MACKIE Pro Audio Lab - Manual (Page 22)

User’s Guide
The Oscillator
Oscillator Screen
The oscillator has many uses in sound testing, as it can zero in on a specifi c fre-
quency and generate a constant steady tone. For example, the sine wave, having no
harmonic content, is very useful in determining distortion in a signal that can cause
very apparent changes in tone quality.
Level
Use your mouse to select an output level ranging from off to 0 dB.
Waveform Type
This lets you select the type of waveform to generate as your audio signal. The oscil-
lator can generate Acuma (three harmonics), sine, saw tooth, inverted saw tooth and
three ‘square’ waveforms. The default is a sine wave, but you can select other wave-
forms using the up and down arrows, or by grabbing the graphic and moving it left or
right.
Course
With a range of 15.6 Hz to 20.2 kHz, the Course control enables you to “ball-park” a
particular frequency range, prior to using the Fine control.
Fine
Once you have selected a Course frequency range, you can use the Fine control to
fi ne-tune your frequency to an exact setting.
Tip: A good way to approach this is to set your Fine control to its default (control/
click). Use the Course control to hone in on the frequency, and then use the Fine
control to achieve a desired setting. You can save your customized settings using the
Save User Preset in the drop-down menu.
Delay
You can offset your signal, one sample at a time, by adjusting the Oscillator Delay to
add or subtract samples in the right or left channel of your source. Use your mouse
to adjust the Delay knob or use the up/down arrows. This is useful for identifying
phase problems in your source signals. Once you have identifi ed how much adjust-
ment is needed, you can correct the phase by make adjustments using the D8B
Channel Delay.
Tip: Using the Delay feature in Pro Audio Lab does not adjust the delay in your signal.
Remember, it’s for identifying a problem only. Use the Channel Delay feature in the
D8B to make sample changes.
Start
Left-click to start the Oscillator, click again to stop. Right-click to play a momentary
tone burst for as long as you hold down the button.
Level Start Wave Type Waveform
Graphic
Coarse Fine Delay