IRs

[clivea]

I’ve been reading about lmpulse Responses (IRs) and it got me wondering if any of our members were using these?

Clive

[Garystrat]

Many of us have been using them for years, the basic sampling principles remain the same, but the technology is evolving to more sophisticated techniques, i.e. speaker Z curve response to model the complex coupling at component level amp output, the ability to mix and match multiple IR’s (in a convolver - see below) and there are also dedicated dynamic response IR’s intend to provide a more natural amp response and feel to playing style.

Whilst there are a few dedicated hardware units that can handle IR’s, the most common use is in software based amp sims and most can now load standard IR’s within their own plugin. However, these tend to be more basic and there are dedicated IR plugins for either multiple IR use or ones for specialised IR’s that will only run within their own “convolver”, this is an associated term used for devices or plugins that load IR’s.

Examples of software that has advanced forms of convolver handling:

Celestion SpeakerMix Pro - https://www.celestionplus.com/product/c ... ermix-pro/

Redwirez - https://redwirez.com/products/mixir3-ir-loader

Overloud SuperCabinet - https://www.overloud.com/products/supercabinet

Incognite Libra - https://www.stltones.com/products/stl-ignite-libra-1

With the first three you don’t have to worry about selecting a sampling rates, but with most you do have to select the appropriate one to suit your project, and in most cases they are not subject to real world issues like the potential for phase issues.

All the following mainstream software amp sims have some form of convolver:

Line 6 Helix Native

Postive Grid BIAS/FX

Overloud TH-U

IK Multimedia Amplitube

Scuffham S-Gear

Of course there are many others too!

The sampling process is usually done with high end selected amp examples, having several mic’s options in multiple positions. Some IR’s will be also sampled with multiple mic’s, in some cases with a back mic as well, but creative use and combining IR’s can usually achieve particular mic arrangements. In terms of mic positioning most will allow position setting across the cone and distance, but some will have just one or the other (Helix - distance only) (Speakermix Pro across the cone only), but in my experience it seems well compensated for and makes no noticeable difference!

What I can say is that using the right and cab(s) and mic(s) for you project correctly can make a big tonal difference!

[clivea]

Thanks Gary.
Very interesting and informative mate.

Clive