Chapter 1 Flashcards
What is a waveform?
The shape of a sound. It gives a sound it’s unique character and tone.
what is frequency?
The pitch of a sound. Measured in cycles per second (CPS) or hertz (HZ)
what is amplitude?
the intensity of a sound. Measured in decibels (dB)
how does recording and playing back analog audio work?
microphone converts acoustic energy into electrical current. captured signal can then be played back by translating electrical current back into variations in air pressure.
what is sample rate?
the frequency of digital measurements of audio
what is nyquist theorem?
sample each cycle at least twice to capture the audio frequency
what is the minimum sample rate that can be used?
sample rates must be at least 40 khz for full spectrum audio
what is bit depth?
the number of binary digits used to represent each sample; determines the accuracy of measurements. larger bit depths provide more dynamic range.
how much does dynamic range increase per bit?
6 dB per bit. to estimate dynamic range, multiply bit depth by 6.
what is the minimum bit depth?
11 bits. Pro tools uses 16 bits to accommodate noise floor & headroom.
do higher bit depths and sample rates generate larger or smaller files?
larger
what is one minute of mono audio at 44.1 khz /16 bits equivalent to?
5 MB of disk space.
does increasing sample rate or bit depth increase or decrease required disk space?
increases
in regards to digital transfers, does keeping audio in the digital domain prevent signal degradation?
yes
what are some common digital connections available on Pro Tools audio interfaces? what type of connector jack does each use?
S/PDIF (RCA jack)
AES/EBU (XLR jack)
3 software options available with Pro Tools
Pro Tools First, Pro Tools standard & Pro Tools Ultimate
Define host based systems
rely solely on the processing power of the computer
define DSP accelerated systems
computer processing is supplemented by digital signal processing (DSP) chips for mixing and real time processing
name the audio interfaces compatible with standard pro tools
mac - any interface with a supported core audio driver
windows - any interface with a supported ASIO driver
(often powered by the usb bus, up to 32 channels of simultaneous I/O)
name 3 interfaces made by Pro Tools/Avid
Pro tools HD OMNI - 2 min/DI inputs, built - in preamps, 4 line inputs and 8 line outputs
Pro Tools HD I/O - available a 8x8x8 ( 8 analog in, 8 analog out and 8 digital in/out) 16x16 analog and 16x16 digital
Pro Tools HD MADI - 64 channel digital interface
What are the file naming conventions?
current - ptx
older - ptf, pts & pt5
what are the 2 audio files extensions in pro tools?
wav and aif
