Loop Tuner |
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From the View menu, choose Loop Tuner to open or close the Loop Tuner window. You can use the Loop Tuner to adjust the starting and ending points of a loop to create smooth transitions.
The Loop Tuner allows you to view both loop endpoints at once. The left-hand side of the Loop Tuner window shows the end of the loop, while the right-hand side shows the start of the loop. A seamless loop will not have any discontinuities; the waveform should look smooth as it goes from the end of the loop back to the start.
You
must define at least one loop before using the Loop Tuner. For more
information about creating loops, click here.
Creating natural-sounding loops requires experimentation. Many factors can cause pops and glitches, but the following guidelines will help you to create loops with less trial and error.
It's most common for the endpoints of a loop to occur at zero-crossings.
If the slope of a waveform changes drastically, an audible pop will be produced.
The overall loudness within ~100 ms of the endpoints should be equal.
If the loop is shorter than ~50 ms (1/20 Hz), you will most likely create a loop with a pitch not equal to the sample pitch.
You
can experiment with pitch-tuning by creating short loops with a
length of 1/frequency. For example, if your had a sample pitch of 440
Hz (A5 on the MIDI keyboard), you can make the loop 2.27 ms. Pitched
loops, however, do not sound like the original sample.
Click the Play Pre-Loop
button
to play the sound data before the selected loop.
Click the Play Loop
button
to play the selected loop. You can use the Loop Tuner to tune the
loop in real-time during playback.
Click the Play Post-Loop
button
to play the sound data after the selected loop.
When your Sample Type is Sustaining
with Release, you can click the Loop
Select button
to switch between the sustaining and release loops in the Loop Tuner.
The button will display an S when the sustaining loop is displayed and an R when the release loop is displayed.
The Loop End Position
and Loop Start Position
boxes
display the current positions (in samples) of the endpoints. Use the
spin controls to adjust the end points.
Each loop end window includes buttons to move the loop endpoint to the next or previous zero-crossing:
Click the Zero
Crossing Left button
to move the endpoint to the previous zero-crossing.
Click the Zero
Crossing Right button
to move the endpoint to the next zero-crossing.
To
configure the zero-crossing finders, choose Preferences
from the Options menu and click the Editing
tab. You can modify the Snap
to zero-crossing slope, Zero-cross
scan time, and Zero-cross
level threshold settings to determine how Sound Forge locates
zero crossings.
Click the Lock
Loop Length button
if you want to shift a loops position without changing its
length. When on, any operation you use to change a loop point affects
both the start and end of the loop, therefore keeping the loop length constant.
This
button also controls the Lock
Loop/Region Length command on the Options menu.
Loop points are automatically saved when you save your sound file in .wav, .sds, .smp, .dig, .pat, and .air file formats. You can disable the saving of loop points when saving to the .wav format by clearing the Save Sampler Information in file check box on the Save As dialog.