Edit Your Streaming Audio File
By Douglas Taylor
Once you have your audio created you will need to edit the file in order to get a polished finished product. This is simple to do with the secret being to follow a series of steps for each and every audio file you edit.
Fix Your Mistakes
You can cut and paste your audio files just like a word document. In your main window you can click and drag the mouse over different parts of the file to select the part you desire to edit. When you have your selection made you can cut or copy it just like you would in your word processor. To cut out a mistake you made while recording just highlight the bad part and cut it out and the two pieces of audio you have left will come together just like magic. As you become used to working with audio clips, you will be able to look at a file and see what is wrong with it. Sometimes this will be better than listening to the file.
DC Offset
If the average between the plus and minus peaks in your file is not zero, the consequence is indistinct low-frequency distortion. This is called DC offset. It can be a problem even if you can not see it in your wave file for the reason that It affects where the zero crossings appear, which will have an effect on how smooth your splices are.
Although you won't be capable of hearing it in the .wav file, it will corrupt your file, as well as bring in more distortion if you use more processing to the uncorrected wave.
The DC offset utility fixes this, and should always be the first thing you do when optimizing your audio file. Once you have your file in one piece with all the mistakes cut out get rid of the Dc offset first
Compression
Your recording will most likely have some uneven places in it with parts being too quite and some places too loud. Compression can help smooth things out by giving you a more consistent volume level. Compression is sort of like a giant volume control that works a lot faster than you can do it by hand. Compression will give your audio more punch and it will most always sound better.
Basically a compressor reduces a sounds dynamic range. When the audio goes beyond a set level (threshold) the compressor will reduce the volume of the audio by a preset amount (ratio). It will do so at a predetermined speed (attack). When the audio signal goes below the level again it returns the audio to the original level at a predetermined speed (release)
Most software compressors have very good presets built in. These presets are a great place to start. They are labeled very clearly so start with the vocal preset for instance and adjust the controls slowly or maybe not at all until you are getting a great sound you are happy with.
Normalizing
When you have finished compressing your audio file you need to raise the volume level of the entire audio file. This is called normalizing and it is used to obtain the highest volume possible without going over 0 db. Going over 0 bd causes clipping which produces nasty distortion.
Fade In And Out
The last item you need to take care of is the final editing of your now optimized audio file. You need to make sure you have no empty space before or after the end of the recording. Highlight any space with your mouse and cut it out so the audio starts playing right away
The last things you need to do is highlight the first 4 seconds and go to process and add a fade in then highlight the last 4 seconds and fade it out. This will give you a nice clean professional sound.
When you are happy with the results of your optimization you now need to save your file as a wav file. You are saving as a wav file instead of mp3 because you want to preserve the file as the highest quality possible. It is now time to convert your file to the mp3 format and get it into a format that will stream over the Internet.
Doug Taylor has been creating audio online since 1999.