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DIGITAL AUDIO BASICS
Music Technology Central York High School
82
DIGITAL AUDIO BASICS
Music Technology Central York High School
83
DIGITAL AUDIO BASICS
Music Technology Central York High School
84
DIGITAL AUDIO BASICS
Music Technology Central York High School
85
DIGITAL AUDIO BASICS
Music Technology Central York High School
86
DIGITAL AUDIO BASICS
Music Technology Central York High School
87
DIGITAL AUDIO BASICS
Music Technology Central York High School
88
DIGITAL AUDIO BASICS
Music Technology Central York High School
89
DIGITAL AUDIO BASICS
Music Technology Central York High School
90
DIGITAL AUDIO BASICS
Music Technology Central York High School
91
DIGITAL AUDIO BASICS
Music Technology Central York High School
92
DIGITAL AUDIO BASICS
Music Technology Central York High School
93
DIGITAL AUDIO BASICS
Music Technology Central York High School
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Music Technology Central York High School
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STUDY GUIDE Digital Audio Basics
You are responsible for knowing and understanding the following concepts and information concerning digital audio.
1. Define “digital audio.”
2. What are some things that utilize digital audio that we encounter in everyday life?
3. What is the difference between analog sound and digital audio?
4. What is a “sample?”
5. Describe the process of sampling, or A-D conversion.
6. Define “bit depth.”
7. Define “sampling rate.”
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8. What is the industry standard bit depth and sampling rate for:
Bit Depth Sampling Rate
CD Audio:
DVD Video:
DVD Audio:
9. Describe the process of D-A conversion:
10.What is a “buffer?”
11.When does “clipping” occur?
12.What is a “noise floor?”
13.What is “decibel” and what is it used for?
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14.What is the “threshold of hearing?”15.What is the “threshold of pain?”
16.Define “signal-to-noise ratio” or S/N ratio.
17.How is S/N ratio calculated (expressed in dB)?
18.What is error correction and why is it important?
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NOTES:
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Date Due:__________________ Name:______________________________
WORKSHEET How Analog and Digital Recording and CDs Works
1. What were two problems with analog recording?a) b)
2. What were the two goals of digital recording?
a) b)
3. What is meant by “fidelity?”
4. What two things affect the fidelity of a digital recording?
a) b)
5. What is the sampling precision (bit-depth) of CD audio?
6. What is the sampling rate of CD audio?
7. Name the four layers of a compact disc. (See “Cross-Section of a CD”) a)
b) c) d)
8. How wide are the bumps on a CD?
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9. How does a CD player read a CD?10. What is the job of the tracking system?
11. Define the following:
a) Subcode data -
b) Error correcting codes - c) Interleaving -
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DP4 DRILL 14 Importing Digital Audio
Import audio, Soundbite window, Waveform editor, Snip, Stereo Audio Track, Input, Output, Track Window Ruler 1. Open a new DP4 project and save it as “Drill 14.x.”
2. Use the following procedure (steps 3, 4 & 5) to import and edit sound effects into DP4.
a. Create a “story” using only sound effects.
b. You may use multiple audio tracks to overlap sound effects, if you wish.
c. Use “Stereo” tracks because all of the sound effects are stereo audio files.
3. Import a sound effect from the “Sound Effects” folders a. Open the Soundbites window (Shift+B)
b. From the Mini Menu in the Soundbites menu, select Import Audio c. Navigate to your source of audio (folders – but this can also be a CD or
MP3 file, iTunes file, Apple Loop, etc.)
i. The Sound Effects are in: Applications|MOTU DP4.6 Folder|Sound Effects
ii. There are two folders in there, each with 100 sound effects – check the black binder for lists of files
iii. To audition the sound files, click the speaker button on (lower right) so it is yellow. Then highlight the sound you wish to hear and it should play.
d. Select the file(s) you wish to import and click “Open”
e. The selected files should show up in your Soundbites window in DP4 4. Edit the soundbite in the Waveform Editor
a. Open your second “Main Window”
b. Click on “Soundfile” tab
c. Highlight the “Soundbite” in the Soundbite Window that you wish to edit d. Expand the horizontal graph to an appropriate resolution using the +/- e. Delete “silence” from the beginning of the bite (and the end, if necessary)
i. Drag to highlight the portion of the waveform you wish to delete ii. When you release the mouse button, listen – it will play the
selected part of the waveform – make sure you are not deleting any audio
iii. Select “Snip” form the Edit menu 5. Place the soundbite on an audio track
a. Create a “Stereo Audio Track”
i. Project|Add Track|Stereo Audio Track (Shift+Command+S) ii. Set Input column to “Built-in Audio 1-2”
iii. Set Output column to “Built-in Audio 1-2”
b. Drag the soundbite from the Soundbite window to your track
i. Place your cursor over the double “~” and the cursor becomes a hand
ii. Click and drag to the stereo audio track
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iii. Place the bite where you want it to be
iv. Change the resolution of your time grid to place the soundbite more accurately
1. Use the -/+ in the lower right corner of the track window to change the grid resolution
2. Soundbites will “lock” into the grid NOTES:
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DP4 DRILL 15 Recording Audio in DP4
Mono Audio Track, MOTU Audio System, Audio Monitor, Name soundbites, Delete soundbites
1. Open a new DP4 project and save it as “Drill 15.x.”
2. Record one group member counting from 1 - 10. Leave a short pause between each number
a. Create a new Mono Audio Track:
i. Project|Add Track|Mono Audio Track (Shift+Command+A) ii. Set Input to:
1. Room 739 – set to “Mic/Guitar1”
2. Room 738 – set to “Analog1”
iii. Set Output to “Built-In Audio 1-2”
iv. Record enable the track b. Check your recording level
i. Open the Audio Monitor (Shift+A)
ii. Set your gain (on the MOTU 828) to avoid clipping
1. Remember – the goal is to get the hottest signal possible WITHOUT clipping
c. Record your sound d. Name your Soundbite
i. In soundbite window – option-click on the Soundbite Name and name it “Numbers”
ii. Scroll over to the File Name column and option-click to give the file the same name
iii. You must name BOTH the soundbite and the file e. Delete any unused soundbites
i. Highlight the unwanted soundbites in the soundbite window ii. In the Mini Menu, select “Delete”
iii. The computer will ask you if you want to delete and flush the Undo History, answer yes to all.
f. Save and close your Project
3. Transfer your project to your station computer a. Make sure your Station computer in on
b. On the Recording Booth computer, double-click on the hard drive to open a finder window
c. Click on “Network” in the top left column of the finder window d. Set the view to “column view”
e. Select the “My Network” folder (“Local” on some computers)
f. Find your station computer – the name will be “MIDI LAB x” with “x”
being the number of your station (01-10).
g. Select your computer and click on connect h. Type your user name in for username
i. Period 1 use “block1”
ii. Period 2 use “block2”
iii. Period 3 use “block3”
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iv. Period 4 use “block 4”i. Leave Password blank j. Click “Connect”
k. Select the User folder for your period l. Click OK
m. Your User folder will show up in the finder window as a “server”
n. Click on your server and navigate to your “Documents” folder o. Drag the project folder from the recording booth computer to your
Documents folder and drop it in to copy it.
p. Be sure to copy the entire folder and all of its contents
q. When copying is complete, drag the “server” icon from the desktop to the trash
NOTES:
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DP4 DRILL 16 Manipulating Digital Audio
New soundfile from selection, Placing soundbites in sequence 1. Open “Drill 15.x.” Use “Save as…” to save it as “Drill 16.x.”
2. Open the “Numbers” soundbites in the Waveform editor (see Drill 14) 3. Make a new soundbite for each number 1 through 10.
a. Highlight the section of the waveform which represents “one”
b. From the Mini-Menu in the Waveform editor, select “New Soundfile from Selection”
c. A new file will appear in the Soundbites Window; change the “Name” and
“File Name” to “01”
d. Use “Snip” to trim any silence before and after the word.
e. Repeat this process for each number (02, 03, 04,…10) 4. Place your edited soundbites into your Track window
a. Delete any information in the Track window
b. Drag and drop the mono soundbites into the mono audio track i. The files will automatically snap to the grid
ii. Use the -/+ in the lower right corner of the Track window to change the resolution
iii. Place a number on every beat using the following patterns:
1. Ascending – Start in 1|1|000 2. Descending – Start in 4|1|000 3. Even – Start in 7|1|000
4. Odd – Start in 9|1|000
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NOTES:Music Technology Central York High School
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DP4 DRILL 17 Introduction to Audio Effect eVerb, Reverb, Chorus, Delay, Echo, Pre-Amp
1. Create a new project saved as “Drill 17.x” in your Documents folder.2. Go to the Music Tech web page. Navigate to the “Assignments” page and download the zip file “Drill 17 Audio.”
a. Use Safari
b. Control-click or Right click on the link and select “Download Linked File”
c. After file finishes downloading, go to the desktop and double-click on the zip file to unzip it – this will create a folder that will contain the audio files for this drill.
3. Import the audio files from the downloaded folder into your DP4 project.
a. In the Soundbites window, select “Import Audio” from the mini menu, or click on the I in the Soundbite window menu bar
b. Navigate to the downloaded folder and select all of the audio files c. Click “Open” to import.
4. Apply “Echo” to the soundbite “Trumpet.”
a. Open the soundbite “Bass” in the waveform editor i. Highlight the soundbite in the soundbite window ii. Click “Open Waveform Editor” button on control panel b. Select the entire waveform
c. Open “Echo’ audio effect – Audio|Audio Plug-Ins|Echo d. Experiment with the settings to get a sound you like
i. Click “Preview” to hear your changes before you apply e. Click apply to save and re-write the sound file
Use the procedure from #4 to apply more effects:
5. Apply “Pre-Amp” to the soundbite “Guitar”
a. Experiment first with “Coloration” and then try EQ and Compression 6. Apply “Chorus” to the soundbite “Bass”
7. Apply “Delay” to the soundbite “Tenor Sax”
8. Apply “Reverb” or “eVerb” to the soundbite Alto Sax
9. Using either the Trumpet or Alto Sax soundbite, apply several of the effects to see what you can create, e.g. add chorus and reverb to Trumpet; or add delay and reverb to Alto Sax
