What an acoustic IR does
An acoustic IR is not a cab sim. A cab IR adds a speaker cabinet to an electric guitar; an acoustic IR does something different. It takes the sound of your acoustic's pickup and reshapes it toward the sound of that guitar recorded with a microphone in a room.
A pickup, especially a piezo under the saddle, hears the strings and the saddle up close. It tends to sound bright, sharp on the attack, a little thin in the body, and "quacky" in the midrange. A microphone hears the whole guitar: the top, the body resonance, the air around the soundhole. An acoustic IR is built by recording the same guitar through both its pickup and a good microphone, then capturing the difference between the two. When you load that IR after your pickup, it adds back much of what the mic hears and the pickup misses.
MultiTracks acoustic IRs are standard .wav files, captured from the acoustics used on the records. They load on any device or software with an IR loader, from flagship modelers to budget multi-effects and plug-ins.
This guide also covers violin and cello IRs. A violin or cello with a bridge pickup has the same problem an acoustic guitar does: the pickup hears the strings and bridge up close, and misses the body and air a microphone hears. String IRs solve it the same way. Everything in this guide, from expectations and pickup matching to loading, sample rate, and dial-in, applies to the Antonio & Allison String IRs and any other violin or cello IRs on MultiTracks. Where the guide says "guitar," read "your instrument." The Antonio & Allison IRs were made with a PZM-style contact pickup that sticks to the instrument's body, so they match best with that kind of pickup; bridge piezos will still improve, with more dial-in.
What to expect
An acoustic IR will not turn your pickup into a studio microphone. It will get you a long way there.
A well-matched acoustic IR takes a piezo or under-saddle pickup signal roughly 50 to 65 percent of the way to sounding like a miked acoustic. The pickup is still the source, so some of its character remains. What changes is the balance:
The harsh piezo attack softens. The spiky, glassy front edge of each note rolls off toward the rounder attack a microphone hears.
The body comes back. Low-mid warmth and the resonance of the guitar's top return.
The midrange quack calms down, and the whole guitar sounds more like an instrument in a room than a signal in a cable.
That difference is large, especially in a worship mix where the acoustic carries the song. On stage, it also gives you most of a miked sound without the feedback problems of a real microphone.
Your results depend heavily on your pickup. The next two sections explain why, and how to get as close to the demo as possible.
Know your pickup
An acoustic IR is made for a specific pickup sound. Different pickups hear the guitar in very different ways, so the same IR sounds different on each.
Pickup type | Where it sits | What it sounds like on its own | How acoustic IRs respond |
Under-saddle piezo (UST) | Under the bridge saddle | Bright, sharp attack, midrange quack, thin body | Biggest improvement; most acoustic IRs are built for this |
Behind-saddle or bridge-plate transducer | Behind the saddle or on the bridge plate | Warmer than a UST, still direct | Good improvement; may need less low-end from the IR |
Soundboard transducer | Stuck to the underside of the top | Woody, body-heavy, softer attack | Works, but can sound boomy; reduce lows |
Magnetic soundhole pickup | Across the soundhole | Electric-like, focused, strong low end | Works, but sounds least like the demo |
Internal microphone | Inside the body | Natural but feedback-prone | Often needs little or no IR |
Dual or blended systems (e.g. UST + internal mic) | Two sources mixed in the guitar or a preamp | Depends on the blend setting | Results change with every blend setting |
Dual systems need extra care. Many modern guitars and aftermarket systems mix two sources, such as a piezo and an internal microphone. The IR behaves differently at every blend position. For the most predictable result, set the blend to the source the IR was made with.
Matching the pack for demo-accurate results
Producers capture acoustic IRs in different ways, and not every producer on MultiTracks tells us which pickup an IR was designed for. When a pack's product page or readme names the guitar, pickup, and pickup setting, match them as closely as you can to hear what you hear in the demo. When it does not, the IR will still help any pickup; start with your under-saddle pickup, since most acoustic IRs are built for that sound, and use the dial-in steps below.
Example: Anthony Catacoli's 914 IR Pack. Anthony uses a proprietary capture method that compares a microphone directly against the guitar's under-saddle pickup, so each IR captures the exact difference between that pickup and the mic. The IRs were made with an LR Baggs Anthem system set to its under-saddle pickup only. To get results closest to the demo:
If your guitar has an LR Baggs Anthem, set it to the under-saddle pickup only (no internal mic in the blend).
If your guitar has an LR Baggs Element, you are already on the same kind of under-saddle pickup; use it as is.
If you have a different pickup, the IR will still help, but it will not match the demo exactly. Use the dial-in steps below to close the gap.
This is not about one brand being right. It is about physics: an IR captures the difference between one specific pickup and one microphone. The closer your pickup is to the one in the readme, the closer you get to the demo. Whatever pickup you have, experiment, EQ, and trust your ears.
Where acoustic IRs work
Any IR loader plays MultiTracks acoustic IRs, flagship to budget. Three families of gear are worth knowing:
Guitar modelers and multi-effects. Helix, HX Stomp, POD Go, Helix Stadium, Fractal, Kemper, Quad Cortex, ToneX, HeadRush, and budget units from Mooer, Nux, Hotone, Sonicake, and Valeton all have IR loaders. Run your acoustic into the unit, skip the amp, and put the IR first. Our electric-guitar guides cover each platform's loading steps.
Acoustic IR pedals and preamps. Some acoustic pedals are built around IRs. Several of them, such as the LR Baggs Voiceprint DI, ToneDexter, and Nux Optima Air, create a custom IR of your own guitar by measuring it with a microphone or phone. Those custom IRs are matched to your exact guitar and are excellent if you have the time to make them. Check each pedal's documentation to see whether it also loads third-party .wav IRs like ours.
Software. Any IR loader plug-in in your DAW, or a modeler plug-in with an IR block, plays acoustic IRs for recording or for running a live rig from a computer.
MultiTracks acoustic IRs give you a mic sound captured from a great guitar by a producer, ready to load in seconds, with no measuring session.
For front-of-house, monitor, and streaming engineers
Acoustic instrument IRs are not only for players. They are one of the most useful tools a church sound team can have, because they fix the sound of a pickup at the board without changing anything on stage.
Front of house. Insert an IR loader on the acoustic guitar, violin, or cello channel and the instrument sits in the mix like a miked source, without a microphone on stage to feed back or pick up the drums.
Monitors and in-ears. A more natural acoustic in the musicians' ears helps them play with better feel and less fatigue. Use the same IR as front of house, or a lighter blend.
Streaming and broadcast. Online audiences hear the acoustic on headphones and small speakers, where piezo harshness stands out most. An IR on the stream mix makes the biggest difference of all.
How to run them. Some digital consoles and their plug-in racks can host an IR loader that imports .wav files. Many churches run one through a plug-in host connected to the console, such as a Waves SoundGrid or SuperRack system with an IR loader, or a computer running any IR loader plug-in. Check your console's documentation for plug-in or IR support.
Watch latency. Convolution adds a small delay on some systems. Use a low-latency or zero-latency mode where available, especially for in-ear mixes, and check that the processed channel stays in time with the rest of the band.
Sample rate, length, and one IR or two
Everything in the MultiTracks cab IR guide about sample rate, IR length, and conversion applies to acoustic IRs too. In short:
Sample rate is how many times per second the audio was measured (44.1, 48, or 96 kHz). The IR must match the rate your device runs at; most editors convert automatically.
IR length is how much of the response the file holds. Acoustic IRs carry body resonance and some room, so they benefit from longer lengths more than cab IRs do. Use the longest length your device supports.
Use the native version when the pack has it. If the pack includes a file at your device's native rate and length, load that one; it needs no conversion. If not, load the closest one and let your editor convert it.
Check your loader if it does not convert. Some loaders, like the Strymon Iridium's Impulse Manager, accept only their own format (96 kHz, up to 500 ms). Others, like the Walrus Audio ACS1's web app, convert for you.
One IR or two. An IR is a mono signal: one mic on one guitar. Loaders that hold two IRs either blend them into one sound or play them in stereo, one per side. For acoustic, two IRs work well blended (a body mic and a neck mic) or in stereo for in-ear mixes. A single loader loses nothing: our blended IRs give you a two-mic sound in one file. See the cab IR guide for the full table of loader types.
What you get in a MultiTracks acoustic IR pack
.wav IRs captured from the acoustics used on the records, each naming the guitar, the microphone, and its position.
The pickup and setting used to make them, stated on the product page and in the readme when the producer provides it (for example, LR Baggs Anthem, under-saddle only). Not every producer does.
Single-mic and blended IRs where the producer made them.
Sample rate and length labels on each file or folder. Not every pack includes every format; your device's editor converts the rest, except loaders that do not convert.
A readme with the guitar, pickup, mic, and suggested starting EQ.
Loading acoustic IRs
Pick the right version for your device's native sample rate and length.
Import the IR with your device's editor, app, or file transfer. See the MultiTracks guide for your platform.
Build the chain: pickup → (optional preamp or compressor) → acoustic IR → EQ → reverb, delay, and other effects. The IR goes early, right after the pickup signal, so everything after it processes a mic-like sound.
Bypass any amp or cab model. An acoustic IR replaces the amp and cab, not adds to them.
Save the preset.
On a modeler, turn the IR's mix to 100 percent to start. Many loaders also let you blend the IR with the dry pickup signal; see Dialing it in.
Dialing it in
The IR does most of the work. These adjustments close the rest of the gap for your guitar and your room.
Match the pickup setting. On a blended system, set it to the source named in the readme before you touch anything else.
Set the input level. Play hard and make sure the loader's input is not clipping. Piezo pickups have sharp peaks; a clipped input sounds brittle no matter which IR you use.
Try the mix control. Start at 100 percent IR. If you want more definition or pick attack back, blend in some dry pickup (many players settle between 70 and 100 percent).
EQ after the IR. A low cut around 80 to 100 Hz controls boom and stage feedback. If it is still harsh, a gentle cut around 2 to 4 kHz tames remaining piezo edge. Small moves work best.
Watch for feedback. IRs bring back body, and body resonance is where acoustic feedback starts. Keep the low cut on, use a notch filter or phase switch on your preamp if you have one, and keep stage volume reasonable.
Mind the room. If the IR includes room sound, go lighter on reverb, or turn the reverb off and let the IR do the work.
Experiment. Two players with the same IR will land in different places because their guitars, strings, and pickups differ. There is no wrong setting if it sounds and feels right to you.
Troubleshooting and FAQ
It does not sound exactly like the demo. That is expected unless your guitar and pickup match the pack. If the readme names a pickup and setting, match it if you can. Either way, use the dial-in steps to close the gap.
It sounds boomy or feeds back on stage. The IR brought back low-end body. Raise the low cut, reduce the IR's level or mix, and use your preamp's notch or phase controls.
It still sounds quacky or harsh. Check that the loader input is not clipping, then try a gentle cut around 2 to 4 kHz after the IR. A different IR from the pack, especially a blended one, may suit your pickup better.
It sounds thin or small. The sample rate likely does not match your device and was not converted. Load the native version.
My guitar has a blended system. Which setting do I use? The one the readme names, if it names one. For Anthony Catacoli's 914 IR Pack, that is LR Baggs Anthem on under-saddle only. If the pack does not say, start with under-saddle only and compare by ear.
Can I use an acoustic IR with an amp or cab model? No. Bypass them. The acoustic IR replaces the amp and cab.
Will acoustic IRs work on my budget multi-effects? Yes. Any IR loader plays them.
My acoustic pedal makes its own IRs. Do I still need these? Not necessarily. Custom IRs of your own guitar are excellent. MultiTracks IRs give you a producer's mic sound from a great guitar without a measuring session, and many players keep both.
What to look at next
Any acoustic player with an IR loader: MultiTracks acoustic IR packs, labeled with the guitar and pickup when the producer provides them.
Players with an LR Baggs Anthem or Element: Anthony Catacoli's 914 IR Pack, made on the Anthem's under-saddle setting.
Violin and cello players: the Antonio & Allison String IRs.
Church sound teams: acoustic and string IRs for front-of-house, monitor, and stream mixes.
Electric players: MultiTracks cab IRs and capture packs; see the cab IR guide and the device guides: Line 6, Kemper, Neural DSP, IK ToneX, Fractal, and HeadRush.