Impulse Responses

A: The non-technical answer to this question is that an IR is a snapshot of a speaker cabinet’s linear characteristics. For speaker cabs, this means frequency, edge response, and phase response. In even simpler terms, an IR you download from our website is a speaker cabinet emulation that is inserted in your signal chain after your amp simulator.

A: In order to make an Impulse Response, we need to get the physical cabinet into our studio. Then, using an assortment of microphones, pre’s, and power amps, we work our magic to create the resulting .WAV we are known for. A common misconception is that an IR is simply an EQ curve. This is false. An Impulse Response captures the very way the cabinet responds to an input signal and is affected by all details of the cab, from the speakers, configuration, cabinet size, the wood of the cabinet, etc.

A: Version A is captured with one power amp, and B with another. While both versions are very similar, they offer slightly different dynamic response. The “A” power amp is tube based and is known for it’s smooth and non-harsh characteristics, especially in the top end, while the “B” power amp is also tube based, but is known for its wild and aggressive characteristics.

A: The IR packs you purchased must be loaded into an IR loader. An IR loader is a plugin that allows you to load in the .WAV files you purchased. The IR loader is always put after the amp sim plugin (or signal from a real amp through a load box). We offer a free IR loader, PULSE, which is provided in all common plugin formats. We highly recommend using PULSE, but know that there are other IR loaders available.
If you’ve added the .WAV files to your plugin directory, remove them and put them and create an Impulse Response folder on your computer. This should help organize the collection of IR’s you may accumulate.

A: We provide files for use in the Fractal Axe-FX line of products as well as for the Kemper profiling amp. If you have a piece of hardware that can load IR’s, ours will probably work. We however cannot offer support for any hardware.

A: Some IR loaders (our own included) will be able to handle the 96K IR’s contained in the WAV folder. In the case of certain pieces of hardware or with amp sims such as Scuffham S-Gear, real-time sample rate conversion cannot be performed, and the IR’s sample rate must match your sessions.

Kemper Profiles

A: A lot of testing went into this before we settled on a method. We ultimately determined our IR’s could not be picked out from an A/B test with a mic’s signal, and thusly chose to capture the amplifier through use of a high quality reactive load box paired with an IR we made either for the kemper profile to match or from our library. This also offers expandability, as the user can swap out cabs for different tone flavors.

A: Simple! We did not force any tones out of an amp we did not expressly feel it could achieve.


A: Simply click on the active A or B button and it will put you back into blend mode.

A: No. And why would you want to use any loader but PULSE?

Website & Payments

A: No. We do however happily consider NFR’s for artists/press, contact us for more info.

A: We’re trying to figure out a more intuitive way for this to work with our webstore, but for now, just email us with both proofs of purchase and we will be happy to exchange the IR’s you already own with IR’s or equal/lesser value.