A cab impulse response (IR) is a short audio file that captures how a real speaker cabinet, microphone, and mic position color a guitar signal. Put an IR after an amp model, a DI amp capture, or a preamp pedal, and you hear that cabinet as if it were miked in the room. Change the IR and you change the speaker, the mic, and the placement without touching the amp.

MultiTracks IRs are standard .wav files. They load on any device or software with an IR or cab loader: flagship modelers like Helix, Axe-Fx, Kemper, Quad Cortex, ToneX, and HeadRush; budget multi-effects from Mooer, Nux, Hotone, Sonicake, and Valeton; amp-simulator pedals with built-in IR loaders like the Walrus Audio ACS1 and Strymon Iridium; and free or paid IR loader plug-ins on your computer. If your gear loads IRs, it loads ours, whatever it cost.

The two specs that matter when you load an IR are its sample rate and its length. The next two sections explain both in plain terms.

Sample rate is how many times per second the audio was measured, written in kilohertz (kHz). An IR recorded at 48 kHz holds 48,000 measurements for every second of sound. The common rates are:

Why it matters: an IR has to match the sample rate your device runs at. A 44.1 kHz IR played back on a 48 kHz device without conversion sounds slightly wrong: the cabinet's tone shifts up, as if the speaker shrank. Good loaders prevent this by converting the IR to their own rate when you import it. A higher sample rate is not automatically better on your device; what matters is that the IR matches the rate the device actually runs.

IR length is how much of the cabinet's response the file holds, counted in samples (or in milliseconds). Longer IRs capture more of the cabinet's low-end resonance and the way the sound decays; shorter IRs use less processing power.

The same number of samples covers a different amount of time at different sample rates: 2,048 samples is about 43 ms at 48 kHz but about 21 ms at 96 kHz. That is why loaders often talk about length in milliseconds.

In a full band mix, most players cannot hear the difference between 1,024 and 2,048 samples. Use the longer version when your device has the processing to spare.

Not every IR producer exports every IR at every sample rate and every length, and you do not need them to. Most modern devices and editors convert the IR for you when you import it: they resample it to the device's rate and trim or extend it to the device's length.

Conversion works well, but it is still a change to the file. So follow one simple rule:

If the pack includes a version at your device's native sample rate and length, load that one. It plays exactly as the producer made it, with no conversion after the fact. If your exact version is not in the pack, load the closest one and let your device's editor convert it.

To find your device's native spec, check the platform table below or your device's manual. If a device or app does not say whether it converts, assume it does not, and load the 48 kHz version, which is the safest choice for most guitar hardware.

This is what we have confirmed from each manufacturer's documentation as of October 2026. "Converts automatically" means the editor or device resamples and resizes the IR on import, so any MultiTracks version loads correctly.

On the computer, most IR loader plug-ins and DAWs also convert on the fly to match your session's sample rate. For platform-specific loading steps, see the MultiTracks guide for your device.

Amp-simulator pedals with built-in IR loaders, and standalone IR loader pedals, vary more than full modelers do. On an amp-sim pedal there is no separate cab model to fall back on: the IR is the cabinet, so loading the right version matters even more. Some convert any IR you give them; others expect a specific sample rate and length and may play a mismatched file incorrectly or refuse it. Before you load MultiTracks IRs into one of these, check your device's documentation for two things:

If the answer to the second question is no or unclear, load the MultiTracks version that matches the device's native spec.

Two popular examples:

The same applies to other IR pedals (Two Notes, Mooer, Hotone, Joyo, and others): check the spec, load the matching version, and when in doubt, use 48 kHz.

MultiTracks IRs are mono unless labeled stereo. Many loaders that play one IR at a time keep only the left channel of a stereo file. See One IR or two below for how loaders handle blends and stereo.

Every IR loader follows the same pattern:

Platform-specific steps are in each MultiTracks guide: Line 6, Kemper, Neural DSP Quad Cortex, IK ToneX, Fractal, HeadRush, and NAM. For a computer, load the .wav into any IR loader plug-in after your amp sim.

A cab IR is a mono signal at heart: it captures one microphone on one speaker. Some files are labeled stereo, but a stereo IR is really two mono captures (two mics, or two positions) packaged together in one file. How many IRs you can run at once, and what happens to them, depends entirely on your loader, not on the IR.

Loaders handle a second IR in one of three ways:

Check your device's manual to see which it offers. If your loader takes only one IR, you lose nothing: MultiTracks blended IRs give you the two-mic sound in a single mono file. If it takes two, try pairing a close-mic IR with a distant or ribbon-mic IR from the same cab, then match levels and check the phase (see below).

My device will not accept the file. It may only take a specific sample rate, bit depth, or length. Check its manual and load the matching MultiTracks version. If none matches, convert the file in any DAW (export as mono .wav at the device's rate) or contact our support.

The IR sounds thin, small, or too bright. The sample rate likely does not match your device and the device did not convert it. Load the version at your device's native rate.

It sounds muffled. There is a second cab in the chain: an Amp + Cab capture, a profile with a cab, or a real guitar speaker. Remove one.

I loaded a 96 kHz IR on a 48 kHz device and it sounds fine. The editor converted it. That is normal and fine; the native version is still the purest option when available.

Should I use 1,024 or 2,048 samples? Use the longest your device supports without running out of processing. In a band mix, the difference is small.

Do MultiTracks IRs work on budget pedals? Yes. Any device with an IR or cab loader plays them.

Can I use MultiTracks IRs with NAM, ToneX, Neural, or Proxy captures? Yes, after any capture labeled DI or Amp only. Skip them after captures that include a cab.