Sordina User Guide
A mute is a device a musician can fit to their instrument to change its sound. There is usually a reduction in volume and a change in tone depending on the instrument, the type of mute, and the performer.
A mute works like an acoustic equalizer. By blocking sounds and absorbing energy the mute filters out certain frequencies while allowing others to pass.
Introduction
Sordina is a VST effect plugin that runs on GNU/Linux, Windows, and Mac OS. It’s purpose is to emulate a wide variety of instrument mutes – currently brass and saxophone.
As with real mutes each of Sordina’s virtual mutes has a different character and responds slightly differently to the input signal they are applied to.
Here’s an A/B comparison of a trombone playing with a real bucket mute and the original un-muted recording being processed by Sordina’s virtual bucket mute.
Installation
Please see the detailed installation guide for instructions on how to setup Sordina on your system.
Quick start

As the plugin is intended to alter the sound of an audio signal it should be placed either after a VST instrument in the plugin chain, on a track containing audio, on an audio bus, or on the master output.
Sordina can be added to a DAW track as either an insert or send effect. This guide will assume it’s being used as an insert.
After the plugin has been added to the audio chain select a mute from the preset browser.
Interface

Quick Tips
If you hold the shift key on your keyboard while clicking on a knob you’ll be able to type in a specific value.
You can move the knobs on the interface more precisely by holding down the control key on your keyboard at the same time.
Double clicking a knob will reset it to its default value.
Clicking the Libre Wave logo will display some information about the plugin and provide a clickable link to the librewave.com website.
Mix & Gain
The Mix knob allows you to adjust the balance between the incoming dry signal and the processed wet signal. To recreate the true sound of the mute on a solo instrument this should be set to 100%. Values lower than this are useful for blending the sound with other instruments and for creative purposes.
The presets that come with Sordina have been volume calibrated against reference recordings but this calibration may not necessarily fit with the audio you will feed into the plugin. The gain knob allows you to adjust the output volume to suit your specific needs.
Frequency analyser & Meters

The window in the middle of the interface displays a real time frequency analysis of the incoming and outgoing audio. The yellow colour shows the unprocessed input signal, while the muted signal is displayed as blue.
On each side of this window is a traditional volume meter. The yellow one on the left shows the volume of the incoming audio while the blue meter on the right shows the volume of the processed output signal.
Filter

The knobs marked HPF and LPF control the cut-off frequency of a high-pass and low-pass filter respectively.
Like a real mute the response of the virtual mutes varies depending on the specific instrument being played. The filter is useful to alter the characteristics of the muted sound to adjust for such variations or to sculpt the output audio for a desired result.
A graphical representation of the filter is overlaid on the FFT analyser.
Wah Wah
When a compatible mute is selected the Wah knob will be enabled. This knob can be controlled in real time using host automation to create a live wah wah effect.
Automation
All of the knobs will respond to automation messages from your DAW. Check your DAW’s user guide for details on how to access automatable parameters.
You can load mutes on the fly by automating the Presets parameter. You should avoid doing this while audio is playing on the track where the plugin is inserted because it will result in unwanted clicks or pops. If you want to change the mute in the middle of a line you should leave enough silence in the part to avoid this issue.
Preset Browser
The browser is divided into three columns. In the left column you can select the instrument you want to mute. For example if you are routing a trumpet recording or a trumpet virtual instrument into Sordina then you’ll probably want to select Trumpet & Cornet from this column. However there are many creative combinations possible by selecting a mute intended for a different instrument.
From the centre column you can select the type of mute. The options available will vary depending on the instrument. See the tables below for more details.
The third column displays the mutes available for the selected instrument and mute type. All of the virtual mutes in Sordina have been created by analysing recordings of real instruments and their mutes*. The names you see in the third column contain the brand of mute that was analysed and either the mute’s model or some other relevant information
Clicking the star icon next to a mute name will add it to your favourites list, clicking it again will remove it. You can see all of the mutes you have marked as a favourite by clicking the larger star icon next to the search box above the first column of the preset browser.

You can filter the list of mutes by typing in the search bar and hitting enter.
If you’d like to save any changes you’ve made to a preset you can do so by clicking the Save Preset button next to the search bar.
Mutes
French Horn
Cup | Humes & Berg Stonelined | ||
Practice | Humes & Berg Sh Sh | ||
Stop | Humes & Berg Stonelined | ||
Straight | Humes & Berg Philharmonic | Humes & Berg Stonelined | The Warburton Tunable |
Piccolo Trumpet
Cup | Tom Crown Aluminium | ||
Harmon | Tom Crown: Stem In/Out | ||
Misc | Felt | ||
Practice | Jo Ral Aluminium | Tom Crown Aluminium | |
Straight | Denis Wick Aluminium | Jo Ral Brass Bottom | Wallace Aluminium |
Trumpet & Cornet
Bucket | Humes & Berg Stonelined | Jo Ral Brass Bottom | ||||||
Cup | Denis Wick Adjustable 1 | Denis Wick Adjustable 2 | Humes & Berg Cup 1 | Humes & Berg Cup 2 | Jo Ral TriTone | |||
Harmon | Denis Wick: Stem In/Out | Humes & Berg: Stem In/Out | Jo Ral Bubble: Stem In/Out | Tom Crown: Stem In/Out | ||||
Misc | Felt | Humes & Berg Pixie | Plunger 1 | Plunger 2 | Plunger 3 | |||
Practice | Bremner Sshh | Denis Wick Aluminium | Humes & Berg Mel-O-Wah | Mute Tube | ||||
Straight | Denis Wick Aluminium | Denis Wick Pianissimo | Jo Ral Brass Bottom | Jo Ral Plastic | Leblanc Aluminium | Pro Tec Fiber | Tom Crown Aluminium | Alessi Vacchiano |
Flugelhorn
Bucket | Humes & Berg Velvet Tone | ||
Cup | Humes & Berg Stonelined | ||
Practice | Humes & Berg Aluminium | Humes & Berg Sh Sh | Humes & Berg Stonelined |
Straight | Humes & Berg Aluminium | Humes & Berg Stonelined |
Trombone
Bucket | Humes & Berg Bucket | Humes & Berg Velvet Tone | Jo Ral Aluminium | ||||
Cup | Humes & Berg Mic-A-Mute | Humes & Berg Cup 1 | Humes & Berg Cup 2 | Jo Ral Aluminium | Denis Wick Cup | ||
Harmon | Humes & Berg Wa-Wah: Stem In/Out | Jo Ral Bubble: Stem In/Out | |||||
Misc | Buzz | Humes & Berg Cleartone | Humes & Berg Derby Hat | Humes & Berg Pixie | Plunger 1 | Plunger 2 | Solotone |
Practice | Humes & Berg Sh Sh | Liberty Practice | |||||
Straight | Humes & Berg Stonelined | Jo Ral Brass Bottom | Soulo | Alessi Vacchiano | Tom Crown Straight |
Bass Trombone
Bucket | Humes & Berg Velvet Tone | Jo Ral Aluminium | |
Cup | Denis Wick Aluminium | Humes & Berg Mic-A-Mute | Jo Ral Aluminium |
Harmon | Humes & Berg Wa-Wah | Jo Ral Bubble: Stem In/Out | |
Misc | Plunger | ||
Practice | Humes & Berg Sh Sh | ||
Straight | Denis Wick Aluminium | Humes & Berg Stonelined | Jo Ral Brass Bottom |
Euphonium
Practice | Denis Wick Aluminium | |
Straight | Humes & Berg Stonelined | Jo Ral Aluminium |
Tuba
Practice | Schlipf | Voigt |
Straight | Humes & Berg Stonelined | Jo Ral Aluminium |
Saxophone
Practice | E-Sax Whisper | MMD | Sax Mute One |
*Libre Wave and Sordina are in no way affiliated or endorsed by the manufacturers of the mutes analysed for the creation of this plugin. Their names and trademarks are referenced only as descriptors for the user’s information.
Acknowledgements
Produced by: David Healey
Demo Audio: David Budimir
GUI Design: David Healey
