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Create your own Mp3s

The following section is ever so slightly technical. If you are a complete technophobe this page may seem scary. If, on the other hand, you are one of those people who always like to know "how's it done?" then come on in...on second thoughts you technophobes at the back can squeeze in as well, it's honestly not as complicated as you might suspect.

The Fundamental Law of Quilts!

There is a law that must be learned early on in the process of creating MP3s and it goes like this: Low bit rate = High Compression = Small file size. MP3s have become the most popular method of transferring audio files on the internet because of that little law. In the bad old days, before MP3 was invented, an uncompressed digital audio file could be measured in terms of hundreds of megabytes. That same file when turned into an MP3 can be as small as just a few megabytes. This is because MP3 is a technology which compresses the file into a much smaller size. Imagine it like this; a super king size feather quilt. It's huge! but start compressing it, squeezing it down and eventually you can fit it into a pillowcase. It's still the same quilt, it can still be used for the same purpose, it's just in a much smaller form. It's not a perfect analogy but it kind of works like that.

Basically the more compression you use, the smaller the end file size will be. Conversely, the less compression, the larger the file. One way to determine how much compression is applied is done by setting the "bit" rate of an MP3 file before you create it. Remember our law? Repeat after me: the lower the bit rate set, the higher the compression will be. Now, you may be wondering why not just create all MP3s with low bit/high compression settings? Surely that would save a lot of file space? Well, there is a drawback to using a very low bit rate; it adversely affects sound quality. The lower you go the more detrimental the effect. If you wanted to compress an audio file which you wanted to sound as good as a commercial CD you would probably use a bit rate setting no lower than 128Kbits per second. Where the recording is simply spoken audio you can get away with a lower rate than you might, on say, a music track.

How we did it.

All of the recordings on our site are made available as MP3 files. The original recordings were transferred (imported) from cassette tape into a computer to make a digital sound file. This allowed the recording to be "cleaned", removing tape hiss and other blemishes. Finally, the sound file was compressed into an MP3 format.

There are several software packages that might be used to complete the transformation from tape to MP3 file and we don't claim that those which we used are the best, but we certainly are pleased with the results. The programs we used were Audio Cleaning Lab Deluxe 3 (ACL3) and NeroBurn 5 (Nero). You can find hyperlinks to both of them on our links page .

ACL3 was used to import the audio tapes to the computer and the resulting files were then cleaned by ACL3 before it exported them out as wav files (an uncompressed audio file format). Nero then stepped in to write the wav files out onto an audio CD. The uncompressed audio file on the CD was subsequently compressed by Nero to create our MP3s. (ACL3 is able to export a wav file out directly as an MP3, but the bit rates it offers do not go as low as Nero allows).

We used two levels of compression to create two sets of MP3s for our site; one highly compressed set for downloading from the site and a more lower compressed set for our CDs. We needed high compression to make certain the files we made for the site were as small as possible to keep transfer times (and your phone bills!) as small as possible. Because space on a CD was less of an issue it meant we could set the bit rate higher, ensuring a better sound quality in the MP3s on the CDs. We did it that way in case anyone wants to create their own uncompressed audio CDs (a task akin to pulling the quilt out of the pillowcase), which could then be played on any normal CD player. The low compression rates will ensure that they will sound as good, in many cases better, than the original tape recordings. Our hope is that the ministry contained on our site will be spread far and wide by people creating and distributing their own CDs. If you plan to do this please make certain that you look at our copyright notice.

And that, in a nutshell, is how we did it. If none of the above has put you off and you would like a less "compressed" set of instructions on how to create your own MP3s from cassettes, reel to reel tapes or even old vinyl, using the software we mention, then please go to our PDF page where you can download a pdf file covering the subject in more depth.