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BLASTER Master
Tutorial
NOTE: The SAMPLE1.VOC example file is not included with the
shareware version. Substitute any VOC file.
The future of sound recording is digital. Digital recording,
also known as sampling, uses a system of numbers to
represent the sounds recorded. Because the sound is stored
as numbers, the quality of the recording never changes.
Unlike analog recordings like tape and vinyl records that
lose fidelity each time a copy is made or the record is
played, a digital recording will always sound the same. With
the release of the Sound Blaster, PC users can explore the
world of digital recording.
Another big advantage of digital recording is that sounds
can be easily edited and manipulated mathematically. Usually
when a digital recording is made, there are segments at the
beginning and ending of the file that need to be trimmed
away. If you are recording speech, there will be "ugh"
sounds and long pauses that you will want to remove. Your
digital file will be smaller and sound more professional by
using these simple editing functions. This is where BLASTER
Master comes in.
BLASTER Master is a shareware program for editing sound
files. It is graphically based and has a very elegant and
intuitive user interface. But do not let the simplicity of
the user interface fool you. BLASTER Master is one of the
most powerful tools for manipulating digital files
available. All the basic editing functions are included.
Segments of the sound file can be removed, saved, moved,
copied and more. In addition to these basic block functions,
BLASTER Master also includes a tool kit of advanced digital
signal processes (DSP) for altering your sound files in ways
that are nothing short of amazing! With a little practice
and experimentation, you will be able to combine the many
functions in BLASTER Master to create sounds you never
dreamed were possible.
This is a short tutorial on using BLASTER Master. We will
cover some basic editing and also have some fun too! Here is
a list of some of the features we will explore.
* Echoing files with different delays and
echo volumes to achieve a variety of effects.
* Reversing files to see what they sound
like backwards.
* Changing the pitch so your voice sounds
like either a Munchkin or a giant.
* Adjusting the volume of sound files
* Fading the volume at the beginning and end
for very professional sounding results.
* Mixing sound files together to make a
combined file just like a multitrack recorder.
* Looping segments of sound files for some
really cool Rap DJ effects.
These are only a few of the processes we will explore. Don't
worry if you don't understand some of the features. By the
time this tutorial is completed, you will be well on your
way to becoming a Sound Blaster Master!
GETTING BLASTER MASTER UP AND RUNNING
This tutorial assumes that you have already correctly installed
BLASTER Master.
Here are a few tips for getting the most from the software:
You will need at least an 80286 based IBM PC compatible. Sound
processing requires alot of computer system resources. The
faster your computer runs and the faster your hard drive reads
and writes the better. Since most of the DSP functions require
thousands, if not millions, of calculations, a math co-processor
is very handy, but not required. 80486 DX processors have a math
co-processor built in, so these CPUs naturally work quite well.
You will also need a high resolution EGA or standard VGA
graphics system to run the software. BLASTER Master visually
plots the wave form to make editing easier and quicker. If you
want to edit individual segments of the file for cut and paste
type operations, you will need a Microsoft compatible mouse. You
will also need alot of free 640k memory. Since BLASTER Master is
a large program capable of working with very large files, I
recommend a minium of 560k free memory. You might could get by
with slightly less, but some of the functions might not be able
to work correctly. Most PCs sold today come with at least two
megabytes of memory. We are only concerned with how much 640k
DOS memory is free. That's what counts for running programs.
Last but certainly not least, I recommend you have plenty of
free space on your hard drive. Even though the unregistered
shareware version of BLASTER Master will only process files no
larger than 25 seconds in length, you can quickly use up several
megabytes of disk space. A 25 second stereo file sampled at
22khz uses about 1.2 megabytes of disk space!
A WORD ABOUT SHAREWARE
BLASTER Master is a shareware program. In other words, it is
released in a form that may be shared with others. It is not
public domain. It is a copyrighted program and subject to the
same legal protection as all copyrighted works. BLASTER Master
can be found on BBS's and online services like GEnie, CompuServe
and America Online. Unlike most shareware, you are not limited
to only 30 days of use. You may use the unregistered version of
BLASTER Master for as long as you like. I hope you enjoy it! I
do this because many of my BLASTER Master users are students and
coming up with even a paltry sum of $29.95 is very hard. If you
are able to pay for the software, then I would appreciate your
support.
When you register BLASTER Master, I send you a code number to
remove the 25 second editing limitation. This number works on
all versions of BLASTER Master. Not only do you get unlimited
use for the version you currently have, you will also have
unlimited use with the frequent updates of the software. As long
as people continue to support BLASTER Master financially, I will
continue to produce updates.
A QUICK TOUR THROUGH BLASTER MASTER
We are ready now to learn how to navigate through the functions
and dialog boxes of the program. As stated earlier, I strongly
recommend the use of a mouse. In most cases, you will only need
your keyboard for entering a few function parameters and
entering file names. If you should be using your keyboard, you
can advance through the dialog boxes using the TAB key. The TAB
key combined with the SHIFT key moves in the reverse direction.
You will also find the arrow keys and the PgUp, PgDn, Home and
End to be very useful.
STARTING BLASTER MASTER
From the DOS prompt, type:
C:>BMASTER [ENTER]
The program will clear the screen and begin "looking" for your
Sound Blaster. If everything is as it should be, you will see a
light blue graphic screen with the BLASTER Master logo and a
large dark blue dialog box titled, "Select Sound File". This is
the opening screen and where we will select our sound files
from. The top of the File Select dialog box contains an input
box for entering file names from the keyboard. "*.VOC" should be
high-lighted within this input box. Just below the input box is
displayed
the current path. A large list box is displayed in the center
and to the left of the File Select dialog box. All of the files
with a VOC extension in the current path are displayed. This
list box is used to quickly and easily select sound files
without having to type them in. To the right of the list box is
another list box that displays the disk drives on your system.
This list box is very handy for selecting other drives and
subdirectories. Both disk drives and subdirectories are
displayed in this list box. Selecting the ".." selection will
cause the current path to fall back one directory level. In
other words, if the path displays:
C:\BLASTER\
Choosing the ".." will change the path display to the root
directory or:
C:\
At the bottom of the File Select Dialog box is a row of six
light blue buttons. The functions of the buttons are described
below:
PLAY
Play the selected sound file. You can choose this function from
the keyboard by using ALT-P.
RECORD
Record a new sound file. Choosing this function brings up the
Record dialog box. We'll learn more about it later. You can
choose this option from the keyboard by using ALT-R.
DELETE
Delect the selected sound file. Because sound files take up
quite a bit of disk space and experimentation is usually
required to get the effect you want, I have included an option
to "clean up" un-needed sound files. Please be very careful when
using this option! You can choose this option from the keyboard
by using ALT-D
IMPORT
Import other sound file formats. Choosing this function brings
up the Import dialog box. Windows 3.1 Wave files, raw SND files
and Amiga IFF files can be loaded into BLASTER Master from here.
We'll learn more about importing files later. You can choose
this function from the keyboard by using ALT-I.
ACCEPT
Accept the selected sound file for editing. Mouse users can also
"double click" the left mouse button to select a file for
editing without using this button. Keyboard users can choose
this option by using ALT-A.
QUIT
Quit BLASTER Master and return to DOS. You can choose this
option from the keyboard by using ALT-Q and [ENTER].
Sound Blaster Pro users will also see four controls for
adjusting the onboard mixer. The Master volume, VOC player
volume, Microphone and Line In volumes can all be quickly
adjusted by using these sliders. These controls are active
during playback.
PLAYING A SOUND FILE
Now let's select a file and play it back. The file list box
should display the file EXAMPLE1.VOC. Using your mouse, place
the white arrow over EXAMPLE1.VOC and press the left mouse
button only once. If you are using the keyboard, press the TAB
key once to highlight EXAMPLE1.VOC and press [ENTER]. The file
name input box should now display "EXAMPLE1.VOC" instead of
"*.VOC". Using the mouse once again, place the white arrow over
the PLAY button and click the left mouse button once. Keyboard
users can press the ALT key and the P key at the same time. A
red, shadowed box will appear with some useful information about
the sound file during playback. This is the Playback Information
box. It tells you the name of the file, how big it is, what the
sample rate is and the type of file. Playback can be stopped by
clicking the left mouse button or pressing the [ESC] key. Sound
Blaster Pro users can also adjust the various mixer volumes
during playback.
ENTERING THE WAVE EDITOR
Now that we've heard the file, let's take a look at it! Using
your mouse, place the white arrow over the ACCEPT button and
press the left button once. Keyboard users can press [ENTER] or
use ALT-A. The File Select dialog box and the logo will
disappear. A graphical representation of the sound file will be
drawn on the upper section of the screen. From this display, we
can see where segments of our sound files start and end. The
width of the screen represents the playback length of the file.
The height of the screen represents the amplitude or volume of
the playback. This visual interface makes it very easy to see
individual segments of sound files. The vertical grid lines
divide the sound file into seconds or in the case of very long
files, into minutes. With very little practice and
experimentation, you will quickly begin to develop a "feel" for
editing sound files.
Below the wave form display is some very useful information
about the file we are currently editing. The name of the file,
length sample rate and playback time is always displayed. To the
right of this information are eight buttons. These buttons are
used to select DSP functions that will act upon the entire file.
Placing your mouse cursor over a button and pressing the LEFT
mouse button will select the function. Keyboard users can use
the TAB and Shift-TAB keys to highlight the desired option and
then pressing the ENTER key to select that function. The two
farthest buttons to the right are very important. They are the
NEW and MORE buttons. Selecting NEW will allow you to select
another sound file. Don't press it yet though! The MORE button
will cause the function buttons to change. Select the MORE
button now. You should see seven more functions appear. The MORE
button is still there to go back to the original functions.
Current Time Display
Lets move the mouse cursor across the wave form graph. You will
notice that the time display across from the Playing Time
changes as we move the mouse cursor back and forth across the
wave for graph. This feature displays the approximate time of
the sound file at the point the mouse cursor is positioned over.
I am sorry but keyboard users do not have an equivalent for this
in the software.
Setting the Marker
With the mouse cursor still in the wave form graphic area, press
the RIGHT mouse button. Just below the mouse cursor position on
the blue bar a small white triangle will appear. This marker
will come in very handy in the future. It can be used to mark a
reference point as a reminder. The INSERT and MIXER functions
can also use the marker as the position to begin their
processes.
The Vanishing Menu
When we move the mouse cursor to the upper most area of the wave
form graphic area, a pull-down type menu will appear. It will
remain visible as long as the mouse cursor is over it or the
SHIFT key is held. Moving the cursor away will cause the menu to
vanish once again. Now you see it... now you don't!
The Vanishing Menu contains four sub-menu options:
FILE
These menu options allow you to select a NEW file, SAVE the
current file, SAVE AS a new name or sound file format, IMPORT a
new sound file, RECORD a new sound file and QUIT the program
and return to DOS. The ABOUT option will display some very
useful information like the BLASTER Master version number, your
soundcards DSP version and the DMA, IRQ and PORT settings.
OPTIONS
These menu options allow you to LOOP play the sound file over
and over again, SAVE SCREEN COLORS and if you have made a change
to the sound file, an UNDO or RETURN TO ORIGINAL option is
available.
TOOLS
These menu options correspond to the same DSP functions as the
lower buttons. There are some options not available from the
buttons: The PANNING function allows a stereo file to pan from
speaker to speaker. The SILENCE function allows silence bytes to
be inserted into the file to extend the playback time. The MAKE
MONO function converts a stereo file to a mono file. The HISS
function (Noise Gate) removes all bytes below a certain
amplitude.
HELP
This menu option displays a simple online help screen. The DSP
functions are described in more detail than just the button
labels. This is a handy reminder from time to time if there are
features that you have not used very often.
Marking a Block
Now that we have had a look at functions for working with a
whole sound file, we are ready to see some Block functions.
Processes that function with segments of the file, like cutting,
saving and moving segments require that way to identify the area
we want to work with. This selection process requires a mouse.
Keyboard will not be able to select a block for processing.
We mark a block by placing the mouse cursor over the wave form
graph at the point we want to start and pressing the LEFT mouse
button. A blue line will appear at the point the mouse cursor
was over and the function buttons will disappear. If you have
selected an area you do not want, press the ESC key and the blue
line will disappear and the function buttons will pop up again.
The blue lines can not be moved with the mouse. Assuming the
first point is what we want, position the mouse cursor over the
wave form graph where you would like the block to end and press
the LEFT mouse button once again. Our block should be surrounded
by a blue box and eight new buttons will appear where the
function buttons were before. Since we can not move the blue box
lines, it is always a very good idea to select slightly more
area than we need. You can ZOOM into the block and continue to
mark new segments until you have exactly the block you need.
Don't worry if you don't like the new block, UNZOOM will return
you to the previous segment. You can ZOOM up to 128 times or
until the sample to pixel resolution is 1:1. The current
resolution is displayed over the function buttons to the right
of the screen. The size of the current block is displayed to the
left of the File Size display. The playing time of the block is
similarly displayed across from the Playing Time. With very
little practice, you will quickly learn to mark a block with
surgical precision.
Block Functions
As mentioned earlier, the DSP function buttons have been
replaced with processes that act upon the selected block rather
than the whole sound file. Even the Vanishing Menu has different
options and a different help screen now. The PLAY button now
will only play the block and the NEW function discards the blue
box and returns to the original file.
The CUT Function
The most common editing feature used in block mode is the CUT.
There is usually some unwanted sample data at the beginning and
end of the sound file that needs to be removed. There may also
be some undesirable vocal components like "ughs" and breath
sounds that should be removed to have a more professional sound.
We will cover all the functons later in the tutorial.
Handy Tip
When trimming the front and end of a new sound file, always CUT
the left-most segment first. BLASTER Master uses a DOS function
to resize an UNTITLED or edited sound file when the right-most
segment is removed. This is much faster than having to make a
copy of the new file. You'll like it!
The ZOOM/UNZOOM Functions
The currently selected block can be displayed in more detail by
using the ZOOM function. Position the mouse cursor over the ZOOM
button and press the LEFT mouse button. The wave form graph will
change to display the block only. A new block can be selected
with the mouse cursor and LEFT mouse button as before. We can
continue to mark and ZOOM until we reach a sample to pixel
resolution of 1:1. Selecting the UNZOOM function will redisplay
the previously marked block in ZOOM mode until we return to the
original block. Try the UNZOOM function now.
Exiting the Wave Editor
Now that we have seen how to mark a block, select the NEW button
and press the LEFT mouse button (or press the ESC key). The blue
box will disappear and the DSP function buttons will reappear.
Select the NEW button again (or press the ESC key) and you will
be returned to the File Selection Dialog Box. If a change was
made to the sound file, a dialog box will appear to SAVE the
changes. We will talk more about that in the next section of
this tutorial.
Handy Tip
You can quickly quit BLASTER Master and return to DOS from the
Wave Editor by pressing CTRL-Q!
Using the DSP Functions
Now that we have taken a quick tour through BLASTER Master, you
should be familiar with the user interface and navigating
through the software. We will cover a few of the more common DSP
functions that operate on the entire sound file. Some of the
functions will require some parameters and other functions will
not. The functions requiring user supplied parameters will
require some experimentation and experience to achieve the
results you want.
The ECHO Function
An echo occurs when accoustic sound waves that have passed our
ears are reflected back from some surface that is off in the
distance. The distance of the reflecting surface and how well
the sound is reflected determines the kind of echo that is
produced. One of the more common DSP functions and also one of
the more versatile functions is the ECHO. Everything from short,
gated reverbs to continuous canyon echos can be processed using
this single function. A bit of echo can help to sweeten a voice
recording and produce a more professional sound. Three user
supplied parameters are required to process an echo:
Time Delay
The time delay determines the point in which the echo is
returned. The range of this parameter helps determine whether a
reverb type effect is achieved or a long canyon type echo. This
parameter ranges from 60 milliseconds to 400 milliseconds. The
majority of the echos desired will probably be in the 60 to 200
millisecond range. This parameter is the same element as the
distance of the reflective surface in an accoustic echo.
Mixture
The mixture is how loud the echos will be mixed into the
original sound. This is a very important parameter for how the
resulting echo will sound. Remember to not go overboard on this
setting. A setting of 30% to 60% is usually all that is needed
to achieve a very realistic result. This parameter is the same
element as how well the distant surface reflects the accoustic
sound waves. The louder the accoustic echo is returned, the more
reflective the distant surface is.
Finite or Infinite Filtering
This parameter determines how many times the echo will be
repeated. Finite means the echo will only be repeated once. This
is very good for gated reverbs or when the sound file is very
complex. The Infinite filter causes the echo to repeat over and
over until it eventually fades away. This is a more natural echo
but does not lend as well to reverb effects of short delay.
Echoing a Sound File
We will apply some echo to the SAMPLE1.VOC sound file now. From
the File Select dialog box, select the SAMPLE1.VOC file. As
discussed earlier in the tutorial, you may select this file by
using the mouse or the keyboard. If you have correctly selected
the sound file, you should now be in the Wave Editor and
SAMPLE1.VOC should be graphically displayed. Using the mouse,
place the cursor over the ECHO button and press the LEFT mouse
button. Keyboard users can press ALT-E to select the ECHO
function. A ECHO function dialog box will appear in the center
of the wave form graph. We will need to add the delay and volume
mixture parameters using the keyboard. The Delay field should be
highlighted. We will use a delay of 150 milliseconds. Enter the
following number:
150 [ENTER]
The Mixture field should now be highlighted. We will set the
volume mixture to 45. This will give an echo that is not too
overwhelming. Enter the following number:
45 [ENTER]
The OK button should be highlighted now. There is another
parameter that we could choose to select at this time. That
parameter is the FINITE or INFINITE filter. The ECHO function
defaults to the INFINITE option. If you wish, you can use your
mouse to toggle between the FINITE and INFINITE parameter to get
a feel for it. For the purposes of this experiment, select the
INFINITE option if it is not already selected. Using the mouse,
select the OK button. A graphical guage will pop up in the wave
form graph in the lower left corner. This guage is used with
most functions to let us know how the function is progressing. A
percentage completed will also be displayed to the right of the
guage. Depending on the speed of your PC, this function will
take a few seconds.
When the function is completed, the wave form graph will be
redisplayed and SAMPLE1.VOC will be replaced with UNTITLED. This
tells us that the current file has been modified. BLASTER Master
never changes the original file unless you choose to save on top
of it. It is a very good idea to always rename the file unless
disk space is getting low. Working with digital files gobbles up
hard disk space very quickly! BLASTER Master will warn you when
your disk space is marginal.
Select the PLAY function and we will hear what our sound file
sounds like with echo. You can select the PLAY function by using
the mouse or keyboard users can press ALT-P. You should hear a
very noticable echo in the sound file. By using different delay,
mixture and filter combinations you can achieve a wide variety
of effects. I will leave it to you to experiment with these
settings.
Saving the New Sound File
Now that we have applied some echo to our sound file, we need to
save it and try some other functions. We could continue to add
more DSP functions to the sound file. There is no limit to how
many functions can be applied to a single sound file. Later in
the tutorial we will discuss combining functions to achieve some
interesting effects.
Using the mouse, place the cursor over the NEW function and
press the LEFT mouse button. The Save File dialog box will
appear in the center of the wave form graph. The cursor will be
in the file name field of the dialog box. Using the keyboard,
enter:
ECHO1
We could save our file in another format besides VOC. In the
lower right of the Save File dialog is a series of radio buttons
to select the desired format, such a WAV. This dialog always
defaults to the VOC file format. Just below the file name and to
the left are three option buttons. These options can be used to
SAVE the file as named, RETURN TO THE EDITOR and make more
changes or DON'T SAVE and discard the sound file and lose the
changes. For purposes of our experiment, we want to SAVE the
sound file. When you begin experimenting on your own, you will
often choose to not save the sound file to conserve disk space.
BLASTER Master will return you to the File Select dialog box.
You should see ECHO1.VOC included with the other sound files.
The REVERSE Function
Because digital files are nothing more than a series of
amplitude values captured at a constant rate, the playback can
be easily reversed by simply reversing the order of the samples.
In other words, the last sample byte becomes the first sample
byte and the first sample byte becomes the last sample byte. All
the subsequent sample bytes are reversed in this same manner
until the whole file has been processed. This is one of the
easiest of the DSP functions to do. It is also one of the
fastest. No user supplied parameters are required because of the
simplicity of the process. Because of the simplicity of this
function, we will not go over the steps for accessing it. We
will combine the REVERSE function with ECHO for a very
interesting effect a bit later in this tutorial.
Fun with the REVERSE Function
There is not that much practical use for the REVERSE function,
but you can have alot of fun with it. Television evangelists can
spend hours and hours looking for those pesky satanic references
in rock and roll lyrics. Many phrases will make new phrases when
reversed and auditioned with a bit of imagination. The reversed
words tend to be one or two syllable words but they are there
none the less. I have always poked fun at this but maybe there
is something to it afterall... If you reverse Robert Johnson's
1935 song, "Hellhound on My Trail" it seems to very clearly
state, "He's someone that I like!". Blues legend maintains that
Robert Johnson sold his soul to the devil to be the world's
greatest blues singer. Maybe they are right.
Those of us who can remember that Paul McCartney had a band
before Wings may remember that "Number Nine" from The Beatles
White Album song "Revolution Number Nine" played in reverse
sounds like "turn me on, deadman". It does indeed. The British
accent helps though. When I reverse my own Texas drawl saying
"Number Nine" it sounds more like "turn me own, dumb dumb".
Did you know that Johnny Weissmuller's famous Tarzan yell sounds
the same after being reversed? It does. Try it. Who ever created
the original effect spliced the tape onto itself in reverse to
extend the call. Using the ZOOM feature will reveal the actual
point the sounds connect. The warbled yodel in the Tarzan yell
is produced by playing the original vocal at a faster speed and
mixing it back in several times. That explains why neither
Johnny or Carol Burnet could ever reproduce it exactly. Someone
put alot of work into it with tape and scissors!
Another interesting experiment with the REVERSE function is to
record your voice saying your name and then reverse it. Practice
saying your name in reverse until you can record it and reverse
it to produce your name forward again. Whereas this ability may
not help your resume' very much, it is fun for children of all
ages.
Combining the REVERSE and ECHO Functions
This experiment will combine the REVERSE and ECHO functions to
produce a very different type of echo than is found in the real
world. This is only one example of how functions can be combined
to produce some very interesting effects. You will soon be able
to use your imagination to achieve your own special effects. I
also recommend you begin to pay attension to the special effects
in movies and on television. You will begin to recognize how the
sound F/X experts make their magic.
Select and REVERSE the Sound File
Using the same steps to select a sound file as we did earlier in
this tutorial, select the SAMPLE1.VOC file and enter the wave
editor. First we will REVERSE the file. Select the REVERSE
button using the mouse cursor and the LEFT button. A small
dialog box will appear in the center of the wave form graph with
only two options, OK and CANCEL. Choose the OK button and the
sound file will be quickly reversed. Once again the file name
has changed to UNTITLED. Select the PLAY option to audition the
reversed sound file. Did it sound like you expected?
ECHO the Reversed Sound File
We will now select the ECHO function exactly as we did before,
only this time the file is in reverse. Follow the same steps and
parameters as before. For added effect, you can use a delay of
200 milliseconds if you wish. Once the ECHO function is
completed, the echoed sound file will be redisplayed in the wave
form graph. Select the PLAY option again to hear the multi-
processed sound file.
Reverse the Sound File Again!
Once more, select the REVERSE option and process the sound file
for a third time. When the sound file is redisplayed, select the
PLAY option to hear the results of combining these two
functions. Instead of a natural echo, we have the effect of a
"reverse echo". The sounds fade into the original instead of
fading out. This can be very useful for outer space effects and
bizarre Doppler effects.
Saving the Multi-processed Sound File
Using the mouse, place the cursor over the NEW function and
press the LEFT mouse button. The Save File dialog box will
appear in the center of the wave form graph. The cursor will be
in the file name field of the dialog box. Using the keyboard,
enter:
ECHO2
As mentioned earlier, we could save our file in another format
besides VOC. In the lower right of the Save File dialog is a
series of radio buttons to select the desired format, such a
WAV. This dialog always defaults to the VOC file format. Just
below the file name and to the left are three option buttons.
These options can be used to SAVE the file as named, RETURN TO
THE EDITOR and make more changes or DON'T SAVE and discard the
sound file and lose the changes. For purposes of our experiment,
we want to SAVE the sound file. When you begin experimenting on
your own, you will often choose to not save the sound file to
conserve disk space.
BLASTER Master will return you to the File Select dialog box.
You should see ECHO2.VOC included with the other sound files.
You can use the PLAY option from the File Select dialog box to
compare the ECHO1.VOC and ECHO2.VOC if you wish.
Using the PITCH Function
One of the components of a digital sound file is the Sample
Rate. The sample rate is a steady, constant value that reflects
how many samples are played during a single second. A sample
rate of 22khz (twenty-two kilohertz) means that 22,000 samples
are played each second. When the original digital sound file was
sampled (recorded), a measurement of the voltage passing through
the microphone was made 22,000 times a second. Playing back the
file at the same sample rate will reproduce the digital sound
file at the exact same pitch it was originally sampled. If we
increase or decrease the original sample rate during playback
the pitch will change accordingly.
The PITCH function is accessed like the other DSP functions in
BLASTER Master. It is not one of the default functions that
appear when a sound file is first displayed so it is necessary
to use the MORE button. It is also included in the TOOLS under
the Vanishing Menu, as are all the other functions. The PITCH
dialog box uses a rangebar or slider to choose the amount of
pitch change. The first time the pitch is changed the sound file
will be redisplayed and the file name will change to UNTITLED.
All pitch changes to the UNTITLED sound file will be much
faster. Only the header will be changed to reflect the new
sample rate. Do not confuse the PITCH and the RATE functions.
They are very different. We will discuss the RATE function
below.
Handy Tip
When the PITCH function is used the playback speed is also
altered along with the pitch. When lowering the pitch you may
wish to combine it with the FAST function to increase the
playback speed without changing pitch. This is particularly
useful with speech type sound files. The vocal inflection will
sound more natural. The same applies to increasing the pitch.
Use the SLOW function to make the sound file less chattery. Try
applying the REVERSE/ECHO/REVERSE technique along with a pitch
reduction and playback speed increase. This produces an erie,
alien type voice that can be useful for games that you write.
Using the RATE Function
Unlike the PITCH function that merely changes the rate which a
sound file is played back, the RATE function actually changes
the sample rate while maintaining the original pitch. The RATE
function uses a mathematical function known as spline
interpolation. Interpolation can calculate missing samples in
the case of raising the sample rate or determine which samples
to remove or replace in the case of lowering the sample rate.
This function can be very useful for reducing the size of a
sound file without using compression (packing). Many sound files
will sound no different when resampled to a lower rate.
Aliasing
If after using the RATE function to lower the sample rate. the
sound file begins to get a tinny sound, then try again at a
slightly higher sample rate. The tinny sound is called aliasing.
It is produced when the sample rate is not high enough to
capture the higher frequencies accurately. The Nyquest theorum
states that a sound file must be sampled at twice the sample
rate of the highest frequency. In other words, to capture
frequencies up to 11khz requires a sample rate of at least
22khz. Many people falsely believe that a high sample rate will
insure a clear sample with very little hiss or background noise.
The sample rate is used purely to capture frequency range. The
signal to noise ratio is determined by the number of bits used
in each sample. A 16bit file has a theoretic signal to noise
ratio of 96db. An 8bit file can only have a signal to noise
ratio of 48db.
Using the VOLUME Function
Some digital sound files may not be sampled at a audio volume
that suits your purposes. The VOLUME function is used to adjust
the amplitude of digital sound files. Increasing the audio
volume of a sound file will not introduce any new noise to the
signal but it will increase the volume of any noise present.
This is almost never a problem unless the original sound file is
of a very poor quality. The VOLUME function is one of the easier
DSP functions to do. It multiplies each sample byte evenly by a
factor that will increase or decrease the amplitude. It is very
usefull when combined with the MIXER functions.
The VOLUME function is accessed like all the other DSP
functions. It is also available as a block tool and is often
more desirable for reducing noise than is the MUTE block tool.
Two user supplied parameters are required to perform this
function. First, we must tell the the function whether we will
be increasing or decreasing the volume. Enter either an "I" to
increase or a "D" to decrease. Do not use the quotation marks!
Next we must supply the function with the factor in which to
adjust the volume. In the case of decreasing the volume, the
factor must be between 99 and 1. This will lower the amplitude
to that level relative to the original sound file. A sound file
can be increased over a much wider range. The volume can be
doubled by entering a value of 100. This process can be ran
several times if some tweaking is required.
The VOLUME function will recreate the sound file as UNTITLED and
redisplay the processed file like the other functions. Go
through the same steps to save the file as before.
Using the FADE Function
The FADE function is very similar to the VOLUME function.
Instead of applying a constant factor that the samples will be
scaled to, it uses an increasing or decreasing factor to cause
the sound file volume to fade in or to fade out. A FADE IN
assumes you will be starting at the beginning of the sound file.
You can FADE IN from the beginning to approximately half way
into the file. The FADE OUT function assumes that you will be
fading out to the end of the sound file. You can begin the FADE
OUT function approximately half way into the sound file to the
end. This is an extremely usefull DSP function and can be
applyed to almost any digital sound file.
Determining the Fade time
Usually the amount of time to fade can be determined visually by
using the time grid that is displayed in the wave form graph. A
more specific method is to use the mouse cursor to determine the
FADE IN time by moving it over the wave form graph and noticing
the current time as it is displayed to the right of the total
playing time. Another method that can be applied to both the
FADE IN and FADE OUT time window is to use the mouse cursor
combined with the LEFT mouse button to mark a block at the
beginning or ending of the sound file. The playback time for the
block is displayed to the right of the total playback time.
After noting the block time, use the NEW button to exit block
mode and return to function mode. Be carefull to only press the
NEW button once. Otherwise you will be returned to the Select
Soundfile Dialog box. If you are working with an UNTITLED sound
file and you accidentally press the NEW button twice, the Save
Soundfile Dialog box has a Return to Edit button that will put
you back in function mode.
Cross-fading
The FADE function can also be used very effectively with the
MIXER function to apply cross-fading of two files. Cross-fading
occurs when one sound file fades out as another sound file fades
in. Cross-fading is very commonly used in broadcast radio to
segue one song into another. Disk Jockeys use a mixer board
rather than digital signal processing. An example of cross-
fading using BLASTER Master would be to fade out about 4 seconds
of the first sound file and fade in 4 seconds of the second
sound file. Using the MIXER function, mix the second sound file
into the last 4 seconds of the first sound file. Don't worry if
you don't know how to use the MIXER function. That is our next
topic.
Using the MIXER Function
The MIXER function is a very powerful tool in our arsenal of DSP
functions. It literally combines two digital sound files into a
third combined sound file. The combined sound file can then have
another sound file mixed in, and so forth. Each generation will
lose some clarity so there is a limit to how many sound files
can be mixed in and still achieve decent fidelity. You can also
choose the exact point to mix a sound file in using the mouse
cursor, the marker, a certain time into the sound file or a
certain number of samples into the the sound file. One primary
thing you should be aware of is the mixer does not attempt to
adjust the sample rate of the sound file being mixed in if it
does not match the sound file selected for editing. This can
work to your advantage for achieving certain effects. In most
cases you will want to process one file or the other using the
RATE function if the two sound files have different sample
rates. The amplitude or volume can be adjusted for the sound
file being mixed in. The basic use of the MIXER function is
quite simple but getting the sound balance adjusted correctly
and selecting the point to begin the mix will take some practice
and often several attempts to get it just right.
Selecting the Mix File
We begin our MIXER experiment by selecting the original sound
file to be processed. Use the same steps as before to select a
sound file and display it in the Wave Form Graphic Display. When
the MIXER function is selected using either the Function buttons
or from the Tools menu of the Vanishing Menu, the familiar File
Select Dialog box will be displayed across the Wave Form Graphic
Display. The heading of the dialog box will be SELECT SOUND FILE
TO MIX IN. This can be disorienting the first time the MIXER or
INSERT functions are selected. Both functions use the File
Select Dialog box to choose the secondary sound file, so don't
be confused. You are still in Function mode. Select the Mix in
sound file using your mouse or the keyboard just like you would
select any other sound file for editing. (You could also RECORD
a new sound file to Mix in. We will not go into that at
present.) Remember! The MIXER function does not adjust the
sample rate of the sound file being mixed in. If you select a
sound file with a lower sample rate, the mixed in sound file
will playback at a faster rate. If a sound file with a higher
sample rate than the original is chosen, the mixed in sound file
will playback at a slower rate. If the sample rates do not
match, you can always first process one of the sound files using
the RATE function as described earlier in this tutorial. After
selecting the Mix in sound file, the Mix In Volume dialog box
will be displayed.
Choosing the Mix In File Volume
The Mix in sound file can be added at a different volume than
the original sound file. The Mix in Volume has a range of 1 to
200. To use the original volume of the sound files, enter 100 as
the volume. To lower the volume, enter a value less than 100. To
boost the volume, use a value that is greater than 100. If you
are adding background sounds to the original sound file, you
will probably want to use a lower volume than 100. If you are
mixing in a sound file over a bed or background sound file, then
you may wish to boost the Mix in sound file. In either case, you
may wish to experiment and apply the mixing more than once.
Remember to use a different name each time you save the
processed sound file. You will have to enter the Mix in Volume
value using the keyboard.
Choosing the Mix In Point
After entering the Mix in Volume, a dialog box will be displayed
for you to select how you want to select the point to begin
mixing. The Mix in Point can be selected using your MOUSE
cursor, the MARKER, TIME into the original sound file or SAMPLES
into the original sound file.
Using the MOUSE Option
Choosing the MOUSE option will cause the Function buttons to
disappear and a graphical box will appear where the buttons were
before. Move the mouse cursor over the Wave Form Graphic to the
point you wish to begin the mix in and press the LEFT mouse
button. If you wish to mix in from the beginning of the original
sound file, move the mouse cursor as far to the left as it will
go before you press the LEFT mouse button.
Using the MARKER Option
Choosing the MARKER option will begin the mix in from the point
that the marker is set. If the MARKER is not set, the process
will abort. Using the MARKER is a very handy method for
preselecting the mix in point. Remember, the MARKER can be set
by pressing the RIGHT mouse button with the mouse cursor over
the Wave Form Graph. The MARKER appears as a white triangle just
below the Wave Form Graph.
Using the TIME Option
The TIME option is a very accurate method of selecting the mix
in point. It offers selectability up to 1/1000th of a second.
The time value is entered using the keyboard.
Using the SAMPLES Option
The SAMPLES option allows you to select the mix in point at a
sample level. It is also a very accurate method of selecting the
mix in point. Both the TIME and SAMPLES options will be used in
special cases. The MARKER and MOUSE options will usually be more
than adequate for general use.
Creating Special Effects with the MIXER Function
The MIXER function can be used to create many special effects.
Longer echo delays can be processed using the MIXER function.
You can not mix a sound file onto itself, but the SAVE AS...
option can be quickly selected from the Vanishing Menu's FILE
menu to make a copy of the original sound file. Some interesting
speech effects can be created by using several DSP functions to
generate a very altered speech file. Then overlay the original,
unprocessed speech file to add clarity back in. Like all the DSP
functions in BLASTER Master, you are only limited by your
imagination.
Using the INSERT Function
The INSERT function uses the same basic user interface as the
MIXER function. There is no VOLUME parameter required. Unlike
the MIXER function, INSERT will adjust the sample rate or the
insert sound file to match the original sound file. It will also
adjust the number of channels of the insert file to match the
original sound file. In other words, a mono sound file inserted
into a stereo sound file will be coverted to a two channel sound
file. A slight delay is added to the converted channels to
simulate stereo and add more depth. If a stereo sound file is
inserted into a mono sound file, the two channels of the stereo
sound file will be compared and mixed where needed. The INSERT
is a very fundimental DSP function. You will find yourself using
it quite a bit.
Using the SLOW Function
The SLOW function is a tool for very specialized use.
Essentially, it slows the playback speed of a digital sound file
without effecting the pitch. The playback speed will be
approximately half of the original, depending on the sound file
used. It requires no input parameters. The function itself is a
fairly involved process. It scans through the file and
duplicates very small segments of the waveform to extend the
time. It uses some inteligence to find the segments and then
cross-fades the splice points. It works best with simple speech
tracks but can also be used effectively with more complex sound
files like music. Musicians will find it particularly useful for
slowing down solos for closer study. Hardware devices to perform
the same function, such as the SloMo, cost several hundred
dollars and are limited to a few seconds. The SLOW function can
also be very useful when used with the PITCH function. When
increasing the PITCH, use the SLOW function to give the speech a
more natural and less chattery sound.
Using the FAST Function
We could not have a SLOW function without a FAST function as
well. The FAST function is a simpler process and does allow for
user selectable effect. Choosing the FAST function displays a
dialog box with a rangebar or slider for selecting how much to
speed the playback. Like the SLOW function, it works best with
simple speech type sound files but music can also be processed
effectively. The function works by removing minute segments of
the waveform and cross-fading the splice point. The FAST
function also works well when used in conjunction with the PITCH
function. When using PITCH to lower the sound file pitch, apply
the FAST function to give the resulting sound file a more
natural sound. Both the FAST and SLOW functions are interesting
effects and worth some time experimenting with.
Using the VOCALS Function
The VOCALS function requires a stereo sound file. It can be used
to eliminate the vocals from music type sound files. The results
will vary from sound file to sound file. The process works by
inverting one channel of a stereo sound file and mixing it into
the remaining channel to produce a mono file. All of the
waveforms that are in the center of the stereo space are
canceled out. Vocals are usually mixed in the center so they are
usually canceled out. Unfortunately the solos are also usually
mixed in the center so they are also canceled out. As mentioned
above, the results are determined on how the original stereo
recording was mixed and balanced. You can sometimes improve the
results sometimes by tweaking the balance of the source channels
during recording. The VOCALS function does work just as well as
the $350 devices that are sold in magazines. There are no user
supplied parameters required for this function. It is alot of
fun and worth experimenting with.
Using the PANNING Function
The PANNING function also requires a stereo sound file. PANNING
causes the volume to pan from one stereo channel to another. The
user may select a left channel to right channel pan or a right
channel to left channel pan. It is a very simple process can be
very effective and useful. The PANNING function can only be
accessed from the TOOLS menu of the Vanishing Menu.
Using the SILENCE Function
The SILENCE function will insert silence bytes into a stereo or
mono sound file. It is very usefull for extending the playback
time for syncing with a graphic file, such as an FLI file. It
can also be indespensible when mixing multiple files together.
Using the MAKE MONO Function
The MAKE MONO function requires a stereo sound file. It will
convert the stereo file to a mono sound file. This is very handy
for reducing the size of a file by half or for users with a mono
only soundcard.
Using the HISS Function
The HISS function can be more accurately described as a noise
gate filter. There is a very popular utility with a similar
name. I had several requests from my registered users to add
this function, so I retained the name. It essentially replaces
sound bytes below a certain amplitude with silence bytes. It is
very usefull with spoken word sound files to remove any
background noise.
Using the PACK/UNPACK Functions
The PACK/UNPACK functions only work on mono sound files. Packing
involves applying a real-time compression known as ADPCM
(Adaptive Delta Pulse Code Modulation). It is not a lossless
compression and should only be used when absolutely necessary.
Depending on the amount of compression applied, the loss in
clarity will be quite apparent. An example of 2:1 compression is
as follows:
The first sample byte is preserved uncompressed as the
"reference sample". The difference between that sample value and
the next sample value is stored as a 4 bit value in the next
byte. Each subsequent sample is then stored as the difference
between the last value as a 4 bit value. Each byte after the
first sample byte then contains the value of two sample bytes.
Because waveforms follow a rising and falling pattern, an
adaptive difference is applied to help minimize the amount of
clarity loss. This adaptation is different for one ADPCM
algorythmn to another.
The UNPACK function will only work with a previously packed
sound file. It retunrs the sound file to an uncompressed format
although it can not restore the lost resolution of the original
sound file. It is necessary to UNPACK a packed sound file before
most of the DSP functions can be used.
Compression works best with speech type sound files. Music type
sound files will usually have the pitch and frequencies altered
too much for any practical applications. Once again, do not use
compression unless absolutely necessary.
Using the SCOPE Function
The SCOPE function is not actually a DSP function at all. It is
very entertaining and educational and was included for those
purposes. It can be very useful for adjusting the input volume
of your input source. That is the reason it is included in the
RECORD dialog functions. The SCOPE function can be exited by
pressing any key or clicking either mouse button. Just connect a
microphone, select the SCOPE function and speak into it. Sound
Blaster Pro users will have the option of selecting the input
source (Microphone, Line In or CD Audio). The input source can
be selected from the RECORD function. You will get to see your
voice as well as hear it. Children particularly love the SCOPE
function.
The SCOPE function uses the direct mode of sampling from the ADC
(Analog to Digital Converter). The sample rate is set at the
highest number of cycles your processor can perform. The
smoothness of the waveforms are achieved using two page
animation mode.
Using the BLOCK MODE Functions
We have seen how processes can be performed on an entire digital
sound file. We have also combined several functions to create
new and exciting special effects. Now it is time to explore some
of the specific editing functions and block tools. There will
usually be sections of the sound file at the beginning and end
that need to be removed. There could also be noise or unwanted
vocal pauses like "ughs" that can be cut from the sound file. A
sound file may contain a segment that needs to be moved or
copied to another portion of the file. We will go over each
editing function in detail in this section of the tutorial.
Entering BLOCK MODE
BLOCK MODE can only be entered by using a mouse. There is no
keyboard equivalent to select a section of a sound file. To
select a section of a file, move the mouse cursor over the
waveform graph and press the left mouse button once. A blue
vertical line will appear at the point where the mouse cursor
was. The DSP Function buttons will disappear and you will be
prompted to select the next section of the block. You can select
from either side of the first mark. Press the left mouse button
once again to select the next section of the block. The block
selected will be enclosed within a blue box. The Edit Mode
Function buttons will appear where the DSP Function buttons were
before. The size in bytes of the block will be displayed next to
the file size. The playing time of the block will be displayed
next to the playing time of the full file.
Important Tip!
Always select more of the file for your first (primary) block
than you want. Once a block is marked you can not use the mouse
to move the blue lines, although you can select another block
within the original block after selecting the ZOOM function. The
ZOOM function will allow you to very accurately select exactly
the section of the file you wish to modify. You can always use
the UNZOOM function to return back to your previous block if you
want to try again. With a very little bit of practice, you will
soon be able to select exactly the block you need.
The BLOCK MODE Vanishing Menu
The Vanishing Menu options are different in BLOCK MODE. It is
accessed the same way but the sub-menu options have changed:
BLOCK
These menu options allow you to select a NEW block, CUT the
block from the sound file, SAVE the block as a new sound file,
MOVE the block to a new location in the sound file, make a COPY
of the block in a new location in the sound file or to PLAY the
block.
OPTIONS
These menu options allow you to LOOP play the block or sound
file over and over again and choose whether the PLAY function
will only play the selected block or the entire file.
TOOLS
These menu options correspond to the same DSP functions as the
TOOLS button that appears on the lower screen. We will discuss
them in detail later.
HELP
This menu option displays a simple online help screen. The BLOCK
MODE functions are described in more detail than just the button
labels. This is a handy reminder from time to time if there are
features that you have not used very often.
The BLOCK MODE Functions
The PLAY Function
The PLAY function in BLOCK MODE usually plays the selected block
only. This is very useful for verifying that you have exactly
marked the section you want. You can play the entire file by
choosing the Options sub-menu from the Vanishing Menu and set
playback to ALL.
The TOOLS Function
This function displays a menu of DSP function tools that will
modify the selected block. Some of the tools are much the same
as the DSP functions for modifying the complete file but others
are more specific to a block of sound. These unique functions
can always be applyed to the entire file by selecting a block
large enough to contain the sound file. The BLOCK MODE tools
are:
LOOP
This function will repeat the block in the soundfile upto 10
times. This function is very handy for making a sound stutter or
to create a pad for later mixing into another file. The number
of loops can be selected using a sliding range bar with options
from 2 to 10. This function will increase the size of the file
accordingly.
MUTE
This function will replace the selected block with silence. This
can be very useful for removing extraneous sounds without
changing the playback time of the sound file.
REVERSE
This function will reverse the playback of the block.
PITCH
This function will raise or lower the pitch of the selected
block. The amount of pitch adjustment is based on a percentage
of the original sample rate. The adjustment is selected by using
a sliding range bar.
ECHO
This function will echo the selected block. The input parameters
are the same as the DSP Echo function for processing the whole
soundfile.
VOLUME
This function will increase or decrease the playback volume of
the selected block. The input parameters are the same as the DSP
Volume function for processing the whole soundfile. This
function is often more desirable for removing background noise
than the MUTE function. Whereas the MUTE function is dead
silence, the VOLUME function can be used to reduce the
background sound and retain a certain amount of ambience.
ACCELERATE
This function will gradually increase the pitch and playback
speed of the selected block.
DECELERATE
This function will gradually decrease the pitch and playback
speed of the selected block.
The CUT Function
This function will remove the selected block from the sound
file. It is very useful for removing unwanted sections at the
beginning and ending of a sound file. It can also be used to
remove vocal "ughs" and such and to shorten the gaps between
words and sentences.
Handy Tip
The CUT funtion will use a DOS trick to shorten the length of a
file when you are cutting the far right section of an UNTITLED
sound file, i.e., one that has already been edited at least
once. The block can not be ZOOMed to use this fast method. If
you want to remove sections from both the beginning and end of a
sound file, remove the beginning section first! This will create
an UNTITLED sound file and make cutting the end of the sound
file much faster.
The NEW Function
This function will allow you to select a new block for
modifying. The blue box will disappear and you will be returned
to the DSP functions for processing the whole sound file.
The ZOOM Function
This function will display the selected block across the
Waveform screen graph. Once a block has been ZOOMed, you may
select another block until the display resolution reaches 1:1.
BLASTER Master supports upto 64 ZOOM levels.
The UNZOOM Function
This function will return the screen to the previous resolution
before the last ZOOM. By combining the ZOOM and UNZOOM
functions, you can very accurately select exactly the section of
the sound file to be modified.
The SAVE Function
This function will save the selected block as a new sound file.
The original sound file is left exactly as it was. You will then
be prompted to return to editing the original sound file or to
edit the new saved block.
The MOVE Function
This function will move the selected block to a new location
within the sound file. You can have alot of fun altering speech
files and such by moving the words around to make new sentences.
The COPY Function
This function will copy the selected block to a new location
within the sound file. The original block is left intact. This
is a very handy function for making RAP type sound files. NOTE:
This function is only available from the BLOCK sub-menu of the
Vanishing Menu.
Exiting BLOCK MODE
Clicking the NEW button will exit BLOCK MODE and return you to
the DSP Functions. You also have the keyboard options of using
the ESC key or pressing ALT-N. This is also the method for
selecting a NEW primary block for modifying.
Summary
We have now covered the functions and techniques needed to get
the most from BLASTER Master. With a little practice you will
develop the skill to manipulate your sound files like an expert.
With a little imagination, the possibilities are endless!
Because I am constantly adding new features and improving the
interface, BLASTER Master will always be the most advanced
digital editor available.
Please refer to the BMASTER.DOC file for a listing of BBSs and
online services where you can find the latest update of BLASTER
Master. It is also available on hundreds of other BBSs around
the world. I appeciate any help you can offer by uploading
BLASTER Master to any BBSs you can!
Thank you for using my software.
BLASTER Master
(c) Copyright 1993 by Gary Maddox, all rights reserved.