sound sources
...D-A) is used to reproduce the sound. The frequency at which the samples are taken is the ‘sample rate’. The sampler will accurately capture the sound as long as the sample rate is at least twice the highest frequency present in the sound. Samplers today use a sample rate of 44.1kHz (i.e., 44,100 cycles per second). Each sample is converted to a number. The number of digital memory determines the fidelity. ‘Lo-fi’ uses 12 or less bits (binary digits) and ‘hi-fi’ is 16 bits or more. Today most hardware samplers use at least 16 bits. Replaying the samples at a different sampling rate will change the duration and the pitch. So half-rate playback changes the pitch down an octave and doubles the duration. Looping Looping is repeating a portion of a sample over and over in order to create a continuous sound. When you loop a segment of sound you are playing through to the end of the loop and then instantly starting back at the beginning of the loop. A sound is usually looped during a point in its evolution where the harmonics and amplitude are static in order to avoid pops and glitches in the sound. Digital manipulation Once a sample is recorded the sound can be manipulated and processed. You can speed it up or slow it down, changing both tempo and pitch. You can filter it. You can play only certain portions of the sound, and repeat those in new rhythmic ways. You can also play the sound backwards. Pitch shift Pitch shift is used for changing the pitch of an audio signal without changing its duration. Truncation When manipulating a sample, truncation shortens a sample's length by trimming off parts of the beginning and/or end. Filtering Filtering is used to remove unwanted frequencies from an audio signal. Low Pass filters are the most common type of filter found in synthesizers. They only allow frequencies below the cut-off frequency to pass (Low Pass). High Pass filters only allow the high frequencies to pass and Band Pass filters only allow frequencies ...