DSP - Digital Signal Processor
A Digital SIgnal Processor is a mathematical manipulation of the recording to improve or modify it in some way. The processor looks for discrete ways of altering time, audio and frequency to produce a better overall sound. The more DSP a device uses, the larger the file size but also can drastically alter the outputted sound. Both of these factors needed to be taken into consideration when looking at storage space or the achievement of a particular effect.
RAM - Random Access Memory
Random Access Memory is the storage space available on a computer to save the file. Limited space on the hard disk means only smaller files will be able to fit in there. This in turn means that due consideration will have to be given to the recording method to produce an adequately sized file.
File format (eg MP3, WAV, AIFF)
The file format will matter greatly as all files fall into one of two categories - lossy or lossless. Lossy formats mean that audio quality will sacrificed to produce smaller, compressed files. Lossless formats mean that there is no compression, producing larger file sizes but crisper, cleaner more realistic audio.
Audio output (eg Mono, Stereo, Surround)
The audio output will be a limitation that needs to be considered. if the recording is intended to have large bit depth and resolution featuring quality, realistic audio a mono output will not do it justice. A mono output will sound flat and monotone with any kind of presence or effect disappearing completely. Conversely stereo and surround produce more impressive audio but upscale the file size.
PCM - Pulse Code Modulation
Pulse code modulation is a technique that takes an analogue signal and converts it to a digital output signal. This is achieved by PCM taking a sample of the analogue sound every second. The number of samples per second, ranging from 8,000 to 192,000, is usually several times the maximum frequency of the analog waveform in Hertz (Hz), or cycles per second, which ranges from 8 to 192 KHz.
The result is useful in applications such as Skype, Face time or the use of mobile phones. This method would not be suitable for recording audio for films, games or TV however as the sound can be quite broken and choppy (due to the samples being taken once a second rather than every millisecond).
One of the key disadvantages of using PCM is that the equipment required is very complex with the results being far from the quality produced by digital devices.
Audio Recording Systems
In what types of scenario may you use the following audio recording equipment?
Midi – Multi Instrument Interface