it did on the hard drive. It doesn't matter that the data in the file is "audio"...the computer doesn't give a rip about the intent of the file, it's just saving bits. Now there are some minor details about CD file systems that make them not the equivalent of a hard disk, but my point is that data is data. Do not confuse data CD's and audio CD's, they are different beasts sharing the same medium.
The best format to store audio depends on what you want to do with it. If you want to turn your computer into a giant jukebox so you'll have a lot of tunes to listen to while you work around the house, then MP3 format is probably the best, since the quality is ok enough for casual listening, and the file size is trivial by today's standards. If you want to burn audio CD's for critical listening, or if you want to use the audio for recording work, then you want to save it in a raw uncompressed format, like wave. (note, you can use lossless compression schemes like ZIP or monkey audio to reduce the file size by maybe 25-33% for long term storage)
5) Other Internet formats: Aside from MP3's, I notice other formats being used on the Internet, by people with record label money to pay for good quality. Beck has a short piece that is about 500KB in size, with an “ASX” extension. A country artist on AOL this morning has a song that is about 2MB, with an “WMA” extension. And I see MP3's and a few other formats out there. Do you have any comments or preferences regarding those formats?
There are tons of formats anymore. WMA is microsoft's windows media audio, which is a similar standard to MP3 (although not technically "standard"). ASX is some kind of nullsoft streaming MP3 thing. RA and various "R" files are realaudio. Blah blah blah.
The very best of them, hands down, is MP3. Why? Because MP3 has just plain become the standard. Regardless of what platform you're on, or what software you're going to use, chances are that MP3 is going to be acceptable. In terms of sound, a good MP3 encoder can create great sounding files that hold up to or exceed any of the other formats out there. While there will be differences here and there, you just can't go wrong with MP3, so there you have it.
Second best is probably WMA. It sounds ok, and almost every windows PC will have windows media player installed...so the files will at the very least play on all microsoft machines, which is quite the majority. Obviously I give preference to formats that can hit the widest audience with the least amount of rejection or headache.
The very worst of them all is Real Audio. Reason being that a) it sounds like crap for the most part and b) it will only play with realaudio player, and a whole lot of people out there HATE real networks. Real Audio software is intrusive, difficult to download, etc etc. I won't even install it on my systems anymore, I've just had it with that junk. While just about anyone with a computer can play an MP3 file, you're going to run into a lot of people who won't be able to listen to your material if it's in realaudio format. I can not stress enough how much I despise that company and its products.
Slackmaster 2000
