One of the most popular features for Headrush Boards is the ability to use Impulse Responses with a board. What these are is a measured recording of the timbre of how a speaker played a note. On the most basic level, think of them as being a picture of one note of a song; all of the trebles, the bass, the presence of the sound; and your effects running through that picture, that one moment in time. 

In this guide we're going to talk about IR's, ultimately their differences between Cab Sims and Amp Clones, and where it's appropriate we'll give a small look into the basics of what they're doing to your setup



Amp Clones vs. Impulse Responses

Amp Clones and Impulse Responses are both recorded measurements to how a sound runs through an amplifier, and how you would record them is a very similar setup- Recorded tones run into an amp, get recorded by a mic after going through, and then are compared by a program for how the change to the sound is.

The difference between Amp Clones and Impulse Responses is, Amp Clones are a 3-dimensional picture of what an amp did to the sound, and require a certain amount of processing to be able to be able to manipulate how an amp influences a sound. It drives the sound and can manipulate the sound a way an amplifier does, and is imitating the influence of the amplifier on your sound.

By contrast, an Impulse Response is set with the colors it had while recording. If an amplifier drove the response of the speaker to distort a certain way, then the response of the speaker can not be changed, because the speaker had no control over how the amp drove it despite it being a part of the signal. There is equalization that can be done to accentuate certain parts of the sound, but these are simple contrast edits to the bigger picture; and as such the file does not require as much processing.

So when do you use an Amp Clone? When do you use an IR?

An IR is a moment in time, but ultimately not the entire character of your sound. Something still must come before it and drive the sound in your rig, as it is ultimately itself flat until sound goes through it. An Amp Clone is a processor driving your sound, amplifying and tempering it into what you want it to be. It will feedback if given the chance, because ultimately it adds itself wherever it can. 

But here's a fun feature of the Prime to consider- when finished with an Amp Clone of a combo, double tap the clone, and try turning off the cabinet. Try adding an IR after that, and see what kinds of new tones you can get yourself.

Cabinet Simulations vs. Impulse Responses

The Impulse Response's digital counterpart; what a Cabinet Simulation aims to do is to put the engineering side of an Impulse Response into your hands. What this ultimately does is takes the conditions that you would setup to record an IR and puts them into your hands- The way the speaker's response drove the mic, the microphone you're using, where the microphone is, etc. These are details you can tweak and edit endlessly until you find what you are lookin for.

As such, the sound you're getting is a little cleaner- an IR will always have a little more tone color because by it's very nature your setup goes into the IR, and the IR is a sound that was driven by an amp during it's response recording, especially with analog warmth factoring in. 

That being said, IR's are formulated often by sound recording engineers and enthusiasts who are meticulous over the details of replicating how the setup of a speaker should be recorded; and as such are great tools to be able to insert into a rig when searching for an original sound and pull from a different tonal variety.

So when do you use an IR vs. a Cabinet Simulation?

That question is down to personal preference- Do you have an ideal of what sound you're looking for? Then perhaps an IR would get you on your way faster. Are you looking for your own tone? Dialing in a Cabinet Simulation based off what you like is a good way to start. Is what you're hearing in your rig just missing something? Try an IR from a completely different setup. Is something missing some character? Try a Cabinet Simulation with a different mic setup.

Beginning with the Headrush 2.5, the ability to double your IR's and Cab Sims have become a common feature on all Headrush FX boards. What this means is that you can run two different Cabinet Simulations with two different microphone setups to create original tones completely under your control. Likewise if you have an IR pack that has two different IR snapshots for the same amplifier, you can run them in unison to create a picture of greater depth of the tonal characteristics of the speaker.

Questions? Concerns? Feedback? If you are still having trouble, please use the New Support Ticket button at the top to contact our support team for further assistance.