ANALOGUE VS DIGITAL Flashcards
What is analogue audio?
Sound waves that have been directly translated into electrical current, grooves in a record, or magnetic patterns on tape.
What is digital audio?
Sound waves that are represented by a series of numbers (samples) in a digital format.
What degrades analog audio!
Noise
Recording signal flow of analogue audio
Mic, mixing desk, reel to reel
Playback signal flow for analogue audio
Reel to reel, mixing desk, monitors
Purpose of mixing console
Gain staging
Is DA resistant to noise interference?
Yes
What is the use of plugins?
Attempt to emulate older sound of analogue
DA signal flow for recording
Mixing desk, D/A converter, computer
DA playback signal flow:
D/A converter, mixing desk, monitors
Hybrid Signal Flow for recording
- recording: mic → mixing desk → reel to reel → mixing desk → A/D converter → computer
Hybrid Signal Flow playback:
computer → D/A converter → mixing desk → monitors
pros of analog recording
- Shape of magnetic energy is identical to
the original pattern of the change in air
pressure - Harmonic distortion is a highly desirable
side effect of recording to tape - Audio is stored as it is recorded
cons of analog recording
• Tape is expensive • Cheap recorders suffer from excessive hiss and distortion • Analog recorders require continuous maintenance • In-depth editing is difficult and time consuming • Duplicating tape deteriorates audio • Synchronization is difficult
pros of digital recording
• Low distortion and hiss • Non-linear performance (random access) • Non-destructive editing • Data can be transmitted & transferred easily • Integration of audio into multimedia is relatively simple • Extensive range of tools available • Recording systems are more affordable
cons of digital recording
• Considered cold or clinical
• Data can be corrupted
• Easily copied/stolen
• Everybody with a computer and an internet
connection has access to a lot of the same
tools that professionals use
difference between commercial and professional grade audio interfaces
- commercial are bus powered
- using a great source of power creates a cleaner sound
- professional grade are built to be more stable and noise free as possible
What is the highest frequency that can be recorded with a 48kHz sample rate?
24kHz
T/F: The grooves in a record cannot be directly compared to the sound waves that they represent
false
The unit of measurement for digital audio Sample Resolution is:
kHz
T/F: High sample rates (such as 96kHz or 192kHz) result in much higher quality than the standard CD sample rate.
false
Analog audio is praised for it’s harmonic distortion, or tonal ‘warmth’.
true
Analog audio stores the continuous variations in sound waves down to the finest detail.
true
definition of Quantization
Individual samples are converted to a binary word
Digital audio is a stream of amplitude snapshots, just like video is a stream of still images
true
What process does the following definition describe? The voltage of incoming analog signal is measured at regular intervals thousands of times a second.
sampling
If the sample rate is fast enough, a digital stream of audio samples can perfectly recreate the sound that was recorded.
true
What does ADC stand for?
Analog to Digital Converter
What is the standard sample rate for CDs?
44.1 kHz
How many tracks could the earliest version of Pro Tools record?
4
The unit of measurement for digital audio Sample Resolution is
kHz
What is the standard sample rate for DVDs? _____kHz
48kHz
A word clock connection helps to prevent pops and clicks between different pieces of digital audio equipment.
true
Word clock connections are made between a master device and one or more slave devices.
true
Aliasing occurs when incoming frequencies are higher than half of the sample rate.
true
Word clock can be used for analog and digital equipment.
false
The purpose of dither is to:
Reduce quantization errors at low levels.
Aliasing only occurs when recorded frequencies are higher than the sample rate.
false
The process of dispersing white noise across the audio spectrum in dithering is called:
noise shaping
Dither is used to reduce quantization errors at low levels.
true
What term describes the removal of bits from a binary word?
truncation
What kind of filter is an anti-aliasing filter?
LPF
What is the standard bit-depth used for CD audio?
16 bit
How many possible values can be stored in a 1-bit word?
2
What is the standard bit-depth used for CD audio?
16 bits
Dither is used to reduce quantization errors at low levels.
true
The purpose of ‘word clock’ is to _____ digital audio equipment.
synchronise
Dither should be applied whenever audio is converted from a high bit-depth to a lower bit-depth.
true
What process does the following definition describe? The value of each sample is converted to a binary number.
quantisation
What is the Nyquist Frequency of 48 kHz audio? _____kHz.
24
What is the purpose of an anti-aliasing filter?
To remove frequencies higher than the Nyquist Frequency
High sample rates (such as 96kHz or 192kHz) result in much higher quality than the standard CD sample rate.
False
When sample values are ‘rounded-off’ to the nearest value, the resulting noise is called:
Quantization error
What does S/PDIF stand for?
Sony / Philips Digital Interface
The highest frequency that can be recorded with a 32kHz sample rate is _____kHz.
16
