If you are a guitar player who wants to get the best possible tone from your amplifier, you might have heard of impulse responses. But what are they exactly, and how can they help you achieve your sonic goals? In this article, we will explain what impulse responses are, how they work, and how you can use them for recording and live performance. We will also introduce some free tools and resources that you can use to get started with impulse responses right away.
What are impulse responses?
An impulse response (IR) is a digital representation of how a sound source interacts with a physical space or an audio device. For example, an IR can capture how a guitar cabinet sounds in a specific room, or how a microphone picks up the sound of a speaker. An IR can also capture how an audio processor, such as an equalizer or a reverb unit, affects the sound.
An IR is usually created by playing a short burst of sound (called an impulse) through the system that you want to capture, and recording the resulting sound. The impulse can be anything from a click to a sweep of frequencies. The recorded sound is then processed to remove the original impulse and isolate the system’s response. The resulting file is the IR, which can be stored and used later.
How do impulse responses work?
An IR works by applying the captured response of a system to any sound source that you want to process. For example, if you have an IR of a guitar cabinet in a room, you can use it to make any guitar signal sound like it is coming from that cabinet in that room. This way, you can simulate different speaker models, microphone placements, and room acoustics without having to physically change anything.
To use an IR, you need a software or hardware device that can load and apply it to your sound source. This device is called an IR loader. There are many types of IR loaders available, ranging from free plugins for your digital audio workstation (DAW) to dedicated pedals for your pedalboard. We will discuss some of them later in this article.
Why use impulse responses?
Impulse responses can offer many benefits for guitar players who want to get the most out of their tone. Here are some of them:
– Impulse responses can give you access to a wide variety of sounds that would otherwise be difficult or expensive to obtain. For example, you can use IRs to emulate rare or vintage speaker cabinets, microphones, or effects units that you don’t own or have access to.
– Impulse responses can save you time and hassle when recording or performing live. Instead of having to set up and mic up your amp and cabinet every time, you can simply plug your guitar into an IR loader and get a consistent and high-quality sound. You can also easily switch between different sounds without having to change any physical settings.
– Impulse responses can help you achieve a more realistic and natural sound when using digital amp modelling or direct injection (DI). By adding an IR of a real speaker cabinet and room to your signal chain, you can avoid the harshness and artificiality that sometimes plague digital guitar tones.
– Impulse responses can help you shape your tone according to your preferences and needs. You can mix and match different IRs to create your own custom sounds or tweak them using EQ or other effects. You can also use IRs to correct or enhance the sound of your existing amp or cabinet.
How to use impulse responses?
To use impulse responses for your guitar tone, you need two things: an IR loader and some IR files. An IR loader is a device that can load and apply an IR to your guitar signal. An IR file is a digital file that contains the captured response of a system that you want to emulate.
There are many options for both IR loaders and IR files, depending on your budget, preferences, and setup. Here are some examples:
Free VST IR loaders
If you are recording or playing through a computer, you can use a free plugin that acts as an IR loader for your DAW. Some popular ones are:
– NadIR by Ignite Amps: A simple and easy-to-use plugin that lets you load two IRs at once and blend them together. It also has some basic controls for phase, delay, pan, and volume.
– LeCab 2 by LePou: A versatile plugin that lets you load up to six IRs at once and mix them together. It also has some advanced features such as high-pass and low-pass filters, latency compensation, oversampling, and stereo processing.
– Pulse by Lancaster Audio: A sleek plugin that lets you load one IR at a time and adjust its level, polarity, and phase. It also has a built-in IR browser and a handy feature that lets you switch between different IRs using MIDI.
IR loader pedals
If you are playing through a physical amp or a pedalboard, you can use a dedicated pedal that acts as an IR loader for your guitar signal. Some popular ones are:
– Mooer Radar: A compact and affordable pedal that lets you load up to 30 IRs and store them in presets. It also has some built-in EQ and power amp simulation options, as well as a headphone output and a USB port for loading IRs from your computer.
– Two Notes Torpedo C.A.B. M+: A powerful and versatile pedal that lets you load up to 128 IRs and store them in presets. It also has some built-in amp and cab simulation options, as well as a comprehensive EQ section, a headphone output, an XLR output, and a USB port for loading IRs from your computer or using the Torpedo Remote software.
– Sonicake IR: Super budge IR loader, with balanced XLR output and 11 slots for IRs. Comes with some great and very usable IRs preloaded.
Free impulse response examples
To get started with impulse responses, you need some IR files that capture the sound of the systems that you want to emulate. There are many sources of IR files online, ranging from paid to free. Here are some examples of free IR files that you can download and use for your guitar tone:
– Celestion: The legendary speaker manufacturer offers some free IR files of their most popular models, such as the Vintage 30, the Greenback, and the Creamback. You can choose from different cabinet types, microphone types, and microphone positions.
– Redwirez: Another well-known IR producer offers some free IR files of their BigBox series, which features some classic and rare speaker cabinets. You can choose from different speaker models, cabinet types, microphone types, and microphone positions.
– God’s Cab: An amazing IR collection from every possible position on a Mesa cab (My Favorite!!)
Impulse responses are a powerful and convenient way to enhance your guitar tone and achieve a wide variety of sounds. By using an IR loader and some IR files, you can emulate different speaker cabinets, microphones, rooms, and effects without having to physically change anything. You can also shape your tone according to your preferences and needs by mixing and matching different IRs or tweaking them with EQ or other effects.
Whether you are recording or playing live, impulse responses can help you get the best possible sound from your amplifier. If you haven’t tried them yet, we encourage you to do so and explore the possibilities that they offer.
We hope this article has been informative and helpful for you. If you have any questions or comments, feel free to leave them below. Happy playing!
Also published on Medium.
