I think I can justifiably say that I'm not normally a slouch with hi-tech gear, but I've been struggling to really nail the sound I wanted with my Helix LT. Too many options all at once, steep learning curve, real life intruding. Last weekend I finally got it together and I thought I'd share at the expense of looking a bit of a fool, because it was Max that fixed it.
I have been using IRs with my Helix because of resource usage rather than for any dislike of the Helix cabs - although I couldn’t really get the sound I wanted out of those either. I like to have an AC30 =and= a JCM800 in my patches and there isn’t quite enough resource in the helix to get both native cabinet emulations loaded together with all my other favourite effects. Contrast: you can have a single IR block and switch cabinet IRs with a snapshot as you mute the amp you don't need. But the IRs I was using weren’t cutting mustard and I didn’t understand why.
For me the difficulty had been in understanding how to mic up guitar cabs. No scrap that. My difficulty had been understanding, that with everything else going on in the patch, (virtually) miking up the cabinet was where I was going wrong.
I don’t know how we got there but at some point towards the end of a long conversation that started with Max berating my guitar sound, I asked him ‘how would you go about getting a good sound in the real world’ and he said something like ‘I’d get a SM57 and I’d point it to the edge of the dust cap off axis and then I’d move it away from the speaker until I got the sound I wanted. Usually half and inch or so. Everyone does it that way’.
Aha! Thought I. Surely amongst the vast array of free IRs I’ve acquired from the internet there must be one that fits that description. There were none. Neither were there any professing a R121 2” from cap edge. Or a U87 2” from cap edge. Or Sennheiser 4x1s 0.5' from cap edge. There =may= be several that were miked up in that way, but none had the metadata so I could find them. Or maybe they don't exist in (legal) free archives because these are the money, and no-one gives them away. Probably both.
(I type that like I knew what a cap edge actually was and its significance in guitar cabinet recording before last weekend. I didn’t).
At this point I decided to throw caution to the wind and actually fork out on a set of IRs. I’d heard that Shuffham - love the plugin - used Redwirez so I thought I'd try those first. I found a modern Marshall 1960, noticed that the component files were named exactly as Max specified, spent the princely sum of $9 and copied the appropriate ‘0.5” SM57 cap edge off axis’ file into my Helix.
Bingo. In one. Even I could tell that it had worked.
I sent Max a wav of a riff: ‘Spot on, I just needed to roll off a bit of low end. Should have bought the Orange cab though - they sound better'. Well you can't win them all!

Anyway then I found this on the redwirez website https://www.redwirez.com/ir/DialingInYourTone.pdf. ‘I’ll just load all their recommended IRs and see how that goes’ I thought. Every IR mentioned here sounded as expected - as near as damn it like my beloved JMP1/GMajor/EL84 20-20 rig plugged into a 1960 cab with that mic: the Royer indeed had air; the 57 aggression; U87 was good but not me; do you think I could treat myself to a 421 for Christmas? … I could even hear through the sound to immediately realise I needed to pull back the mids on the amp model.
—
So TIL.
Without denigrating any other suppliers, I think Redwirez are ace. If not for the IRs themselves then for the way they are filed/curated, making knowledge from the real world applicable in the virtual.
My Helix is more than just an FX box with amp modelling: its nothing less than a virtual studio for guitars. I need to learn a lot more about how to engineer guitars to get the most out of it.
Moreover I didn't have a concrete idea of what a good miked up guitar cab sounds like - which is ultimately why I was struggling. My previous modellers simply didn't have the options - the VG99 has some filters that vaguely sound like the mics in question (does one say SM57, yes - job done), my JMP1 has two balanced jack sockets with 'speaker emulation' proudly written on the casing (to be fair they work quite well in a mix). Go back any further and I was paying an engineer. Most of the people around here are sniggering having miked up thousands of guitar cabs - but if you are struggling and lack experience (I’ve spent the last year delving into HRM on my VG99, ultimately making a pretty convincing Vox Humana preset amongst other sounds) then $9 for some handy reference points on your fave cab to load into your AxeFX or Helix is astonishingly good value for money.
And finally, thanks, Max! You are a star!