Computer Based Audio Recording 101
I am going to start a series of posts on audio recording, mainly for my own benefit, but also for people out there who might benefit as well.
This first post will cover the basics of computer based audio recording. Whether you are recording a podcast or a full band, the principals are the same; sound waves are captured/generated by a microphone/instrument and then travel to a audio to digital converter, this converter converts the audio waves to a string of ones and zeros and then your recording sequencer of choice records and stores this data on your computer. This is about as basic as one can describe this process, and in reality it isn’t much more complicated than that.
The most important link in your signal chain has to be the DAC/ADC (digital to audio and audio to digital converter). You get what you pay for in this department, your $50 soundblaster soundcard (which is a DAC/ADC) is not going to sound as good as say a $2,700 Apogee Rosetta 800 but you have to live within your means and get the best you can afford. The sole job of the DAC/ADC or audio interface as I am going to call it from now on is to convert sound waves into digital audio data. Depending on your system specs, this can be 16bit or 24bit data. This number is basically the amount of digits in this series of ones and zeros used to describe the frequency and amplitude of an audio wave. Obviously the more bits, the more accurate a wave can be described.
Also depending on your audio interface is the Sample rate. Most of today’s converters offer sample rates like 44,1000, 96,000, 192,000, etc. The sample rate is basically the amount of snapshots the converter takes of an audio wave in one second and then uses the snapshots along with the bit length to produce the digital audio data that is then sent to your DAW (Digital Audio Workstation). So again, recording at 24/192k theoretically will produce a more accurate representation of a sound wave than recording at 16/44.1k, however a 24/192k file will be much larger than a 16/44.1k file. Your average everyday computer soundcard will record and playback at 16/44.1k. The Red Book standard for Audio Compact Discs is 16/44.1k as well.
Well I proceeded to get more in depth than I wanted to, but at least now you know what your poor computer has to do when you press record and jam out on your guitar. That is pretty generic version of how the whole digital audio process works, next time we will look at audio sequencers, plug-in effects vs. hardware effects, and how to hook it all up!