Steinberg Cubase SX/SL 3 Operation Manual

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4.Select the Warp Samples tool (the arrow and clock button) on the 
Sample Editor toolbar.
A grid appears in the waveform display, and warp tabs are automatically added at the 
start and end of the audio clip. These are locked and cannot be removed. 
The Warp Samples tool.
For aligning the tempo you should use Bars and Beats as the ruler 
resolution. When you place the mouse pointer in the waveform display 
it changes to a clock with arrows on either side, and a vertical line in 
the middle which represents the pointer. When you move the pointer 
in the waveform window it shows the position in bars, beats and ticks 
as well as in seconds.
5.Line up the audio file so that the first beat of the first bar (in the audio 
event) starts on the first beat of a bar in the project.
If the audio file doesn’t start on a downbeat you can use the Event Start handle in the 
Sample Editor and adjust the position in the Project window so that the first downbeat 
in the sample is aligned with the first beat of a bar in the grid.
Now the musical first downbeat should be aligned with the first beat of a bar in the 
project. The next step is to see where the first warp tab needs to be added. It may be 
useful to hear the metronome click to determine when the tempo of the audio clip drifts 
from the project tempo. To hear the metronome you have to activate Click on the 
Transport panel and play back using the transport controls.
6.Play back the audio file, either by auditioning in the Sample Editor or 
from the Transport panel, and see (and listen for) where the first beat 
of a bar in the audio event does not match the corresponding ruler po-
sition in the project.
If you find it difficult to pinpoint an exact position in the audio event you can switch to 
the Scrub tool and/or zoom in the view. Switch back to the Warp Samples tool when 
you have found the position.  
						

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7.In our example the first beat of bar 3 in the audio event is slightly offset 
from the corresponding grid position and thus needs to be moved 
back a bit.
The arrow points to the third downbeat in the audio event.
8.Place the pointer at the position of the first beat in the audio event and 
click and hold.
When you click a warp tab is added.
9.With the mouse button still pressed, drag the warp tab so that the po-
sition lines up with the first beat of the bar in the ruler.   
						

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10.Release the mouse button.
Now the first beat in the audio event is perfectly aligned with the corresponding posi-
tion in the project! 
•If you prefer, you can first add warp tabs at the relevant musical posi-
tions and change their positions later – see page 434.
Beside the warp tab handle in the ruler, a number is shown. This num-
ber indicates the warp factor, i.e. the amount of stretch. Warp factor 
numbers higher than 1.0 indicate that the audio region preceding the 
warp tab is expanded and will play back slower. Warp factor numbers 
lower than 1.0 indicate that the audio region preceding the warp tab 
is compressed and will play back faster. 
11.Continue to use the same general method to align the first beat in 
each bar to the corresponding ruler position.
You only have to add warp tabs where the downbeat in the audio file drifts from the 
ruler position, and/or if you want to fixate a warp tab so that it is not moved when edit-
ing other points. 
When you are done, the previously varying tempo of the audio event will 
be metronome steady and will adapt to any tempo in Cubase SX/SL.
This example illustrates the general methods of using warp tabs and 
the Warp Samples tool. But you can of course use warp tabs for other 
operations than aligning downbeats to grid positions. With the Warp 
Samples tool you can literally stretch any region within a sample to 
any position!  
						

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Editing warp tabs
Moving the destination position of existing warp tabs
•To move an anchored destination position of a warp tab (and thus 
stretch the audio), select the Warp Samples tool and position the 
pointer on the Warp line in the waveform so that the line in the middle 
of the pointer becomes blue. Then click and hold to move the position 
of the warp tab. 
Moving the source position of existing warp tabs
•If you simply wish to move the position of a warp tab without stretch-
ing the audio, click and drag the warp tab header in the ruler.
Deleting warp tabs
•To delete a warp tab, press [Shift] so that the pointer becomes an 
eraser and click on the warp tab.    
						

							CUBASE SX/SLAudio warp realtime processing19 – 435
Showing/hiding warp tabs
When you are using other Sample Editor tools than the Warp Sam-
ples tool you can decide whether to show or hide warp tabs by click-
ing the Show Warp Tab button.
Unstretching audio files
By selecting “Unstretch Audio” from the Realtime Processing sub-
menu on the Audio menu, all time stretching (by sizing or by warp 
tabs) can be removed.
Whether the “Unstretch Audio” menu item is available depends on 
whether the time stretching was applied on the event or clip level:
•If you sized an audio event in the Project window using the “Sizing 
Applies Time Stretch” tool (see page 134), you can undo the time 
stretching by selecting the event in the Project window and then ap-
plying “Unstretch Audio”.
This will remove all time stretching and warp tabs.
•If you added warp tabs to a clip in the Sample Editor, you have to 
open the audio file in the Sample Editor to be able to invoke the “Un-
stretch Audio” function.
Selecting “Unstretch Audio” will then remove all warp tabs in the clip, but not any time 
stretching in the Project window (on the event level).
• Note that if Musical Mode is activated, realtime stretching is still active. 
When you have entered a tempo and/or length using the Audio Tempo 
Definition tool, this information is saved for the source clip.
Warp settings
The “warp settings” pop-up menu, which is located on the Sample 
Editor toolbar, contains various presets affecting the realtime time 
stretching sound quality. These presets have self-explanatory names 
like “Drums” and “Mix”, where the parameters involved have been op-
timized for the corresponding type of audio material.   
						

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Advanced settings
If you select the Advanced menu item, a dialog opens where you can 
manually change the three parameters that govern the sound quality 
of the time stretching:
Creating warp tabs from hitpoints
You can also create warp tabs from hitpoints selecting “Create Warp 
Tabs from Hitpoints” on the Audio menu – Realtime Processing sub-
menu. This can be useful when applying Audio Quantize, see below.
For descriptions of how hitpoints are created and edited please refer 
to the chapter “Working with hitpoints and slices”.
Parameter Description
Grainsize The realtime time stretching algorithm splits the audio into small 
pieces called “grains”. This parameter determines the size of the 
grains. For material with a lot of transients you should use low Grain-
size values for best results. 
Overlap Overlap is the percentage of the whole grain that will overlap with 
other grains.
Variance Variance is also a percentage of the whole length of the grains, and 
sets a variation in positioning so that the overlapping area will sound 
smooth. A Variance setting of 0 will produce a sound akin to time 
stretching used in early samplers, whereas higher settings will pro-
duce more “smearing” effects but less audio artefacts. 
						

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Quantizing audio
You can use realtime time stretch to quantize audio. This is achieved 
by using hitpoint detection and adding warp tabs at the positions of 
each detected transient in the audio clip. When you apply audio quan-
tize the warp tabs stretch the detected “hits” to the grid positions the 
selected quantize-grid is set to. Warp tabs that are not quantized will 
be removed.
The quantizing can either be applied by automatically creating warp 
tabs at the position of existing hitpoints, or you can first create hit-
points, then create warp tabs from these before finally applying the 
quantizing.
For descriptions of how hitpoints are created and edited please refer 
to the chapter “Working with hitpoints and slices”.
In the following description we shall apply Quantize Audio after first 
creating hitpoints, and then creating warp tabs from these. 
1.Open the audio clip in the Sample Editor, specify the length or tempo 
with the Audio Tempo Definition tool selected, and activate Musical 
mode.
2.Calculate hitpoints in the audio event using the normal methods, but 
don’t create slices.
Note that if Q points are used (see page 456), the quantizing will be applied to the po-
sition of the Q point. Also note that when creating hitpoints for audio quantizing – as 
opposed to for creating audio slices – it is not necessary to have hitpoints at all “hits” 
in the sample. You might just want to quantize a section of an audio clip, and leave the 
rest unprocessed. 
3.When you have finished setting hitpoints, select “Create Warp Tabs 
from Hitpoints” from the Audio menu - Realtime Processing submenu.
4.Close the Sample Editor and select the audio event in the Project 
window. 
						

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5.Select a quantize resolution from the Quantize Type pop-up, e.g. 1/8.
Here is a section of the sample before applying Quantize Audio. The hitpoints are 
not on exact grid positions.
6.Select “Quantize Audio” from the Audio menu – Realtime Processing 
submenu.
Now the audio event is quantized by applying time stretch.
7.Open the audio event in the Sample Editor, and either select the Warp 
Samples tool or activate the “Show Warp Tabs” button on the toolbar.
Warp tabs have automatically been added at the hitpoint positions needed to quantize 
the audio to the set resolution.
Here is the same audio event after applying Quantize Audio with a 1/8 quantize 
resolution. The hitpoints are now quantized (or stretched) to exact grid positions.
•To remove the quantizing from an audio clip, select “Unstretch Audio” 
from the Realtime Processing submenu on the Audio menu.    
						

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Quantizing without hitpoints
It is also possible to apply Quantize Audio without creating hitpoints 
first. Although this method is quicker, it is in most cases better to cal-
culate hitpoints using the normal method, as this gives you more con-
trol over where the warp tabs will end up. 
•If you apply Quantize Audio to a selected audio event after just having 
set the length or tempo, the whole event will be quantized. 
Hitpoints are detected automatically, using the current settings set up in the Hitpoints 
Detection dialog. Warp tabs – not hitpoints – are created at each “hitpoint” found dur-
ing the process.
Realtime pitch shifting of audio events
Audio events can be pitch shifted in real time just like MIDI events. 
The process is very simple:
1.Select one or several audio events in the Project window.
Audio parts can not be transposed.
2.Open the event info line.
3.Set a value in the Transpose field to the far right on the info line.
The value range is up/down two octaves in semitone steps. 
4.Press [Enter].
All selected audio events are now transposed to the set value using pitch shift. The 
same general rules apply as for other event editing on the info line, see page 100.
•You can also fine tune selected audio events in cent (100th of a semi-
tone) steps by entering a value in the Finetune field to the right.
Audio and MIDI events can not be transposed simultaneously.  
						

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Freezing the realtime processing
You can “freeze” any realtime processing at any time. This can be done 
to serve two purposes; to conserve CPU power, and to optimize the 
sound quality of the processing. 
•Select the audio event(s) that you wish to process and select “Freeze 
Timestretch and Transpose” from the Audio menu - Realtime Pro-
cessing submenu.
You should also use this function before applying any offline processing. When the 
freeze processing is applied, a copy of the original file is automatically created in the 
audio Pool so that the original audio clip remains intact.
Selecting an algorithm for the freeze (Cubase SX only)
When you freeze the realtime processing you can use the MPEX 2 
algorithm to process the audio, which may produce better sound 
quality than the realtime processing. Proceed as follows:
1.Select the audio event(s) that you wish to process.
2.Select “Freeze Timestretch and Transpose” from the Audio menu – 
Realtime Processing submenu.
A dialog appears where you can select an algorithm for the process-
ing. You can either select the MPEX 2 algorithm, which will produce 
the highest sound quality, or the Realtime algorithm which is much 
quicker but will not improve the audio quality of the processing (al-
though it will lessen the CPU load).