Filter sweeps: lo, hi, & anywhere in between

Aloha, Lohi.

Whether you’re a music producer, DJ, sound designer, or mix engineer, you probably have a need for a simple filter that doesn’t get upset when you automate it or change it in realtime.

Although many filtering plugins exist, we’ve always struggled to find one that was easy to use and did what we wanted: sweepable frequency, variable slope, & independently controlled resonance. So we built those things into Lohi, and we included a killer analog-modeled limiter/saturator for some character and a mix knob for the filter section. Automate any parameter you like: filter type, saturation, mix — they’re all meant to be happily controlled without artifacts, clicks, or pops.

Interface Preview

Here’s a screenshot of Lohi in action. Click anywhere on the interface to jump to a control’s definition below.


Primary Controls


Filter Type

Changes the analog filter type.

Option About

Passes low frequencies while attenuating high frequencies


Passes high frequencies while attenuating low frequencies


Passes frequencies within a certain range or band


Filter is disabled

  • Default LO

Filter Freq

Precisely controls the center frequency of the filter.

  • Min 20Hz
  • Max 20.0kHz
  • Default 2.00kHz

Filter Slope

Continuously varies the steepness of the filter in dB per octave.

  • Min 6.0dB/Oct
  • Max 96.0dB/Oct
  • Default 18.0dB/Oct

Filter Resonance

Controls the amount of resonance at the Filter Freq.

Lohi is an analog filter design that uses feedback. When that feedback loop gets large enough, some resonance or ringing will occur. We recommend using the Lim/Sat controls to prevent any digital overs that might occur when the resonance is turned up.

  • Min 0.0dB
  • Max 18.0dB
  • Default 6.0dB

Filter Mix

Controls the overall impact of the filter. At 0%, the filter has no effect.

This mix control won’t introduce comb filtering or other unexpected blending artifacts like a standard parallel mix. Instead, it’s designed to gracefully go from unfiltered to completely filtered.

  • Min 0%
  • Max 100%
  • Default 100%


Lohi’s Lim/Sat section is a multi-stage analog-modeled saturator/limiter. It’s not very much like a typical digital maximizer or soft clipper: it can pump a lot further and has a smooth, big-iron transformer sound.

Lim/Sat On/Off

Enables the limiter/saturator section.

Options: Off, On

  • Default On

Lim/Sat Threshold

Controls the point at which limiting and more pronounced satuation will occur. Lower thresholds yield more limiting & saturation.

  • Min -36.0dB
  • Max 0.0dB
  • Default 0.0dB

Lim/Sat Color

Controls the overall amount of analog coloration, saturation, and harmonic distortion.

At 0%, the Lim/Sat is rather clean sounding. 100% is a nice analog middle-ground, and 200% gets pretty rich and saturated.

The amount of analog color is greatly influenced by the Lim/Sat Threshold.

  • Min 0%
  • Max 200%
  • Default 100%


Output Gain

Varies the output gain, after the Lim/Sat processing.

Output Gain includes a level meter embedded in the slider. This meter shows the peak level of the signal both pre (lighter color) and post (darker color) Lohi’s processing.

  • Min -24.0dB
  • Max 12.0dB
  • Default 0.0dB

Master Mix

Controls the overall Lohi mix. Smoothly transitions from no effect to fully filtered.

  • Min 0%
  • Max 100%
  • Default 100%

Master On/Off

Bypasses Lohi’s processing.

Options: Off, On

We recommend using the Master On/Off instead of your DAW’s plugin bypass to avoid digital artifacts.

  • Default On

Advanced Controls

The Advanced section offers more precise control and fine adjustment options.

To access Lohi’s advanced controls, click the ••• icon in the sidebar.

Lim/Sat Auto Gain

Sets the reference peak level used by the limiter’s auto gain algorithm.

Lohi’s automatic gain compensation attempts to automatically make up for the gain lost during limiting so that the output volume remains approximately constant for different Lim/Sat Threshold settings.

It works best when the Lim/Sat Auto Gain setting matches the peak level hitting the limiter. For example, if your input signal consistently peaks at -6.0dB, set Lim/Sat Auto Gain to -6.0dB.

The maximum gain compensation is applied when Lim/Sat Auto Gain is set to 0.0 dB. At -20.0dB, Lim/Sat Auto Gain is turned off completely.

The automatic gain compensation in Lohi is not based on the input signal. Instead, a combination of the settings of the Lim/Sat Threshold and Lim/Sat Auto Gain determine the amount of gain compensation.

  • Min -20.0dB
  • Max 0.0dB
  • Default 0.0dB

Filter Glide Time

Controls approximately how long it takes the Filter controls to travel from one extreme to the other.

Clicks and pops may result at extremely fast filter glide times (like 10ms).

  • Min 10ms
  • Max 2.500s
  • Default 250ms

HQ Mode

HQ Mode is our no-holds-barred processing mode where super high quality audio is given priority over CPU usage.

When HQ Mode is turned On, Lohi uses a higher precision algorithm, providing better spectral resolution at the expense of some added latency (~50 ms) and higher CPU usage.

Options: Off, On

We recommend using HQ Mode when you need the highest possible quality and don’t mind 2-4x higher CPU usage. An important lead instrument, vocal, or a mastering session is a great place for HQ Mode.

HQ Mode will require more CPU resources and result in a slightly higher processing delay (latency). To ensure proper delay compensation in your host/DAW, automating HQ Mode is not recommended.

  • Default Off


Supported Channel Configurations

Input Channel # Output Channel #
1 1
1 2
2 2


Annlie Huang / Chris Conover / Diana Zheng / Jack Stratton / Peter Raymond / Rob Bisel / TaeHo Park / Tyler Duncan


Devin Kerr / Rob Stenson / Jasper Duba / Noah Dayan


TaeHo Park / Tiago Frúgoli / Gustavo Guzmán / Reda Kermach / Noah Dayan / Gal Cohen / Sydney Bolton

About Goodhertz Plugins

User Interface

Goodhertz plugins are made to be workhorse tools that sound amazing. We’ve put a lot of thought and care into the audio quality and plugin usability, and for that reason, we’ve opted for simple and direct controls & interfaces that don’t rely on photorealistic knobs or ornamental screw heads to communicate their meaning.

We’ve also decided to only include meters and graphs when we feel they will directly lead to a better sonic result. Meters/graphs can consume significant CPU resources, and we firmly believe that if it sounds good, it is good.

Our meters can be manually enabled or disabled via the “Enable Metering” User Preference.

Keyboard Shortcuts

Action Keyboard Shortcut
Enter New Parameter Value Once you’ve tapped or double-tapped a control, type in a value, then hit Enter, Return, or Tab
Increment Parameter Value or arrow keys
Decrement Parameter Value or arrow keys
Jump to Next Parameter Tab
Jump to Previous Parameter Shift + Tab or ` (backtick)
Escape Parameter Focus / Close any Open Drawers Esc
Tap Tempo t (N.B. For this to work, you must have a BPM control selected.)

Right-Click Actions

Action Instruction
Read about Control in Manual Right-Click & select “Read About [control]”
Reset Control to Default Right-Click & select “Reset [control] to Factory Default Value”
Lock a Control when switching presets Right-Click & select “Lock [control] When Switching Presets”
Copy all current plugin settings Right-Click & select “Copy All Settings as URL to Clipboard”
Paste all plugin settings Right-Click & select “Paste All Settings From Clipboard”
Reset all plugin settings to default Right-Click & select “Reset All Settings to Factory Default”
Reset all plugin settings to Preset Right-Click & select “Reset All Settings to [preset] Preset”
Save Preset with current plugin settings Right-Click & select “Save Settings as New Preset”
Update Preset with current plugin settings Right-Click & select “Update [preset] Preset With Settings”
Go to the plugin’s product page Right-Click & select “Goodhertz [plugin name]”

Right-Click Preferences

Action Explanation
Language Switch the display language of text elements in Goodhertz plugins. We currently support the following languages: English, Spanish, Portuguese, French, Japanese, Korean, Chinese (Simplified), Chinese (Traditional), and Arabic.
Always Open Advanced Pane By default, this is Off — i.e. when the plugins open, they do not show you the advanced controls available by hitting the ••• button in the sidebar. If you’d like to always see the advanced controls, enable this preference.
Dark Mode Allows you to choose the color palette used for displaying the interface. If you prefer the look of dark colors (or work in a darker environment) enable this option. The Auto option will automatically adjust the color scheme depending on the system preferences of your machine (Mac only).
Enable Metering By default, this is On — i.e. in normal operation, all audio meters and visualizations available in Goodhertz plugins are enabled and running. If you’d like to turn them off and disable all metering and visualization, deselect this option. And to turn them back on, simply reselect it. N.B. If you’re struggling to use a large number of Goodhertz plugins on an older processor with an integrated GPU, sometimes disabling metering can help.
Enable Scroll Input By default, all Goodhertz sliders can be scrolled in addition to dragged. If you find this behavior unnecessary, deselect this option and no scrolling events will be used to control Goodhertz sliders.
Enable Tooltips By default, this is On — i.e. all controls will show a tooltip on hover. If you find this behavior unnecessary, deselect this option and no tooltips will be shown.
Require Double-Click for Keyboard Focus By default, you can get keyboard focus on any Goodhertz control with a single click. Enable this option to ensure keyboard focus only occurs on double clicks.
Window Size Enlarge or shrink the Goodhertz plugin window by selecting an option here. This will save your preference for all instances of this plugin.

Mouse Modifiers

Action Combination (Mac) Combination (Windows)
Reset Parameter to Default Value Option + Click Alt + Click
Move Control with Coarse Precision Shift + Drag Shift + Drag
Move Control with Fine Precision Command + Drag Ctrl + Drag
Move Control with Normal Precision Drag Drag


Unintentional digital clicks and pops are the worst. They happen for lots of reasons and often end up wasting your time with needless revisions or mastering surgery. When they go unnoticed, they can make their way onto commercial albums and releases.

Plugin automation is a common cause of clicks and pops. Sweeping an EQ band, changing a delay setting, and even automating a plugin bypass can cause digital artifacts if poorly handled.

This is not true for Goodhertz plugins. Any parameter in a Goodhertz plugin, even on/off switches, can be automated freely and smoothly without clicks, pops, or zipper noises (unless otherwise noted). You can push them, pull them, LFO them — whatever you do, they’ll handle it gracefully.

Since our Master On/Off controls won’t create artifacts, we recommend that you use them rather than your DAW-supplied plugin bypass if you want to disable plugin processing.

Plugin Settings

Goodhertz plugin settings can be copied and pasted as text urls, which look like this: https://goodhertz.com/vulf-comp/3.0.9?cm=0&wf=0&lf=100&lfc=50

To copy and paste, right click anywhere on the plugin interface and select either the copy or the paste option.

E.g. If you paste “https://goodhertz.com/vulf-comp/3.0.9?cm=0&wf=0&lf=100&lfc=50” into Vulf Compressor it will recall the settings associated with that url. This way you can easily send an exact plugin setting to someone — in an email or even a tweet — without any guesswork or screenshots.”

System Requirements

Mac OS X ≥ 10.12

Audio Unit 64-Bit, VST 64-Bit, VST3 64-Bit, or AAX 64-Bit host

Windows ≥ 8

VST 64-Bit, VST3 64-Bit, or AAX 64-Bit host

Contact Support

To send plugin feedback, please e-mail us at feedback@goodhertz.com.

If you have a quick question, send us a tweet @Goodhertz. We’re often able to respond faster to tweets than emails.

If you’re having trouble, experiencing a technical issue, or you think you’ve found a bug, please email support@goodhertz.com.

Find all our contact info & bug-reporting protocol on the contact page.