The recording itself is just the first part of home recording and podcasting. The process of editing, mixing and applying effects – also called post production – starts afterwards and is a big part of the project. Below you will find a brief outline of possibilities that recording software and effects processing offer.
Software
There are two ways of post production with the computer: software that is only able to edit one track and multi track software. With a mere podcast spoken by one person a single track software is sufficient. As soon as you want to add music in the background, multi track software is needed. The same counts for video productions that include voice-overs or background music.
The most common multi track software for PCs is Steinberg Cubase and for Mac it is Emagic Logic. Both are additionally available as affordable, entry level versions. If you don´t want to spend money you can also download free- and shareware, such as Audacity, from the internet.
Multi track recording software is mainly about blending the signals into one stereo mix. Simple mixing and adjustment of levels will in most cases not lead to good sound quality. To get the best result the tracks must be manipulated and changed in certain aspects through effects processing.
Effects Processing
The main impact on the sound is Equalization (also called EQ). With an EQ you can emphasize or de-emphasize certain frequency bands, which can either make different tracks stand out from each other or help different sounding tracks sound more similar. E.g. on a bass drum the frequencies above 6 kHz can be cut off and a boost at 80 Hz will create a more powerful sound.
As a general rule, you should try to shape the sound by reducing certain frequencies, rather than boosting others. In particular, excessive boosting of low frequencies is a common cause of less intelligible recordings. These “muddysounding“ recordings often result from the dreaded “smiley-face“ EQ curve, when lows and highs are boosted to the point where the all-important mid-range (critical to intelligibility) is effectively masked.
A compressor automatically turns down the signal´s peaks (loud parts) by a preset amount so they don’t cause distortion. Compression also reduces the difference between the loudest and softest note, so the apparent loudness is greater. Example usage: A singer might vary in loudness from very soft to very loud, but the compressor reduces the magnitude of these extreme changes.
As it appears very unnatural to hear sound without reverberation, the reverb effect is an extremely important effect. Reverb adds depth to the sound signal and makes it smoother but also more indefinite. It is used in all cases for vocal tracks, but be careful with too much reverb as the signal might diffuse and the vocals lose presence in the whole mix.
Other instruments such as guitars, strings and the piano also sound richer and more natural with some reverb. Impulsive instruments, such as drums, shouldn´t be manipulated with reverb as the attack easily becomes indistinguishable.
There are countless software programs and plug-ins available that add reverb to the signal. The versions that mimic certain environments provide the best outcome but they are also memory and processor intensive and require high powered computers.
Format
After the last step in the project - the mixdown of all tracks to a stereo signal - you need to decide where and in which format to save the files. When saving your files onto CD, use WAV files with 16 bit and 44.1 kHz as this is the standard CD format. This ensures that you will have a high quality file available if you want to re-use or re-edit the file later for a different project. You should make sure to record all tracks with 44.1 kHz as if you for example record with 48 kHz, the transfer to 44.1 kHz can cause artifacts.
A higher bit rate on the other hand is not critical. Especially if the post-production includes many steps, a 24 bit recording makes sense. Are the files intended to be uploaded on websites or used with an MP3 player, you should consider a compressed format that results in a much smaller file size. The MP3 format with 128 kb has become the standard and is viewed as equal to the original WAV signal. Critical ears though hear a difference and a compression with 196 kb per second results in a better sound quality. MP3 is not the only format but the most popular. Further formats are e.g. WMA (Windows), AAC (Apple) or Ogg Vorbis.
All formats have one thing in common: the encoding software discards some of the data that is deemed to be unnecessary or redundant and the more data that is discarded, the smaller the file size but the lower the sound quality. To summarize: it is best to save the initial recordings as WAV files to have the best possible sound quality. While there are programs that convert MP3s to WAV files, they do not make the resulting sound quality any better, because the data that was discarded when the MP3 file was created cannot be “added back in“.
