Eventide SplitEQ Changed Mixing and Mastering User Guide
- June 5, 2024
- Eventide
Table of Contents
SplitEQ Changed Mixing and Mastering
User Guide
Copyright 2022, Eventide Inc.
P/N: 141362, Rev 2
Eventide is a registered trademark of Eventide Inc.
The SplitEQ product utilizes Eventide’s Structural Split technology which is
covered by United States
Patent No. US 10,430,154 B2.
AAX and Pro Tools are trademarks of Avid Technology. Names and logos are used
with permission.
Audio Units and macOS are trademarks of Apple, Inc.
VST is a trademark of Steinberg Media Technologies GmbH.
All other trademarks contained herein are the property of their respective
owners.
Eventide Inc.
One Alsan Way
Little Ferry, NJ 07643
201-641-1200
www.eventide.com
About This Product
SplitEQ is a mixing/mastering EQ that enables you to surgically address common
equalization problems, even in a complex mix. Eventide’s patented Structural
Split™ technology splits the incoming audio into Transient and Tonal signals:
the rapidly changing parts of the input signal are identified as Transient,
while the remaining, sustaining elements are considered Tonal.
Once the signals are split, you can apply equalization and pan separately to
each.
This is useful because many tough EQ problems can be formulated as “I want to
do X but without doing Y.” For example: “I want to increase the low thud of
the kick drum,
but a low-shelf boost will also make the sound muddy.” In split, this problem
is easy to solve: simply apply a low-shelf boost to only the Transient signal.
We think that as you learn to use SplitEQ, you will be delighted to discover
how many common EQ problems it can solve, as well as new creative
possibilities.
Introduction
The plugin window for SplitEQ is divided up into five major sections:
| Preset Bar | Presets, Undo/Redo, A/B Comparison, Info, and Zoom. |
|---|---|
| Plot | Graphical EQ curve editor. |
| Band Editors | Adjust EQ and Pan controls. |
Structural Split
Controls| Fine-tune SplitEQ’s Transient and Tonal detection algorithm.
Master Controls| Metering, Spectrum Analyzer, and Master Controls.
Control Scheme
Under the hood, SplitEQ operates two EQs in parallel, one for the Transient signal, and one for the Tonal signal. This allows you to adjust Transient or Tonal signals independently or together. Because there are twice as many EQs, there are also twice as many controls and curves on the plot. Consequently, SplitEQ provides linked controls for adjusting Transient and Tonal values together and uses color-coding to show which signal a control affects.
- Green controls apply only to the Transient signal.
- Blue controls apply only to the Tonal signal.
- White or Gray controls apply to both signals.
Similarly, green curves on the plot indicate the Transient EQ curve, while blue curves indicate the Tonal EQ curve. White indicates portions of the EQ curves where Transient and Tonal are the same. The color-coding scheme also applies to the metering and the spectrum analyzer.
The EQ Plot
You can adjust the gain, frequency, and Q for each band directly on the EQ
Plot by clicking and dragging on the band’s handle(s) or on or near the band’s
highlighted area.
When Tonal and Transient gains are the same, a white (Both) handle is shown
with colored pull tabs for the Transient and Tonal handles. When the handle is
white the band is behaving just like a normal parametric EQ band; dragging on
the handle or band will adjust Transient and Tonal settings together.
Dragging on one of the pull tabs splits the handle so that you are now
affecting only the Transient or Tonal portion. Separate handles are shown for
Transient and Tonal, and Both handles disappear.
The blue handle represents the Tonal settings, and the green candle represents
the Transient settings. Dragging anywhere other than the Transient or Tonal
handle will move both handles in parallel, maintaining their initial offset.
To bring the handles back together, double-click on the Transient or Tonal
handle and the other handle will snap to it.
The following table shows the mouse interaction modes for SplitEQ’s plot:
For an illustrated overview of how the band handles work, follow the tutorial when you first launch the plugin. This tutorial is also accessible under the “i” (Info) menu in the menubar.
Band Editors
The Band Editors section is located underneath the plot. It contains two
panels, EQ and Pan, which can be accessed through the EQ and Pan buttons in
the lower left corner.
Similar to the plot, the controls in the Band Editors also support linked
edits.
The following table shows the mouse interaction modes for SplitEQ’s linked
text sliders:
Controls
Reset All
| Reset All
---|---
Collapse/Expand
| To reduce the size of the band editors, click on the collapse icon. When the
band editors are collapsed, clicking the expand button will restore them to
their original size.
EQ/Pan (Mono/Stereo and
Stereo instances only)| Switches view from EQ values to panning values and
vice versa.
EQ
Each EQ band’s parameters are displayed on this panel.
The first band and last band are dedicated highpass and lowpass filters with
independent Transient and Tonal cutoff frequencies.
The numbered bands (1-6) can be assigned to different filter types. These
bands each use a single frequency for the Transient and Tonal filters.
Band Controls
Active| Enables/disables processing for the band. Disabled bands will not be
shown on the plot unless they are soloed.
---|---
Type
(bands 1-6 only)| Selects the type of filter for bands 1-6.
The available types are:
• Low Shelf
• Peak
• Notch
• High Shelf
• Tilt Shelf
• Bandpass
Slope| Selects the slope of the filter in dB/oct.
Solo| Solos the band. When you mouse over the headphone icon a popup appears
which allows you to select the source for the
solo: Transient, Both, or Tonal.
Frequency| Sets the frequency for the band. The Highpass and Lowpass bands
have separate Transient and Tonal frequencies. The numbered bands (1-6) use a
single frequency value which applies to Transient and Tonal.
Gain| For peaking and shelving filters, this sets the individual Transient and
Tonal Gains of the band. These values can be moved together or separately.
Linked adjustments preserve any offset between Transient and Tonal Gain.
Split Source
(Notch filter only)| Selects which signal the notch applies to Transient,
Both, or Tonal. This appears in place of gain controls for the Notch filter
type.
Q| This sets the Transient and/or Tonal Q factor of the band.
These values can be moved together or separately. Linked adjustments preserve
the ratio between Transient and Tonal Q.
Pan
(Available in Mono/Stereo and Stereo instances only.)
Each band’s stereo positioning details are displayed on this tab. This panel is not available for mono output instances of SplitEQ.
Controls
| Pan Mode | Switches between Left/Right and Mid/Side panning modes. |
|---|---|
| Pan | This pans the effect of the band’s EQ for both the Transient and Tonal |
signals. These values can be moved together or separately. Linked adjustments
preserve any offset between Transient and Tonal Pan.
Mid/Side| This adjusts the stereo width of the band’s Transient and Tonal
signals. These values can be moved together or separately.
Linked adjustments preserve any offset between Transient and Tonal Mid/Side.
The Pan Mode and Mid/Side controls are only available in stereo instances of the plugin because Mid/Side processing requires a stereo input source.
Split
The Structural Split™ divides the incoming audio signal into Transient and
Tonal signals.
It does this by looking for regions of relative stability in terms of time and
frequency and considers those to be Tonal. Subtracting those regions from the
input, what remains is Transient. The advantage of this approach is that,
unlike compressors or other dynamics-based tools, it is not level-dependent.
After all, in the real world transients can be loud or soft.
The Transient and Tonal signals are complementary: if you sum them back
together, they perfectly reconstruct the incoming signal. Put another way, any
part of the sound that is not considered Tonal is Transient, and vice versa.
The word “considered” here is important: the controls in the Split section
simply affect which areas of the sound across time and frequency are
considered Transient or Tonal, and do not alter the sound on their own.
SplitEQ provides four controls for shaping the operation of the Structural
Split: the Source and Transient Separation controls determine how the Split
identifies regions, and the Transient Decay and Smooth controls allow you to
shape the transitions between Transient and Tonal regions.
Additionally, there is a master solo button on the right end of the Split
controls which is provided to facilitate tuning since it is often helpful to
listen to the Transient and Tonal signals in isolation to hear the effects of
these controls.
Source
This menu box includes “coarse” algorithmic tunings for different audio
sources as suggestions for the separation engine. In general, you will see the
best results by matching the Source to the input audio.
These coarse Source Type tunings essentially scale the internal algorithm
parameters used by the Transient Separation control to split the input audio.
Tunings for higher polyphony or complexity (full drums, electronic beat,
piano, guitar, vocal) tend to split best on source material that has higher
polyphony or complexity.
That said, you may find interesting results with tunings that do not match the
source.
Source| This menu box includes “coarse” algorithmic tunings for different
audio sources as suggestions for the separation engine. In general, you will
see the best results by matching the Source to the input audio.
These coarse Source Type tunings essentially scale the internal algorithm
parameters used by the Transient Separation control to split the input audio.
Tunings for higher polyphony or complexity (full drums, electronic beat,
piano, guitar, vocal) tend to split best on source material that has higher
polyphony or complexity. That said, you may find interesting results with
tunings that do not match the source.
---|---
Source Lock| Locks the Source control as you change presets.
Transient
Separation
0-100%| Affects the isolation level for transients across the spectrum.
This control sets the main transition region or decision point where audio
splits (in time and frequency) into separate Transient and Tonal streams. At
higher values, Transient regions will be smaller and have sharper boundaries
in terms of time and frequency.
This is the main control you will use to fine-tune the Split. If you solo the
Transient signal and increase Transient Separation, less of the sound will be
classified as Transient.
Transient Decay
0-100%| Increases the release time of Transient regions, resulting in longer
Transient areas and slower Tonal swells.
This control limits how quickly a region is allowed to transition (in time and
frequency) from Transient to Tonal, thus increasing the decay on the
Transient regions. Larger values of Transient Decay will limit the transition
rate substantially. This control could equally be named “Tonal Swell”, as
larger values will also increase the auto-swell period in the Tonal Channel.
Smoothing
0-50 ms| This control essentially controls the speed of the decision-making
process, preventing it from making too fast a decision either way. This is
useful for trimming out unwanted transient chirps or smoothing rough
transitions. It can also be musically useful for slowing the attack of
Transient regions. In general, turning this control up will reduce the
differences between the EQ curves.
Tuning the Split
You can certainly get good results out of SplitEQ without ever changing any of
the Split section controls, but learning how to use them will allow you to
more precisely target particular aspects of a sound. The following steps may
be helpful in tuning the Split.
-
Choose an appropriate source in the Source popup for your program material.
-
Use the solo button to audition the Transient or Tonal signals in isolation. It is significantly easier to hear what the controls are doing with the solo engaged.
The following settings can be useful for observing how the Split is working.
• Transient Solo Active
• EQ Bypass Active
• Analyzer – Source: All, Routing: Pre + Post, Decay: Very Fast
With these settings, the green curve represents the transient portion. The visible portion of the gray curve above the green portion effectively represents the portion of the signal which is tonal. -
If necessary, adjust Transient Separation, Transient Decay, and Smoothing until you reach your desired results. The streams do not necessarily have to be completely distinct from each other.
After making some adjustments to the EQ curves in the plugin, you may find small adjustments in the Split settings useful for making global adjustments to the application of your EQ curves.
The Transient and Tonal audio streams automatically mix back together at
SplitEQ’s output to perfectly reconstruct the input signal.
You will not hear any change in audio as you adjust the controls in the Split
section unless the Transient and Tonal EQ curves are different or you are
soloing Transient or Tonal.
A Note About Latency
In order to effectively separate the incoming audio signal into Transient and
Tonal audio streams, the Structural Split™ keeps a small running history of
the audio signal.
This introduces a significant bit of latency, which is expected.
Most modern DAWs will compensate for such latency, so SplitEQ will not audibly
delay the audio signal in your sessions. However, due to this inherent
latency, SplitEQ is not fit for real-time use.
| Sample Rate (Hz) | Latency (Samples) |
|---|---|
| 44,100 | 3,592 |
| 48,000 | 3,592 |
| 88,200 | 7,176 |
| 96,000 | 7,176 |
| 176,400 | 14,344 |
| 192,000 | 14,344 |
Master
The Master section contains controls and metering for the post-EQ Transient
and Tonal signals as well as the spectrum analyzer.
The bar meters display the peak and RMS amplitude for the Transient and Tonal
signals, with the lighter-colored bar representing the RMS, and the darker-
colored bar representing the peak. Infinite-hold clip indicators appear above
the meters. Click on the clip indicators to clear them.
| Solo | Solos the Transient or Tonal audio stream (post-EQ). |
|---|---|
| Output Gain | Amount of gain in dB (-30 to +30) to apply to the audio post. |
These values can be moved together or separately. Linked adjustments preserve
any offset between Transient and Tonal Gain.
Phase Invert| Inverts the phase of the plugin’s output.
Pan
(Mono/Stereo or
Stereo only)| Adjusts the L/R balance of the entire Transient or Tonal audio
stream. These values can be moved together or separately.
Linked adjustments preserve any offset between Transient and Tonal Pan.
M/S (Mid/Side)
(Stereo only)| Adjusts the stereo width of the entire Transient or Tonal audio
stream. These values can be moved together or separately.
Linked adjustments preserve any offset between Transient and Tonal Pan. To
switch from Pan to M/S mode, click the Pan label and select “M/S”.
Scale| Scales the overall EQ curve for the Transient or Tonal audio stream.
These values can be moved together or separately.
Linked adjustments preserve any offset between the Transient and Tonal Scale.
Global Bypass| Bypasses the plugin completely.
EQ Bypass| Bypasses the EQ section, but includes any alterations made in the
Master section.
Spectrum Analyzer
The Spectrum Analyzer displays the spectrum of one or more signals on the
plot. SplitEQ’s analyzer is especially useful because it can display the
spectrum of the Transient and Tonal signals as well as the plugin’s input and
output.
The controls for the Spectrum Analyzer are located in the bottom right corner
of the plugin. The first button turns the analyzer on and off. The second
button pops up a panel with additional settings for the analyzer. Finally, the
Pre and Post buttons adjust the routing of the analyzer.
Analyzer Settings
Source| The spectrum analyzer has four source options:
• All – the summed Transient and Tonal signals.
• Split – separate views of Transient and Tonal signals. (pre or post)
• Transient – only the Transient signal.
• Tonal – only the Tonal signal.
---|---
Routing| Select pre and/or post-EQ routing for the spectrum analyzer.
When Source is set to Split, the analyzer can be either pre or post, but not
both.
Resolution| Adjusts the resolution of the analysis.
“Best for Frequency” and “Better for Frequency” will capture more detail about
the frequency, but with less frequent updates.
“Better for Time” and “Best for Time” will show less frequency detail but
update more often.
Decay| Sets the decay rate for the peaks of the analyzer.
Freeze| Enables infinite peak hold on the plot. When active, existing peaks
will not decay, and new peak values will be held, allowing you to see the
peak amplitude at any given frequency.
Preset Bar
Located at the top of the SplitEQ plug-in, the Preset Bar lets you load and
save presets, along with several other features.
When SplitEQ is installed, a library of settings is placed into the
Controls (from left to right)
Undo| The Undo button undoes the last chance and restores the plugin to the
previous state. Pressing this button multiple times will move you backward in
the plugin’s state history.
---|---
Redo| The Redo button reverses the last undo command if any. Pressing this
button multiple times will move you forwards in the plugin’s state history.
Previous Preset| Loads the preset before the current preset in the preset
menu.
Next Preset| Loads the preset after the current preset in the preset menu.
Preset Chooser| Choose a preset from the Factory or User preset collections.
• Save as… Save the preset with a new name or location.
• Load… Open a preset from a location on disk.
• Import… Copy a preset from a location on disk into the
User preset collection.
Save| Saves the preset to disk.
A I B| Switches between two temporary plugin states, A and B. This is useful
for making A/B comparisons.
• Click A or B to switch states.
• Click I to copy state A into B.
• Click J to copy state B into A.
The A and B states are not saved in your DAW session. When you load a session,
the current settings for the plugin will be loaded into A and B.
Info (i)| Opens a drop-down menu with various help topics and settings.
• User Guide – Open this document.
• Tutorial – Open the tutorial which was displayed the first time the plugin
was loaded.
• Webpage – Launches the SplitEQ webpage.
• Theme – Select a color theme for the whole UI.
• Use OpenGL – Enable or disable OpenGL for the analyzer.
After changing this value, you must close and re-open the plugin window for
the change to take effect.
(N.B. OpenGL is unavailable on certain systems lacking sufficient support. If
this is the case, this setting will be hidden.)
• Tooltips – Enable or disable tooltips.
• Invert Handle Tabs – Invert the direction of the Transient and Tonal band
handle tabs.
Zoom| Clicking the magnifying glass button will automatically zoom the plot to
fit its contents. Click the drop-down menu to the right of the button to
choose a zoom setting from a list.
Conclusion
We hope you enjoy the SplitEQ plug-in and put it to good use in all of your
mixes.
Please be sure to check out Eventide’s other native plug-in offerings for more
unique and interesting effects.