If you have ever wanted to try creating your own Impulse Responses, things have just got easier with the release of a free IR utility from Wave Arts for Mac and PC.

Convolution isn’t new but it is clever and if you explore all the possibilities it is a fascinating area. The plugins necessary to process your audio using convolution are readily available, from stock reverb plugins to premium offerings like Altiverb and Reverberate 3. Third party IRs are also freely available so if you want to experiment with alternative guitar cabinets for example, then download some cabinet IR’s and use a free IR loader like Fenrir from Aurora DSP. There is more to convolution than just reverbs and guitar cabinets, for example, you can capture the response of hardware equalizers, Waves’ Q-Clone is an excellent example of this approach.

A problem has always been how to create an IR in the first place. Premium convolution plugins offer this facility but free options have been harder to find. Deconvolver from Voxengo is an inexpensive plugin that does have a demo feature but is Windows only. For Mac users, the most common choice has been the IR Utility which ships with Logic Pro. While the utility is bundled with Logic Pro, Logic Pro is not free so it doesn’t really qualify as a free option.

Finding The IR Utility In Logic Pro

The IR Utility used to be found in the Utility folder. I was unaware that this was no longer the case until I looked for it recently. It is still available but is now a menu item in Space Designer. See the image below.

An excellent solution for capturing your own Impulse Responses has been provided in the form of the newly released MLsTool from Wave Arts. This utility is free and cross-platform. If you’ve ever wanted to experiment with IR capture this is is great way to get started.

What Is MLsTool?

MlsTool is an application used to measure impulse responses. You can use MlsTool to measure the room reverberation of acoustical spaces, or to measure digital effects units, speaker cabinets, spring or plate reverbs, etc. The impulse responses from MlsTool can be loaded into our ConvologyXT plug-in to reproduce the measured system.

MlsTools is distributed as a zip archive containing the application and a PDF manual. There is no purchase or registration required.

After unzipping the files, run the application and select Audio Settings to select the playback and recording devices. It’s recommended to use an external USB audio interface, and you should use the same audio device for both playback and recording, so that the sampling clocks for D/A and A/D conversion are perfectly synchronized. See the manual for more information.

After selecting the audio devices, choose an MLS length and click Start to begin the measurement. The app will play a few seconds of white noise, and will then write the measured impulse response to the file “impulse.wav”. At this point one generally repeats the measurement a few times while tweaking the output and input levels to get a good record level. When the levels are correct you can examine your impulse response in a sound editor, or load directly into Convology XT.

Specs:

• Maximum-length sequence (MLS) measurement application

• MacOS or Windows

• 24-bit WAV, 16-bit WAV or ACSII text output files

• Measures mono to mono responses, mono to stereo, and stereo to stereo (4-channel true stereo)

• Auto-crop

• IR lengths from 255 samples to 1M samples

• Supports any sampling rate provided by audio interface

Requirements:

• MacOS 10.8 and up

• MlsTool is a 64-bit MacOS application

• Windows 7/8/10

• MlsTool is a 32-bit Windows application

• It’s also recommended to use an external USB audio device for both playback and recording.