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38 Cards in this Set
- Front
- Back
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Can degrations be detected in analog systems? |
No |
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Is the sampling frequency of a digital system dependent or independent of the signal frequency? |
Independent |
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What form of digital representation for audio is in virtually universal use? Provide both name and Acronym. |
Pulse Code Modulation (PCM) |
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How do we find the address range of a particular binary word length? |
By raising 2 to the power of word length. |
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What is the process referred to as 'slicing'? |
When the binary signal is degraded by noise, and is rejected by the reciever |
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Approximately how many bits per second are required for a single high quality audio channel? |
1 millions |
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Name two factors which can affect the sound quality of a DAC which does not have timebase correction implemented? |
-Type of data cable -Power supply noise |
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On a hard disk recorder what might take place when time compression is implemented? |
Might move to another track |
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What is another application of time compression? |
To allow several channels to transmit simultaneously |
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What is a crystal oscillator used for in a digital audio recording system? |
Word clock |
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What is a 'burst error'? |
When dropouts cause a large number of bits in one place to be in error. |
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What are two causes of burst error? |
Scratches or containments |
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What is the difference between error correction and error concealment? |
Error Correction: is an absolute fix and is undetectable Error concealment: Hides errors but can still affect audio |
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What is a PPM meter designed to do? |
Responds to peaks as fast as our ears respond to distortion. |
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What are the lowest and highest hexadecimal values in a 16 bit audio system? |
0000 - Lowest FFFF - Highest |
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What does timebase correction consist of in relation to store media and/or transmission channels? |
Aligning jittery signals |
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Shortening the word length is a form of ???? and will require ???? |
-Quantizing -Dithering |
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What does a phase-locked loops excel at? |
Genlocking |
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What is a VCO? |
Voltage Controlled Oscillator |
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What is multiplexing used for? |
Sending several signals down one channel |
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Can filtering modify the frequency and phase response of a system? |
Yes |
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What is necessary to move a signal from the time domain to the frequency domain? |
Discrete Fourier Transform (DFT) |
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What are the two main classes of digital filters? Write acronyms and what it stands for. Which one is perfectly phase linear? |
FIR - Finite Impulse Response (Perfectly Phase Linear) IIR - Infinite Impulse Response |
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What is meant by "wider window effect"? |
When a digital channel has a higher bandwidth and greater headroom than needed |
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How is the bit rate of a digital signal determined? |
(Bit depth) x 2 x (sample rate) = BPS |
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Are sampling and Quantizing dependent or independent of each other? |
Independent |
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What is the major design consideration for filters in digital audio systems? Why? |
-Anti-Aliasing Filter -To prevent artifacts |
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What is 'droop' in the sample and hold stage? |
An unwanted slow change in the held voltage |
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What is meant by 'dielectric relaxation' in the sample and hold stage and whats it's result? |
Can cause the value of one sample to be affected by the previous one |
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What is 'sampling clock jitter'? |
Samples taken at the wrong time |
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Does tolerance to jitter increase or decrease as wordlength increases? |
decrease |
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What is a tolerable amount of jitter? |
121 Pico Seconds |
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What does a step ladder quantize? |
Height |
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What is the maximum quantization error in a digital system? |
1/2 Quantization Interval |
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Does dither correlate or decorrelate the quantization error with the signal? |
Decorrelate |
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What is the result of low amplitude signal when not dithered? |
Granulation noise |
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What has to be done when reducing the wordlength of a digital audio signal? |
Add dither |
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In reference to dither what is a PDF? |
Probability Distribution Function |
