Audio hardware & software

This book contains general information about hard- and software.

Hardware

Hardware

Types of Audio Cables

There's a difference between analog and digital audio cables:

In the Blackbox, you will find both of these types of cables, for most setups we use analog cables such as Jacks, XLR, Tulp, and sometimes Speakon. Digital cables are used more as 'interface cables' and common ones are USB and Network cables.

Audio-Cables-types.png

Analog Cables

Most analog cables are used to transmit 3 types of signals:

This 'boosting' of the signal can be accomplished using amplifier equipment such as mixers, audio interfaces, and DI (Direct-In) Boxes.

UNBALANCED cables have only 2 wires:

  1. Signal
  2. Ground

BALANCED cables have 3 wires:

  1. Signal (+)
  2. Signal (-)
  3. Ground

Balanced cables are generally better for noise cancellation, we're not going to deep dive into this for now, but the use of 2 Signal (+) and (-) makes that the interfering noise that occurs between sender and receiver is canceled out.

Jack Cables

Audio-Cables.png

A TRS cable consists of:

When working with Jack cables, you can choose between unbalanced and balanced cables. A lot of instruments such as guitars and keyboards have unbalanced connections. When building sound setups over longer distances, we always advise balanced (TRS) cables.

XLR Cables

Audio-Cables-XLR.png

XLR cables are always balanced and are also used commonly as microphone cables and also have 3 contact points. (Signal +, Signal -, Ground)

XLR connectors are much sturdier and the cables are generally better shielded than Jack connectors.

Tulp/Cinch cables
Tulp cables are not that common anymore to use, but they are mentioned in some of the patch setups in the submenu (<-). Tulp cables are also called RCA or 'phono' connectors and you can find them still used in audio hi-fi systems, turntables, DJ controllers, and some audio interfaces.
Example:
We can use two 2x RCA -> 2x Jack cables to connect 4 different outputs of the Focusrite Scarlett 2i4 Audio interface to 4 different speakers for a quadraphonic speaker setup. (SEE PAGE)
focusright-tulp-optie-2__.jpeg
Speakon

Speakon connectors and cables are used for connecting more power-hungry speaker equipment and amplifiers together. They are used for bigger systems and can be found in theaters and at festivals. Generally, you will only use these cables in bigger setups.

dap-speakon-speakon-3m-2x2.5mm-speakercable.jpg

Hardware

Using Audio Interfaces

Use an audio interface for recording sounds onto your computer, or to play sound from the computer back into the space.

Screenshot 2022-10-05 at 14.38.55.png

Example with the Focusrite Scarlett 2i4
For recording some simple sounds you can use the Focusrite Scarlett 2i4 that is available in most Blackboxes and uitleen, or any other similar audio interface. For now we stay to the Scarlett 2i4, since it's been used the most in the workspace. An audio interface lets us interact with sound in different ways, you can use the interface for example to:
  • Connect instruments and/or microphones to a Speaker setup (no computer)
  • Connect instruments and microphones to the computer via USB for recording
  • Play sounds from your computer via USB to speakers using the audio interface
Different audio interfaces vary in number of inputs and/or outputs. Also some might include software for recording your sounds with, this is called a DAW (Digital Audio Workstation). Some popular DAW's are AbetlonLive, Reaper or StudioOne.
Depending on the audio interface, you will need to install additional Drivers (group of files that enable hardware devices to communicate with the computer). You can check if your operating system needs a driver by going to the website of the interface's manufacturer. In this case for the Focusrite Scarlett 2i4, no additional drivers are needed on Mac.
Screenshot 2022-10-05 at 14.48.49.png
Connecting everything!
  • Connect the Scarlett 2i4 to your Mac using the included USB cable
  • In system preferences on your laptop/pc select "Scarlett 2i4" as the input and output device
  • You can also select the "Scarlett 2i4" from your preferred Audio Software DAW (Digital Audio Workstation) such as AbeltonLive, StudioOne, Reaper.
Hardware

Basic Stereo Speaker Setup

Making a stereo speaker setup using 2 speakers, audio interface, pc
Generic Stereo Speaker Setup
To make a basic stereo setup with your computer you need the following items:
  • An audio interface
  • A USB cable (USB cable type depends on your computer and audio interface)
  • A pair of audio cables for each channel (Depending on the output type the audio interface you need the following connectors: RCA - mono Jack / mono Jack - mono Jack / mono mono Jack - XLR)
  • A pair of active speakers

Schermafbeelding 2022-05-09 om 13.36.56.png

Hardware

Quadrophonic Speaker Setup

Making a quadrophonic speaker setup using 4 speakers, audio interface, pc

Hardware

Zoom recorder

Quick guide: https://zoomcorp.com/media/documents/E_H4n_Pro_QuickGuide.pdf

Software

Software

Reaper

Reaper is a cost-effective and highly customizable digital audio workstation (DAW) used by musicians, audio professionals and artists. Its key benefits include:

1. Affordability: Professional-grade features at a budget-friendly price.
2. Customizability: Tailor the software to your workflow with customizable shortcuts and themes.
3. Efficiency: Runs smoothly on a wide range of computer setups.
4. Multitrack Recording: Excellent for multitrack recording and editing.
5. Plugin Compatibility: Seamlessly integrates with third-party VST and AU plugins.
6. Cross-Platform: Available for both Windows and macOS.
7. Active Community: Access to a vibrant user community and support forums

A 60 day trail is available at https://www.reaper.fm/ or you can buy discounted license.
(although reaper is worth the license, users have reported the evaluation period to be infinite, so... just try..) 

Learn 

click image to go to website

Screenshot 2023-10-05 at 16.40.11.jpeg


Screenshot 2023-10-05 at 18.08.44.jpeg

free signup voor an e-book on podcast editing in reaper

 

Software

Ableton Live

Ableton Live is a popular digital audio workstation (DAW) known for its real-time performance capabilities, intuitive interface, extensive sound library, and Max for Live integration. Its benefits include:

A 30 day trail is available at https://www.ableton.com/en/trial/ or you can buy it with a student or education discount.
Licensed Abelton live is installed & available on most Blackbox workstations for HKU students.

Add this to send OSC from Ableton to any other software https://www.showsync.com/tools#livegrabber 

Learn 

click image to go to website

live tut.jpeg


Screenshot 2023-10-05 at 16.33.01.jpeg

Software

Audacity


Audacity is an easy-to-use, multi-track audio editor and recorder for Windows, macOS, GNU/Linux and other operating systems. Audacity is free, open source software.

download: https://www.audacityteam.org/download/ 

getting started: 


more help: https://support.audacityteam.org/ 

Beware! Using Audacity to edit your source files is DESTRUCTIVE meaning any adjustments made to your file are permanent. Therefor, good practise is to work in a copy of your original file.

Software

Adobe Audition

Audition is a comprehensive toolset that includes multitrack, waveform, and spectral display for creating, mixing, editing, and restoring audio content. This powerful audio workstation is designed to accelerate video production workflows and audio finishing — and deliver a polished mix with pristine sound.
Part of the Adobe Creative Cloud. Works seamlessly with Adobe Premiere a.o.

Learn the basics on the adobe website 
or watch this to do your first audio recording & edit

Less useful for  creating music but awesome for video & podcast:
for example: 
- Easily remix music to fit your video
- repairing your recorded audio 

Multichannel audio

In this chapter you can find tools, tutorials, system settings and tips & tricks on how to create multichannel audio set-ups

Multichannel audio

Multichannel audio in Isadora and Reaper

With Isadora you have control over your interactive performance with audio over 2 channels or more. You can work with this Isadora example file and audio files:

https://nextcloud.hku.nl/s/Bs5qoDqGHsLXdGo

here is a usefull tutorial about working with multichannel audio in Isadora: https://support.troikatronix.com/support/solutions/articles/13000084953-tutorial-getting-started-with-multi-channel-audio-in-isadora-3-0-8

Since 2024 Focusrite control software doesn't support 1st and 2nd Gen Scarlett Solo, 2i2 and 2i4. But we work with them on HKU. Use this page to configre the setup anyway. 

In Reaper (audo software or DAW) you can prepare your audio file with multiple channels if you want to use your audio file in a conventional way by playing linear from start to finish or looping it. This should also be possible in other DAW's. Each channel can send your audio to a different speaker depending on your setup you can work with a 2, 4, 8 etc speakers.

Make a mutichannel audio file in reaper:


If you dont have a multichannel setup at hand READ this first! 

Mac only!

Download and install BlackHole audio plugin https://existential.audio/blackhole/download/?code=1579271348

You need this to create virtual outputs so you can create multichannel audio files in Reaper (or any other audio edit software) without having an actual multichannel setup at hand.

Restart your computer Open your audio edit software (Reaper) Go to preferences and go to Audio > Device, choose BlackHole 64ch in your Audio Device settings

This is created by Simone, for questions: simone.vandordrecht@hku.nl

Multichannel audio

4 speaker setup with Reaper

In this example we work with Reaper, Focusrite interface, 4 speakers, windows desktop.

The idea is to place the speakers in a square position so you can hear the audio coming from different directions. 

Software to be installed:
Reaper we work with Reaper because its free and relatively easy to setup, but there is more software to use for 4 channel setups (like Ableton or Isadora), depending on your needs
Focusrite control software (make sure you choose for the right device, Focusrite interfaces come in different types and versions which all have own control software environment) Since 2024 This software only works with version 4 hardware. 

Work with mono files

In most conventional audio setups we use 2 channels (left and right) and the audio source file is stereo (2 channels). Since we use a 4 speaker setup, we use 4 audio tracks in Reaper. Thus we have to use a mono (1 channel) audio file. Each mono file will be placed in one of the 4 single channels of reaper. If your source file is stereo you need to convert your files to mono first.
With Reaper follow this short tutorial https://www.youtube.com/watch?v=jLr0FPxd3K0&t=20s
Save the file:

save mono file reaper.png

Connect Focusrite interface

Open Focusrite control software
In the Output Routing tab Change stereo Monitor en Line outputs to mono by clicking [stereo]

To be able to hear anything through channel 1 & 2 you need to TURN UP THE MAIN VOLUME on the interface, or else you only hear channel 3 & 4 ;)

Screenshot 2024-08-29 at 15.29.52.png >>>>>>>>>>>>>>>>>>>>Screenshot 2024-08-29 at 15.31.13.png

Create your Reaper multichannel audio file

In Menu > Reaper > settings you should be able to locate Audio Device > Scarlet (your Focusrite interface), choose Apply & OK

Use command T(mac) or control T(windows) to make 4 tracks. Place your mono audio files on your tracks

View > Routing Matrix & Mixer

In the Routing Matrix change your settings so it looks like this:


Screenshot 2024-08-29 at 15.45.30.png

Now you should be able to play your audio through the 4 channels. 

In the Focusrite control software you can adjust the level of volume of the different channels. change 3 & 4 so it matches 1 & 2. 

Next step might be to automate the volume levels of the audiotrack from other software with MIDI or OSC... depending on the software you use in conjunction with Reaper. Any requests? Send an email to blackbox.ibb-pastoe@hku.nl & blackbox.oudenoord@hku.nl we'll get back to you on that!

If you dont have a multichannel setup at hand READ this: 

Mac only!

You need this to create virtual outputs so you can create multichannel audio files in Reaper (or any other audio edit software) without having an actual multichannel setup at hand.

Download and install BlackHole audio plugin https://existential.audio/blackhole/download/?code=1579271348

Restart your computer Open your audio edit software (Reaper) Go to preferences and go to Audio > Device, choose BlackHole 64ch in your Audio Device settings

This is created by Simone, for questions: simone.vandordrecht@hku.nl

Multichannel audio

Ambisonics and the ATK toolkit for Reaper for multichannel playback.

This page contains links to sources containing information about Ambisonics, the Ambisonics Toolkit, and several tutorials on how to use the plugins in conjunction with soft and hardware.

Ambisonics

Ambisonics is a full-sphere surround sound technique used for recording, mixing, and reproducing three-dimensional audio. Unlike traditional stereo or surround sound systems, which typically only cover a horizontal plane (like 5.1 or 7.1 setups), ambisonics captures sound from all directions: above, below, and around the listener.

Here’s how it works:

1. Sound Field Representation:
2. Recording Ambisonics:
3. Playback:
4. Applications:

In summary, ambisonics is an advanced sound format that enables full 3D audio immersion by capturing and reproducing sound from all directions, offering a much richer and spatially accurate audio experience compared to traditional surround sound methods.

 

Hardware setup

A typical ambisonics hardware setup includes:

  1. Ambisonic Microphone: A microphone with multiple capsules arranged in a tetrahedral or other pattern (e.g., Sennheiser AMBEO, Zoom H3-VR) to capture sound in all directions.

  2. Audio Interface: A multi-channel interface to record the signals from the microphone capsules, converting them into digital B-format signals.

  3. Computer with DAW: A digital audio workstation (DAW) with ambisonics plugins (e.g., IEM Plugin Suite, SPARTA) to process, encode, and decode the B-format audio for playback or mixing.

  4. Monitoring System: For playback, either a multi-speaker setup (for full 3D sound reproduction) or binaural headphones for VR/360 applications.

 

Speaker setup 

Here are a few common multi-speaker configurations used in ambisonics for 3D sound reproduction:

  1. Quadraphonic Setup (4 speakers): Four speakers are placed at the corners of a square or rectangle around the listener (two in front, two behind), offering a basic but immersive spatial sound experience, laying the groundwork for more complex surround systems.

  2. Cube Configuration (8 speakers): Speakers are placed at the corners of a cube, with four on the ground and four at elevated positions to cover all axes (left-right, front-back, up-down).

  3. Dodecahedron Configuration (12 speakers): Speakers arranged in a dodecahedron shape (12 equally spaced vertices) to capture more detailed directional sound.

  4. 3D Hemisphere (16+ speakers): Speakers are arranged in a half-sphere around the listener (above, in front, behind, and around) for immersive sound, often used in dome environments.

  5. Icosahedron Configuration (20 speakers): Evenly spaced speakers form a spherical shape for highly detailed spatial sound representation, often in higher-order ambisonics.

  6. Spherical Array (32+ speakers): A full 360° sphere of speakers, providing the most detailed and immersive sound experience for advanced higher-order ambisonics setups.

8 speaker setup configurations:

There are several different 8-speaker setups used for immersive audio experiences, especially in ambisonics, spatial audio, and surround sound configurations. Here are a few common types:

1. Cube Configuration (3D)
2. Octagonal Setup (2D)
3. 7.1 Surround Sound Configuration
4. Double Quadraphonic Setup (Vertical and Horizontal Planes)
5. Dual Layer Circle (Upper and Lower Rings)
6. Surround Sound with Height Speakers (5.1 + Height)
7. Horizontal Circle (Octagonal Layout)

 

Ambisonic toolkit

Via the following link you can find the download for the ATK toolkit for Reaper, and tutorials. There is a short explanation 

ATK separates the task of production work with Ambisonics into three distinct elements.

alt text
The Ambisonic Toolkit paradigmatic workflow.

 

 

Author
Capture or synthesise an Ambisonic soundfield.
Image
Spatially filter an Ambisonic soundfield.
Monitor
Playback or render an Ambisonic soundfield.

 

In its most simple form, Ambisonics can be regarded as splitting the panning law into two separate parts: encoding (Authoring) and decoding (Monitoring), where final panning (decoding) is deferred to an actual loudspeaker array at the time of audition. The ATK considers the Imaging (transforming) of a soundfield to be a critical step; this is where the artist shapes and processes the soundfield in a coherent way which isn’t easily available via the other models for working with spatial sound.

Many publicly distributed implementations of Ambisonics provide only encoding and decoding. While giving flexibility regarding final playback, failing to include transformers misses out the concept of imaging and fails to capitalise on the advantages of the sound-field sound-image paradigm intrinsic to Ambisonics.

What’s the difference?

The real power in working with Ambisonic over other multichannel surround sound techniques is that rather than being restricted to a sound-scene based paradigm (where the artist is presented with tools designed to build up a ‘sound scene’) Ambisonics supports a soundfield-kernel model. Here we construct a soundfield in the abstract, and can then shape it as desired. The result may be shaped into a ‘sound scene’, or perceived this way – but a soundfield-kernel approach gives much greater flexibility, and directly supports the realisation of more abstract outcomes. We regard this model as idiomatic for Ambisonics.

Along with powerful soundfield transforms – the spatial filtering tools enabling soundfield-kernel reshaping – the ATK provides a comprehensive set of Ambisonic encoders (including pseudo-inverse) and decoders (5.1binauralUHJ, full-3D) allowing users to thoroughly leverage the power of the Ambisonic technique.

Multichannel audio

Speaker configuration focusrite 1st and 2nd Gen Scarlett 2i4

Since 2024 Focusrite control software doesn't support 1st and 2nd Gen Scarlett Solo, 2i2 and 2i4. But we work with them on HKU.

To configure the 4 speakers setup go to your preferences in the audio software you work with. 

Windows settings:
Control Panel > Sound > Playback: Speakers (Focusrite USB Audio) > Configure > Quadraphonic

Example Isadora:

signal-2024-12-09-154159.jpeg

signal-2024-12-09-154159_002.jpeg

signal-2024-12-09-154159_003.jpeg

restart your Isadora file

Audio effects and plugins

Audio plugins, often referred to simply as 'plugins,' are software components used in digital audio workstations (DAWs) and other audio processing software

Audio effects and plugins

General

Audio plugins, often referred to simply as 'plugins,' are software components used in digital audio workstations (DAWs) and other audio processing software. These plugins serve various functions in the world of audio production and sound processing. Here are some of the primary functions of audio plugins:

1. Sound Processing and Effects: Audio plugins are commonly used to apply various effects and signal processing to audio tracks. They can modify the sound in real-time or during post-production. Common effects include equalization (EQ), reverb, delay, chorus, flanger, and more. These plugins allow users to shape and enhance the audio signal to achieve desired sonic characteristics.

2. Instrument Emulation: Virtual instrument plugins, also known as VSTi (Virtual Studio Technology Instrument) or AU (Audio Unit) instruments, replicate the sounds of real-world musical instruments such as synthesizers, pianos, guitars, and drums. Musicians and producers can use these plugins to create realistic instrument sounds without the need for physical instruments.

3. Dynamic Processing: Plugins like compressors, limiters, and gates are used for dynamic range control. Compressors, for example, can reduce the volume of loud sounds and boost the volume of quieter sounds, helping to even out the audio levels. Limiters prevent audio from exceeding a certain level, while gates can eliminate background noise during silent parts of audio recordings.

4. Pitch and Time Manipulation: Pitch correction plugins, such as Auto-Tune, can correct or modify the pitch of vocal recordings. Time-stretching and pitch-shifting plugins can alter the tempo and pitch of audio without changing its duration.

5. Noise Reduction and Restoration: Noise reduction plugins are used to remove unwanted background noise from audio recordings, enhancing the overall sound quality. Restoration plugins can repair damaged or degraded audio, such as old vinyl records or cassette tapes.

6. Creative Sound Design: Some plugins are designed for creative sound manipulation and experimental sound design. These may include granular synthesis, spectral processing, and convolution effects, enabling users to create unique and unconventional sounds.

7. Mixing and Mastering: Audio plugins play a crucial role in mixing and mastering music. They help balance the individual tracks in a mix, apply EQ and dynamics processing, add spatial effects like stereo widening, and prepare the final audio for distribution.

8. Analog Emulation: Many audio plugins aim to emulate the warmth and character of analog hardware equipment like vintage compressors, tape machines, and analog equalizers. These plugins allow users to achieve the 'analog sound' in a digital environment.

9. Real-time Processing: Some plugins offer real-time processing capabilities for live performances, enabling musicians and DJs to apply effects and manipulate audio in real-time during their performances.

Overall, audio plugins are essential tools for audio professionals, musicians, and producers, providing a wide range of functions to shape, enhance, and create audio in various creative and practical ways. They greatly expand the possibilities for audio production and sound manipulation in the digital realm."

Independent Audio Players using a Trigger

This page is dedicated to a returning questions of students:

Playing an audio file in the space is Easy, you just play it on your laptop or phone. But what if you are in some kind of exhibition setup and you want the sound to start playing if you pick up the headphones? Maybe like in a museum?

Depending on what you wat exactly and your level of technical expertise there are many routes to a suitable solution on this page you will find some suggestions for you.

"Smart" Headphones

There are some modern types of Bluetooth headphones that wil automatically pause when you take them off for example: 

  1. Sony WH-1000XM4 (probably there are many more Sony models that do this: These headphones feature a sensor that pauses music when you remove them.
  2. Bose Noise Cancelling Headphones 700: They pause music when you take them off.
  3. Sennheiser Momentum 3 Wireless: These headphones will auto-pause when you remove them from your ears.
  4. Apple AirPods Max: Apple's over-ear headphones feature auto-pause functionality when removed.
  5. Beats Solo Pro: These headphones pause playback when you take them off.

ATTENTION: These Headphones will PAUSE and will not stopt and then start again form the beginning!

Ready made Devices

There are some ready made device that you can buy that just might do what you need. The devices listed here are not tested by the author of this page.

BrightSign

One of the devices used in museums are BrightSign players. They are very robust and come in different flavours for audio & video. You can find the dedicated bookstack page here. At the HKU we have a number of these player's in the "Uitleen"

The cheapest BrighSign audioplayer is: BrightSign Interactieve audioplayer AU335 (192 euro)

Make it yourself

You can make it yourself with some off the shelf electronic components if you have some knowledge of these. There are roughly two ways:

Arduino way:

Use an Arduino and a MP3 player and hook them up with some wires and a button. Write the code to play the file when the sensor/button is triggered. (I use Arduino, but it cloud be a ESP, NodeMCU, raspberryPi pico) In the examples they often use a smal speaker, but that could also be a headphone. 

With the Arduino the most used mp3 player is the DFPlayer Mini

RaspberryPi way:

Take any RaspberryPi that can play audio then write a small python script that will listen for the GPIO ports and play a sound when thoe are triggered with a button. GPIO ports on a RaspberryPi are digital not analog.