Cabinet Impulse Response (IR) Plugins shootout!


Count Blastula
Nov 20, 2009
Hi there! I'm a firm believer cabinet is the most important link in the chain regarding guitar tones (apart from hands of course), so I recently did a comparison between different softwares that enable Impulse Response loading, to check if they do have sonic differences and, if yes, which one behaves better with the same impulse.

DISCLAIMER: this is not a "good tone" sample test, it's just to show how sonically different these softwares/plugins are between each other. In fact, I just tweaked a decent tone in 5 minutes with my Axe II and recorded a first take boring riff with the cab block bypassed.

Gear used in this shootout:

Amp: Axe-Fx II (TS808 drive->5153 amp block)
Guitar: Carvin CS4 Drop D tuning
Impulse: Telos IR#4 from Redline4, download here:

Softwares compared:

Fractal Audio Axe-Fx II (UltraRes IR quality): LOADER COMPARISON/Axe Fx II.wav


Redwirez MixIR 2: LOADER COMPARISON/MixIR 2.wav

Ignite Amps NadIR (Extreme quality setting): LOADER COMPARISON/NadIR.wav

TSE X50 v2 (8x oversampling, highest quality): LOADER COMPARISON/X50 v2.wav

Also here's a zip file with all the wavs included: LOADER COMPARISON/CAB LOADER

Wav files are much better quality, but if you want something quick here's Soundcloud links:





X50 V2

Personal opinion:

Axe-Fx II sounds the best along with X50 v2 - both very good, punchy, musical and transparent representations of the impulse. Unfortunately I don't own X50 v2 but one of my students does, so he helped me out with the comparison.
NadIR is 95% there, only a hair darker with highs rolled off a liiiittle bit.
MixIR 2 seems to add more aggressive upper mids which I personally don't like, and LeCab is the worst, adding lots of noisy highs/presence.

Differences in the end are very subtle, all these softwares can work with no issue within a mix - also with some Match EQ applied the slight differences would disappear. Although I know from now on that if I need to use something out of my Axe-Fx II, it will most likely be X50 v2 or NadIR.

Hope you enjoyed this shootout! If you want to hear any other free IR loader plugins added to this comparison, feel free to suggest :)
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to do the software justice, did you make sure the wav lenght is all the same on those clips? because some cut the wave shorter. x50 v2 doesn't count either, because it does have "space/dynamics adding technology" - not quite sure how it's called. did you turn that off?
to do the software justice, did you make sure the wav lenght is all the same on those clips? because some cut the wave shorter. x50 v2 doesn't count either, because it does have "space/dynamics adding technology" - not quite sure how it's called. did you turn that off?

I made sure my student turned all the X50 additional options off, yes. Did that via skype and screensharing so I know for sure those were off.

I made sure all of them were the same length and same exact loudness. If some of them seem a hair louder or quieter, it's just because they sound a bit different :)
The difference is almost imperceptible. I only noticed lecab high frequencies and probably because you said it!lol The rest is the same, and in a mix no one can figure it.
Super sick experiment man, glad you used my impulse. Kinda funny that I use leCab1 to monitor while I create, shape and test my impulses. Guess I could have a go at trying some other IR loaders, seeing that there's (not gignatic but still) a sonic difference between them.
I think that Lecab and X50v2 sound the bes, there so many presense in them,
the worst is Mixir 2 I think, there is almost no highes, copare to others. Thanks for research, very interesting ^)
To my ears, it's like LeCab is by default not 100% wet, therefore still leaving a bit of the original cab-less amp signal, which results in higher frequency noise.
It's not a wet/dry issue, the problem is due to the supported IR length. If the IR is being cut too short, the accuracy decreases.
He pointed that out on his blog:

I don't know what max IR length LeCab2 does support, but looking at the graph on his blog, my guess are 256 or 512 samples at 44100Hz.
I can't speak for the other devs as I don't know the specs of their convolvers (I think the TSE one doesn't have any limitation, but I can be wrong), but NadIR goes up to 8192 samples at 44100Hz (that "Extreme" quality setting you're using).

Hope it helps
RE: Wild Hades on sample length.

Here's a post from Cliff at Fractal regarding sample length. I don't own an AxeFX, nor am I promoting it, however it's a good technical discussion on the impact of sample length and important reading for those wishing to understand the factors that affect their amp sim/cab IR tone.

Also, good thread. Not nearly enough discussions like this on ASF to really understand the tools that we use.
Ok I must say that I did some tests myself and there is a difference. A difference in clarity essentially, at first even if it doesnt seem quite significative, it would be bigger, if you have quadtracked guitars. Because, a bit less clarity in one track might not be for concern but multiplied by 4, it´s something that will affect the final product and perception and would not be in a good way.

I didnt heard much difference in OP tracks but probably because I heard the tracks from soundcloud.