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Arthur Garros
Really great learning experience today with Josh as we dove deeper into the understanding of sound. He answered all my questions and we constantly found more things to branch off on based on what I was asking. This was a really well rounded conversation and I can feel that I am starting to grasp these concepts well.
Notes/Questions:
Sound waves function similarly to how film frames do, in a sense that many samples of the wave amplitude are taken and then played back at the same rate to create the illusion of a continuous wave. - Super interesting how many factors of sound can be related to film and photography, it also makes it easier to understand. - Question: Why take small samples of the wave and not record the whole wave? Is this not possible? Why create the illusion of a continuous wave? Are we not able to capture and replay the actual thing?
- The way it is sampled doesn't create a perfect sound - interpolation (estimates the value of a function at a point from its values at nearby points) completes the wave
Transduce - Convert one form of energy into another.
A microphone transduces the variations in air pressure into an analogous change in electrical voltage.
Analog to digital converter takes discrete voltages and assigns numerical values to it - process known as quantization. What are these numbers? are these numbers the voltage?
When playback is initiated, the numbers are fed into a DAC and then to an amplifier - this is how the sound is played back correct? would you mind going over this?
Bit Depth - the number of bits used to define the aplitude of each sample - It compares this to pixels, does this mean the quality of the sound is better the higher the bit depth?
Sample rate is over time
Bit depth is amplitude, how much it is - just like pixels - the more
Bit can have two values - 1 or zero - This is what we were talking about with digital information coding - is this the same thing? Bits are information - data.
DSD (direct stream digital) uses a system to average the difference between two samples to anticipate the value of the next sample - With this kind of technology in anticipating the next sample, can we start to see the possibility of a computer making its own music? - Artificial intelligence
Why doesnt pro tools support the use of DSD?
Aliasing can add frequencies to the digital sound that werent present in the original sound - so can aliasing actually relate to the computer making its own music again? Can this be stylistic? or does it sound horrible
I didn't understand the relation of aliasing to the camera work ( page 8 )
You must go much higher than the nyquist frequency in order to preserve frequency and amplitude accurately
Nyquist theorem - frequency at which Samples taken must be two times the highest frequency being recorded
compressing files reduces the sample rate of the music
standard bit depth for a CD is 16 Bits - This means that every 44,100th of a second a 16 bit sample is taken - every minute of audio on a CD uses roughly 10 MB - A compact disc (700 MB) Can hold 70 minutes of stereo audio.
It is not uncommon for a pro tools session to have between 24 and 40 tracks - Does this refer to vocal, drum, guitar, etc?
Recording 24 tracks simultaneously at 32 bit/192k will use about a gigabyte per minute.
Can you make a whole song on a sampler or sequencer? What are the limitations of both? - Would the sound be quite electronic?
Any sound in digital form is a series of numbers or information. - does this refer to the ones and zeros? How can this relate to the picture?
DBFS - DB relative to full scale
Pulse Code Modulation - Taking an analog signal and putting it into its digital form. Pulse CODE - coding for sound
DB - zero DB is nothing added and nothing taken from the original sound
Decibels unit of measurement for sound pressure level.
Compressing a file - chopping off the loose ends - taking the essential parts of the song and leaving out the stuff you dont hear anyway.
KBPS - Killabits per second - Compression rate - Another sample of the sample. The higher the KBPS the bigger the file - (taking more pictures).
