Intro:
Well, with my recent acquisition of an mp3/CD player I guess it’s official - I’ve finally joined the “21st Century” when it comes to music! Sure, I’ve collected mp3s since about 1999 and have my share of “burned” music CD’s. But all the new music technology seemed a little daunting to me. I really didn’t know a bit-torrent from a FLAC or a bitrate from an ipod. Also, I’ve finally upgraded by computer and now have the capability to create some nifty sound files with my computer. But I really wasn’t sure how to go about converting some of my vinyl albums and concert cassettes to mp3 files.

I figured that I wasn’t the only one in this quandary, so I contacted recording engineer Mark Spano (the creator of “Mok’s Smile”) to answer a few of my questions regarding this ever-growing technology.

Mark patiently answered the many questions that this technically-challenged computerized music novice had! Hopefully, his answers will be helpful to a few EAR CANDY readers, who might have been like me – “having the technology”, but not the know-how. Excuse me now…I have a couple hundred albums and live shows to burn to mp3s!

MP3/SOUND FILE BASICS

E.C.: I have a question regarding the various formats of sound files that are out there. What is the difference between mp3 and wav files (other than the obvious that wav files take up a lot more space)? Is the mp3 format the best format to "archive" your sound files?

Mok: There are many file formats is current use for storing audio. It all boils down to two things: bandwidth and dynamic range. CD audio is generally considered of a good enough quality to be a standard, so we'll work down from that. CD audio has great bandwidth and great dynamic range capability (signal-to-noise ratio). It's got a bandwidth of 20Hz to 20,000Hz – roughly the discernable hearing range of the human being. The dynamic range capability is 96dB. What that all means is that music encoded on a CD should be very high quality. This is generally referred to as 'uncompressed' audio (in the data world). Uncompressed audio can be stored in several formats, all of which are pretty much equal. They are WAV, AIFF, and SD2. WAV is primarily a Windows format, although it is recently considered universal.

AIFF is Macintosh native. SD2 is native to Pro Tools recording software and generally not useful outside of that software. You control the amount of bandwidth and dynamic range in these formats by setting the sampling frequency and bit depth. CD audio in WAV or AIFF format is 16 bit / 44.1kHz audio. That means that the 16 bits of dynamic information (volume), which is actually 32,768 values of resolution, is 'sampled' 44,100 times per second. The amount of data this takes up is about 10 MB per stereo minute. It's a pretty good representation of the original actual analog audio waveform. But, it's an internet bandwidth hog, when sharing. A five minute song is about 50 megabytes - that would take the average user on a 56k modem about two and a half hours to download one song! That is one of the reasons why MP3 was invented. The Moving Picture Experts Group (MPEG, for short) are the folks who have come up with many variations of how to compress video and audio.

MP3 is the third type of audio compression they came up with, and it works pretty well. It takes that 10 MB/minute file and knocks it down to about 1 MB/minute, using what they call psychoacoustical filtering. This is a process that eliminates audio information based on what it thinks is information you can't hear whether it's there or not. It's more complex than that, but suffice it say that MP3 thinks 9 out of every 10 bits of audio information in a song is stuff you don't need to get the point across, so boom, it's gone. Now that 5 minute song is 5 MB, and over 56k, that's only 15 minutes. Can you tell the difference? Some can, and don't like what's missing. Some can't, and don't care. If you can't tell the difference, maybe you'd be OK with archiving your CDs and other music in MP3 format - it will take up significantly less space. If it's grating, or you think there will be a better compression format to come, stick with WAV or AIFF, uncompressed. You can always compress the uncompressed - you can never uncompress the compressed.

E.C.: Also, Windows media player can create a wma file from a CD. How do these compare to mp3's?

Mok: WMA is similar to MP3, it's just Microsoft's way of compressing audio. It works about the same, with sometimes similar and sometimes different results. Some songs will compress better in MP3 and others will compress better in WMA. To me, they do just about the same thing.

E.C.: What is the sound quality related to a commercial CD, wav files and mp3's? (I'll get to the subject of bitrate later).

Mok: I think I got it in the previous question, but this may be handy:

• CD - 16 bit/ 44.1kHz (high audio quality)
• WAV / AIFF - depending on the source, it can be down to 8 bit / 11.025kHz (phone quality) up to 24 bit / 192kHz (extremely high audiophile level quality)
• MP3 - bit rates determine quality, but about one-tenth the quality of CD

E.C.: When "burning" a sound CD, does it make a difference if you are using mp3 or wav files?

Mok: As always, the destination file will be representative of the source. So if it's compressed and you're burning a CD, the CD will sound like the MP3. If you start with a higher quality source, you'll end up with a higher quality disc.

E.C.: What about converting between wav's to mp3s then back to wavs'? Is there a sound loss?

Mok: Once the 9 pieces are taken out of the 10, leaving 1 (MP3), those 9 pieces cannot be recovered back into the WAV. It's like making a VHS copy of a DVD and then making a DVD copy of that VHS - it's going to look like a VHS still.

E.C.: What about RA (real audio) files? How do I create these from mp3's? Or how do I create mp3's from RA files?

Mok: Real audio files (RA) are encoded by the Real software codec. Some of their products allow encoding to RA format. They invented their format before MPEG came out with MP3, so it's hard to say which sounds better. Either way, nowadays, MP3 is much more universal and does not require proprietary software to play.

E.C.: How do you create RA files for websites (from other existing audio files)?

Mok: Usually RA files can be created with a product from Real Software, or one that has a license from Real Software, like Pro Tools. It works similar to an MP3 encoder, with similar tradeoffs.

E.C.: Also, what is the best FREE program to use for this?

Mok: I remember using one from Real called RealProducer, but that was years ago. I don't really know about it now - been using Pro Tools for a few years...

CDR BASICS

E.C.: I've got a CD-burner and want to create some CD-audio discs. How do I "make" mp3's from commercial discs? What is the difference between "ripping" and "encoding"?

Mok: First, if you want to make CDs from other CDs, you don't need to make them into MP3 first - most CD burning programs allow digital audio extraction into WAV or AIFF format so that no quality is lost in the process. I would suggest this method as it's not harder and definitely faster that ripping to MP3 (and sounds better!). If you want to make MP3 files from a CD, then 'ripping' is the step you need. This is a term that basically means digital audio extraction from CD and encoding to MP3, all in one step. This is very useful for fast MP3 encoding from CD for transfer to portable MP3 players and/or internet friends.

E.C.: What are the best FREE programs on the web for these two procedures?

Mok: The best digital audio extractor for Mac is the Quicktime Player. The best digital audio extractor for PC is Exact Audio Copy. The best ripper and encoder (in my opinion) for both platforms is ITunes.

E.C.: Are there any reasonably-priced programs for doing this that you can recommend?

Mok: Pro Tools can do all of this, but it's usually expensive. Because of the prevalence of the technology, there's almost no reason to buy a ripper or encoder.

E.C.: When creating an mp3, how important is bitrate? What exactly IS bitrate? Is it the only factor that you should think about when creating an mp3? What should you pay special attention to when creating mp3's?

Mok: In MP3 land, bitrate determines both sound quality and file size. The MP3 spec allows for bitrates from 64kbps up to 320kbps. The higher the bitrate, the larger the file. A 320kbps stereo MP3 will be twice as large as a 160kbps stereo MP3, but sound a bit better. How much better is subjective. Generally, bitrate is the most deciding factor in making MP3s. It is a sacrifice scenario - better sound, bigger file / smaller file, worse sound. You can, on some encoders, change the bitrate from a constant one to a variable one. Variable bitrate encoding (VBR) generally makes a better sounding MP3 (by varying the bitrate over the length of the file, it can slow down over less complex material and speed up over more complex material, giving more bandwidth to where it's needed), but isn't always compatible with all players.

Other than that, always make sure you're encoding a high quality source. If you try encoding a file that's already been encoded to MP3, it's like if the original had 100 pieces and you took 90 out, then took another 9 from that. One one-hundredth of the information really isn't going to be representative of the original 100.

E.C.: I've got some vinyl records and cassettes that I want to convert to mp3 - does it make a difference if I use a direct line from a walkman or a component stereo system?

Mok: No, it shouldn't, but there are a few things to consider. For cassettes, play out of a line output into your PC's line input. If your walkman only has a headphone out, it may overload the PC input. Try to use only matched ins and outs - line to line. Records are a different story. All records post 1940-something are pressed with a pre-equalization curve called the RIAA frequency curve. The RIAA came up with a way to get more and louder audio onto a disc by rolling off a lot of low end below 500Hz and boosting the high end above 6kHz before cutting. Therefore, in order to play it back and reproduce it properly, the output of the needle needs to have the inverse EQ applied (boost low end, cut high end). This EQ is built in to all Phono Preamps. So, in order to record the output of a phonograph into a PC, it needs to go through a phono preamp first. There are a few interfaces for PC that have a phono preamp option built in for this application. Otherwise, just hook up the phonograph to your receiver's phono input (the receiver's built in phono preamp) and take a tape output from the receiver (which is a line level output) and connect to the PC line input.

E.C.: There used to be that rumor that CDR's degrade after 10 years. I try to make multiple backup copies of all my sound files. Just how often to CDR's last?

Mok: No one knows yet. Some people have CDRs that old, but it is widely regarded as a relatively stable medium, with a lifespan of 5 to 100 years. What that means is you should try to back up your CDRs about every 5 years or so. That would be safe. I think.

BIT TORRENT BASICS

E.C.: The newest trend is bit torrents. What are these and how do they work?

Mok: Torrent is an amazing way to share files. It takes a large file and splits it up into small pieces. Then the pieces are shared (seeded) to downloaders (peers) not in any order. Since all of the seeds and peers are in communication with each other, each can share their pieces with each other - by the time the seeder has put out one full copy of his file, there can be thousands of peers with nearly full copies (instead of just a 1:1 ratio like Limewire/Kazaa/etc. filesharing). Extremely efficient and spreading like wildfire, torrent now consumes one third of total internet bandwidth worldwide.

E.C.: What is a FLAC file?

Mok: FLAC is short for Free Lossless Audio Compression. It compresses audio at about a 2:1 rate, which isn't that big a deal, but it is completely uncompressable back to its original form, making it lossless. Very useful for trading uncompressed audio (generally over torrent) without worrying about taking up unnecessary bandwidth.

E.C.: What special programs do you need to use bit torrents?

Mok: All you need is a bit-torrent client and some bandwidth. The preferred client is called Azureus. It is the most easily configurable and widely spread client out there. You launch it, and then grab a torrent file from a torrent site and start sharing. Or create your own torrents, if you have a place to share them from. Easytree is my favorite torrent site - non-commercially-released material from commercial artists is easily shared there. I have downloaded over 200 CDs worth of great material from there.

OTHER

E.C.: I hear alot about ipods. What exactly are these and what formats do they use?

Mok: Ipod is a portable music player from Apple. It is compatible with PC as well, and can play MP3, AAC (Apple's proprietary format on sale at the Itunes music store), WAV, and AIFF files. Ipod has huge storage and easy use. They are also very popular for their small size and style. It is easily the best player out there - though competition from Microsoft and Sony are coming up...