Impulse Response (IR)

What is an Impulse Response?

An Impulse Response (IR) is a digital snapshot of how a speaker cabinet, room, or space responds to sound. Think of it as an audio fingerprint that captures the acoustic characteristics of everything from a vintage 4x12 Marshall cabinet to a cathedral's natural reverb. When you load an IR into your amp modeler, plugin, or pedalboard, it processes your guitar signal through that captured acoustic signature, giving you the sound and feel of the real thing. IR's are the industry-standard technology for capturing speaker cabinets, microphone placement, and room acoustics with remarkable accuracy.

Who are Impulse Responses for?

Impulse Responses are for guitarists, bassists, producers, and engineers who want professional cabinet and room tones without the expense and hassle of owning the physical gear. IR's give you instant access to legendary speaker cabinets, boutique cabs, and studio-quality room acoustics. Impulse responses are widely used among bedroom producers, touring musicians and professional producers.

What are the benefits of Impulse Responses?

Impulse Responses deliver professional cabinet tones instantly, without the cost, weight, or recording challenges of physical speaker cabinets. You can swap between a vintage Celestion-loaded 4x12, a boutique 2x12, and a bass 8x10 in seconds. IR's give you access to perfectly mic'd cabinets captured in world-class studios with premium microphones you might never own. They're essential for silent recording, consistent live tone, and exploring hundreds of cabinet combinations without moving a single speaker. IR's also capture reverb, delay, and room ambience, making them invaluable for producers and mixers.

How does an Impulse Response work?

An Impulse Response works by capturing the acoustic signature of a speaker cabinet or space using a special test signal. Here's the process:

• Test Signal: A short impulse signal (or swept sine wave) is played through the speaker cabinet, microphone, and room setup you want to capture
• Recording: The output is recorded, capturing how the cabinet and room color the frequency response and add natural resonances
• Processing: Deconvolve (mathematically remove) the known input signal from the output recording, leaving a .WAV file that represents the acoustic signature
• Convolution: When you load the IR, your guitar signal is processed through convolution – a mathematical operation that applies the cabinet's frequency response and time-domain characteristics to your sound in real-time

Diagram of an IR capture

Unlike amplifier modeling which must handle complex nonlinear distortion, IR's capture linear systems, making them smaller files and extremely CPU-efficient. A typical IR file is only a few milliseconds long but contains all the information needed to replicate the speaker cabinet's sound.

What’s the difference between NAM and IR's?

Neural Amp Modeler and Impulse Responses work together but capture different parts of your signal chain. NAM captures the amplifier, pedals, and preamp section – modeling how the gear distorts, compresses, and colors your tone. IR's capture the speaker cabinet, microphone, and room acoustics – the final stage that shapes your sound.

NAM handles the nonlinear, dynamic behavior of amps and pedals, while IR's capture the linear frequency response of speakers, spaces and reverb. You can use both in tandem: a NAM profile for the amp head and an IR for the cab. This combination gives you a hyper-realistic guitar tone from input to output.

Important: If you're using a NAM capture of just an "Amp Head," you'll need to pair it with an IR to add the speaker cabinet. Without an IR, your tone will sound thin and harsh. NAM captures labeled "Full Rig / Combo" already include the speaker cabinet, so no separate IR is needed.

What hardware and software supports impulse responses?

IR's are the universal standard for cabinet simulation, supported by virtually every major amp modeling platform. Software support includes Neural DSP, Helix Native, STL Tones, Amplitude, Guitar Rig, BIAS FX, Bogren Digital, ML Sound Lab, and the free NAM Plugin.

Hardware platforms that load IR's include Line 6 Helix, Fractal Audio Axe-FX, Kemper Profiler, Quad Cortex, HX Stomp, Headrush, Boss GT-1000, and Hotone Ampero. Even analog tube amps can use IR's through products like the Strymon Iridium, Two Notes Torpedo, and Mooer Radar. This widespread compatibility means you can use your favorite IR's across a wide range of software and hardware.

Why use TONE3000 for Impulse Responses (IR's)?

TONE3000 is the world's largest community for discovering, sharing, and creating Neural Amp Modeler profiles and impulse responses (IR's).

How do I get started with IR's and NAM?

Getting started with Impulse Responses and Neural Amp Modeler is simple. Download the free NAM plugin for your DAW, then grab IR's from TONE3000. Load a NAM profile of an amp head into the NAM plugin, then load an IR of a speaker cabinet into the plugin's IR loader section. Connect your guitar through an audio interface, and you'll instantly hear a complete amp-and-cab tone.

You can start with classic combinations like a Marshall amp with a Greenback 4x12 IR, or a Fender amp with a vintage Jensen speaker IR. Experiment with different microphone positions and room IR's to find your perfect sound. The TONE3000 community offers thousands of free NAM profiles and IR's to explore.

First time? We created a helpful guide.