Interesting in hearing from people who use IRs with acoustic guitar

[Markcarl]

I recently got an Axe-Fx iii modeler. I’m having a lot of fun with it! I got it primarily to use with my electric guitars. I noticed the Axe-Fx uses impulse response (IR) / tone matching to model the sound of different speaker cabinets. I recently found there are IR files for mic’d acoustic guitars and these can be used with the Axe-Fx to model the sound of a mic’d acoustic guitar with a piezo / magnetic pickup equipped guitar as the input source.

I bought a set of IR files from 3 Sigma Audio that were created with a Martin D45 and have been experimenting with using them on the Axe-Fx with a piezo equipped acoustic. The output I’m getting when using the IR files is a big improvement over the results I get when just using the piezo pickup.

I know there are a number of systems out there (Fishman Aura, Tonex, Line 6 Helix, Axe-FX, …) that acoustic guitarists are using to try and approximate the sound of a mic’d acoustic when playing an acoustic guitar with a pickup.

I’m curious, how many of you use IRs with acoustic guitar when performing live, recording, or practicing? What systems do you use? How well do you think it’s working? I’m new to impulse responses and the Axe-FX.

[Cuki79]

Check my webpage

acousticir.free.fr

You can also capture the IR file from your very own guitar thanks to the free online app.

[Markcarl]

Originally Posted by Cuki79

Check my webpage

acousticir.free.fr

You can also capture the IR file from your very own guitar thanks to the free online app.

Thanks! I’ll check out your site. I like the idea of trying to match the sound of one of my own guitars.

[TedBPhx]

I do not understand IRs. If I create a map of the tone then shape the sound of the guitar to that tone as an IR does then what happens if I change tone like with pick attack or type or position over the sound hole or grip strength or any of the million ways acoustic players adjust tone. They all map back to one IR. Don’t get it.

[Cuki79]

Originally Posted by TedBPhx

I do not understand IRs. If I create a map of the tone then shape the sound of the guitar to that tone as an IR does then what happens if I change tone like with pick attack or type or position over the sound hole or grip strength or any of the million ways acoustic players adjust tone. They all map back to one IR. Don’t get it.

The IR does not depend on the pick attack or position.

When you capture an IR you compare two wave files coming from a single recording. It is very important that both tracks are recording from the same performance.

• wav file n°1 is the pickup track. It includes fingers, pick, bridge, pickup and preamp if there is any.
• wav file n°2 is the mic track. It includes fingers, pick, bridge, guitar top vibration, box, air, microphone and preamp.

This is illustrated by the figure below


The algorithm compares both tracks and look for the difference between both. Finger and picks contributions cancel themselves. What you have left is the tranformation that turns the pickup tone into the guitar top+box+air+mic tone.

When you apply the IR file with an IR pedal, you do that transformation as shown by the figure below

[guitarman68]

Originally Posted by Markcarl

I’m curious, how many of you use IRs with acoustic guitar when performing live, recording, or practicing? What systems do you use? How well do you think it’s working? I’m new to impulse responses and the Axe-FX.

I own a ToneDexter which I use from time to time, still my Grace Felix 2 preamp gets most of the use (internal pickup / external mic on a stand - combo).

The IRs on the ToneDexter are created in my studio with the particular guitar and pickup. I have to say it works great with under saddle transducers and soundboard transducer. More recently I started more experimentation again, and - as many here experienced before - the weaker / unnatural the pickup sounds the more you will benefit from using IRs. Just yesterday I tried it with a passive under saddle pickup in a YAMAHA LL16 guitar, created two or three wave maps with the TD and compared it directly to the miked guitar - what a delight.

I also own some Dazzo- or Schatten HFN - equipped guitars. There is no significant improvement in using IRs here because these pickups already sound very natural and accurate.