Beats Per Minute (BPM)
Bit
Bit Depth
Buffer
Bus
Byte
Clipboard
Clipping
Codec
Compression Ratio
(audio)
Compression Ratio
(file size)
Computer ID
Crossfade
DC Offset
The tempo of a piece of music can be written as a number of beats in one minute. If the
tempo is 60 BPM, a single beat occurs once every second.
The most elementary unit in digital systems. Its value can only be 1 or 0, corresponding to
a voltage in an electronic circuit. Bits are used to represent values in the binary
numbering system. As an example, the 8-bit binary number 10011010 represents the
unsigned value of 154 in the decimal system. In digital sampling, a binary number is used
to store individual sound levels, called samples.
The number of bits used to represent a single sample. For example, 8- or 16-bit are
common sample sizes. While 8-bit samples take up less memory (and hard disk space),
they are inherently noisier than 16-bit samples.
Memory used as an intermediate repository in which data is temporarily held while
waiting to be transferred between two locations. A buffer ensures an uninterrupted flow
of data between computers. Media players may need to rebuffer when there is network
congestion.
A virtual pathway where signals from tracks and effects are mixed. A bus's output can be a
physical audio device in the computer from which the signal is heard.
Refers to a set of 8 bits. An 8-bit sample requires one byte of memory to store, while a 16-
bit sample takes two bytes of memory to store.
The clipboard is the location where data cut or copied from ACID is stored. You can then
paste the data back into the software at a different location.
Occurs when the amplitude of a sound is above the maximum allowed recording level. In
digital systems, clipping is seen as a clamping of the data to a maximum value, such as
32,767 in 16-bit data. Clipping causes sound to distort.
Coder/decoder: refers to any technology for compressing and decompressing data. The
term codec can refer to software, hardware, or a combination of both technologies.
A compression ratio controls the ratio of input to output levels above a specific threshold.
This ratio determines how much a signal has to rise above the threshold for every 1 dB of
increase in the output. For example, with a ratio of 3:1, the input level must increase by
three decibels to produce a one-decibel output-level increase:
Threshold = -10 dB
Compression Ratio = 3:1
Input = -7 dB
Output = -9 dB
Because the input is 3 dB louder than the threshold and the compression ratio is 3:1, the
resulting signal is 1 dB louder than the threshold.
The ratio of the size of the original noncompressed file to the compressed contents. For
example, a 3:1 compression ratio means that the compressed file is one-third the size of
the original.
Each computer has a unique number, similar to a license plate. Sony creates an activation
number based on that number. Since the activation number is based on the Computer ID,
it is important that you have the ACID application installed on the computer where you
will be using it. The Computer ID is automatically detected and provided to you when you
complete the installation process.
The Computer ID is used for registration purposes only. It doesn't give Sony access to any
personal information and can't be used for any purpose other than for generating a
unique activation number for you to use the software.
Mixing two pieces of audio by fading one out as the other fades in.
DC offset occurs when hardware, such as a sound card, adds DC current to a recorded
audio signal. This current results in a recorded wave that is not centered around the zero
baseline. Glitches and other unexpected results can occur when sound effects are applied
to files that contain DC offsets.
312 | APPENDIX E
