![]() ![]() ![]() ![]() ![]() ![]() ![]() |
|||||
In a lossless format such as WAVE, the audio is saved raw and as is - like a TIFF file in digital photography. This is the best way to archive your most important music, though the digital file size can be roughly 10 times what its MP3 equivalent might be. The songs on your original audio CDs are essentially raw stereo audio files, so it's a good idea to keep your original audio CDs as archives. In a 'lossy' format such as MP3, the original raw audio is encoded (digitally processed) to permanently remove some data which your ears typically won't hear, in order to lower the overall file size. An analogy here is a photograph scanned and saved as a JPG file. You can fit a lot more MP3s on a CD or in an MP3 player than you can WAVE files. Not all MP3s are alike, either. Some MP3 encoders are better than others. Note that there are other methods (called codecs) available for saving audio files, like AAC (lossy, used in iPods) and AIFF (lossless). Some new codecs are also coming out, but need some gains in popularity before you can trust your music to them. What is MP3 and AAC? A higher compression results in a smaller file size, but lowers the sound quality. The sound quality of MP3s and AACs varies depending on the encoding method; in most cases we use a process which produces a high quality but large audio file, but we can adjust the compression technique to match the bandwidth you want. An advancement in MP3 audio compression is MP3Pro. It's fully compatible with "regular" MP3. It produces a smaller file size at lower bit rates without compromising sound quality. It's especially useful in website applications, and it's available at BluEarthArts. Why do some song clips I
listen to on music websites sound so bad? Our conversions to MP3 are high quality (even the web clips we do) and sound great! What resolution should I
choose for my MP3s or iPod songs? On our Blues Jam web pages, all MP3s from these live performances have been encoded at only 64 Kbps yet still sound clean and crisp (click here for an example of an MP3 encoded at 64 Kbs). For more discriminating listening we can up the encoding rate to 256 or even 320 Kbps; at those rates your MP3s or iPod files will be huge but a CD (for example) will still hold 5 to 6 hours of the highest quality MP3s available. Most people can't really hear a difference at these higher rates, but for those who can - this option is available at BluEarthArts. What is hiss/hum & noise
reduction? Noise reduction processes the audio in a track, then determines which frequencies tend to comprise the noise background over a given length of time; a special filter is then compiled and applied to weed those background noises out. For optimal results, BluEarthArts derives a special noise filter from each recording. Hum often occurs when using recording equipment too close to electrical wires, or from grounding problems around the equipment. Hum can also be substantially reduced in recordings by careful filtering. Another type of noise sometimes found in recordings - distortion - is more troublesome. Poor recording equipment and techniques can introduce harmonic distortion into the sound and, unfortunately, there's not much we can do with it. If your audio is clipped, though, (recorded at too high a level) we can usually restore the lost peaks.
What is
Normalization? What is EQ? Most people don't know that the playing head on their tape players gets magnetized over time. This magnetization actually begins to slowly but surely erase high frequencies from their tapes every time they're played. In repeated playings, the audio begins to sound muffled, but it happens so slowly that you probably won't even notice the degradation at first. The end result is a tape which sounds muffled and lifeless (click here for an after/before example from an old mono recording). EQ can help improve the sound of audio which has been damaged this way. Human speech can be made to sound brighter by boosting the sound frequencies which speech is made of. In many instances, the recording microphone may have been of a poor quality and may have actually boosted certain lower midrange frequencies which can make the speech sound "boomy". That can be reduced by using EQ to remove the offending lower frequencies. Why do my CDs skip or act
up? |
|||||