Impulse Response Guitar Pedals: IR & Cab Sims Explained

Find out all about Impulse Responses, Cab Simulators, and the pedals and gear which allow you to use these innovative bits of technology.

In this blog we’ll discover the answers to the following questions:

• What is an Impulse Response?
• Why is an Impulse Response so useful?
• What pedals use Impulse Responses?
• What are the best Impulse Response guitar pedals?

So if you’re looking to get started with IR - or searching for some new ways to mix up your tone - keep reading to find out how to use Impulse Response guitar gear and which IR pedals are best for your rig..

An impulse response is a representation of a guitar sound and signal chain. It captures the qualities of the speaker, mic, and room simultaneously in order to allow these variables to be recreated in the studio or on-stage.

An Impulse Response is captured by sweeping across the entire frequency range (typically 20Hz to 20kHz) with the set-up as you would like to recreate it. So once you’ve found the perfect amp, preamp, cab, mic, mic position, and room - everything that makes a guitar tone sound the way it does - you can recall this simply with an IR.

The difference between an Impulse Response and a Cabinet Simulation is that a Cab Sim is usually little more than an EQ curve applied to the output of the signal which aims to replicate the properties of the relevant cabinet. On the other hand, an Impulse Response is able to much more accurately represent each of the components which makes up the complete tone of the guitar.

Impulse Responses are useful because they allow you to try out a huge array of guitar sounds that you wouldn’t normally have access to.

Instead of taking a selection of cabinets and microphones into a range of different rooms in order to track the perfect sound for your recording, you are able to plug directly into your computer and try out all of the different Impulse Responses that have already been made.

So whilst you might never get to record an album at Abbey Road, you can try out an Impulse Response made within one of the studios and instantly hear how your guitar would sound in that space, through the same rig and with the same mics that were used to capture the Impulse Response.

Impulse Responses are also infinitely useful when playing live. Instead of having to rely on the mics, backline, and room sound at a venue, you can plug directly into the mixing desk and unleash the exact same tone that you use for recordings, rehearsals, and everything else.

This is also useful if you’re playing a smaller venue which can’t handle the necessary volume of certain amps. Whilst usually this might mean you miss out on the natural saturation or ‘break-up’ of your tone, by recalling an Impulse Response you can still achieve the same sounds but at any volume.

You can also switch between IRs for different songs and sections, giving you complete flexibility when you need it most.

Impulse Responses have been used as DAW plug-ins for some time, and many guitarists have come to rely on modelling amps (such as Kemper Profilers) for their IR tones.

Fortunately for us, Impulse Response technology is now a much more readily-available feature of guitar gear, especially when looking for pedals and pedalboard-friendly options.

Some pedals are specifically-designed for loading and storing IRs, whereas other pedals have IR-loading as a feature amongst other FX and modelling capabilities.

Guitar pedal heavyweights such as BOSS and Strymon have both entered the IR arena, with other options from the likes of Two Notes and Line 6.

Here we’ll be looking at some of our favourite options for getting the best Impulse Response guitar tones and how you can add them to your pedalboard..

Our first pick for the best Impulse Response guitar pedal comes from Strymon.

The Iridium Amp and IR Cab Simulator fits snugly at the end of your pedalboard, boasting amp-style controls for shaping 3 "Matrix Modelled" amps based on the Fender Deluxe, the VOX AC30TB brilliant channel, and the Marshall Plexi Super Lead '59.

There are also 9 IR Cabinet models with Room control for full flexibility and versatility of your sound.

Another awesome option comes from Two Notes and their range of Torpedo C.A.B Virtual Cabinet Simulator Pedals.

The C.A.B M+ comes with 32 of the most highly-regarded cabs, 8 intricately-responsive mics, and 8 rooms to choose from. Furthermore, you can pick from a range of valve options and experiment with onboard power amp emulation, allowing you to create a bespoke sound for your set.

Plus, with the latest firmware you'll get access to a broad library of professional effects such as reverbs, EQs, gates and much more.

If you want to use modelling FX instead of combining an IR pedal with your existing stompboxes, then we also recommend checking out Headrush, Kemper, and the Line 6 Helix range here:

Impulse Response guitar pedals are an infinitely useful tool for the modern guitarist to take advantage of. Whether you’re a recording artist looking to experiment with different amp, mic, and room configurations, or a live musician in need of more control on tour - check out all of our Impulse Response Guitar Pedals at PMT here:

Want more information on the range of guitar amps at PMT? Want to check out the latest electric guitars, amps, and effects at PMT? Call us on 0151 448 2089 or check out your local store to speak to one of our Experts about your needs.