Frequently Asked Questions

What is an impulse response? 

In the world of audio recording and more specifically guitar production, impulse responses (IRs) are used to digitally recreate the sound of a speaker cabinet, a room, a microphone, any and all processing in a signal chain, and the interaction between those elements. To do so, a full range frequency sweep is amplified through a cabinet, its signal chain, and recorded back into a DAW (digital audio workstation). Utilizing software, the recorded sweep is compared against the original sweep to define their differences. This process allows us to generate an IR as a single .wav file that can be loaded into IR hardware or software, giving the user a digital recreation of that recording setup and sound.

Folder and file hierarchy:

The impulse responses are organized within the encompassing collection’s folder. They are separated by a unique ID; album/session name, blends/microphone type, cabinet type, etc. Within each of those folders you will find various resolutions, choose the one that best suits your needs and platform. From there, both Blends and Assets are available. Blends are IRs built from an array of microphones, blended and processed to taste. This may include combinations of close microphones and room microphones, it will be labeled as such. Assets are the individual microphones used on the session. This enables you to use single elements of the equipment used on the session, as well as create new blends utilizing an IR loader (plug-in/software). 

How do I use my impulse response?

Impulse responses are used to simulate the cabinet and recording signal path of a guitar/bass chain. This means your instrument will need some sort of amplification to drive the IR. Your amp can exist as hardware or digital simulation. In either case, you can utilize these impulse responses though the approach will vary. 

To utilize your physical amp with an IR, a load box and IR loader are required. You can find both functions in single units, like the Mesa Cab Clone IR or Two Notes Torpedo Captor X. Ensure the impedance of your amp and load box match. Your amp’s speaker-out will drive the IR loader, resulting in an output of your desired IR that you can plug straight into your DAW or monitoring system. Follow the instructions specific to your IR loader for how-to upload and what resolutions are optimal. 

In the digital domain, your setup will exist either on a computer in a DAW/standalone program or in a dedicated amp simulator like Fractal Axe FX, Neural DSP Quad Cortex, etc. On your computer, you will need an amp simulator plug-in or program. Often, these will include a cabinet section you can load your own impulse responses directly into. If not, you will need an IR loader plug-in that your amp sim will feed. For physical units, follow the instructions the company has provided to upload your IRs. You may be required to download their proprietary software to make changes to your unit. In both cases, ensure the default cabinet/impulse response contained within the amp preset you are using is turned off once you’ve imported your new IR to hear the impulse response as intended.