FF IRs: Capturing, using, blending, etc.

nikki-k

Experienced
With the recent discussion of FF vs/plus NF (Far Field versus/plus Near Field) IRs (not limited to Axe usage), I figured it might be a good idea to have a single thread with collected bits of wisdom, plus some objective bits as well. The most vital aspect of any IR is the method of creation/capture; I feel this is "beyond vital" with FF IRs. Scott has already provided some great tips, as well as some facts, so I will defer to him (IOW, this thread is being set out as "Scott Bait :D hehehe!). I have also spent time combing through threads in other places, and truly feel he has provided some great information and related experiences well there; I am hoping to see much of that brought here, with some added "Axe-Fx specifics" (especially with the IR Capture feature set in the Axe-Fx II).

How to create good/great FF IRs? 1x12 vs 2x12 vs 4x12? With an Axe-FX II? Do IRs require any editing to function well? Blending? Pitfalls to be aware of?

Scott? Pretty please?
 
Look for ground plane measurement and also a space big enough so that the first reflection arrives after 20ms.
 
I've been out for a while, I think I may have missed that NF/FF discussion, can you be so kind as to point me to it pleaaaaaase? *bats eyelashes* did a search but I think I read most of those already.....unless I missed something?
 
Look for ground plane measurement and also a space big enough so that the first reflection arrives after 20ms.

Does your .wav to .syx converter make your IR's minimum phase, or is that something that must be done at the deconvolution stage?

I noticed that a couple of Jay's newer FF IR's that he's posted in the past look very different in the phase tab in your utility as compared to other ones, and these IR's sounded really good...very cab like.
 
Does your .wav to .syx converter make your IR's minimum phase, or is that something that must be done at the deconvolution stage?

I noticed that a couple of Jay's newer FF IR's that he's posted in the past look very different in the phase tab in your utility as compared to other ones, and these IR's sounded really good...very cab like.

The minimum phase transform is not necessary in general. It destroys the phase response. So no my utility doesn't apply it.
 
This is a decent article on the setup for ground plane measurement.

ground plane measurement

I believe in Jay's old post about creating his 2x12 farfield he alludes to the 6db amplitude increase as described in the article above as the result of a ground plane measurement.

Richard
 
The minimum phase transform is not necessary in general. It destroys the phase response. So no my utility doesn't apply it.

IIRC Jay commented on TGP that the factory Axe versions of his far field IR's were subjected to some processing that he didn't care for too.

Richard
 
Here's my post-5.xx recommendations for live/recording. If you follow this, you may find that all the 'too bright!' and 'too dark!' sort of threads disappear. I cobbled this together from a few different posts all over the forums.

Amp/cab ONLY. No reverb, no effects, no PEQ, no EQ, no Global. Zip, nada, nothing. Just an amp/cab.

Start with your sound in the amp block. Take your cab block in the Axe-FX and make it stereo. Then pan them both center. Room settings to off. Speaker Cab Motor at 5.00 (noon). Proximity to taste. Make one speaker IR an OwnHammer that is a proper choice for your amp type (say the G65 OH) and *No Mic*; then the other make it a Jay Mitchell FF IR - I use the EV112 and G12-65 JM mainly and *No Mic*. In the amp block, then make the speaker drive 1.50.... and tweak in your Drive/Master Volume and then tone stack EQ on the amp block as you normally would till you like how it sounds. That's it.

IMHO, most all IR's you are using are all close mic'd and that's been a major flaw thus far in use with them... because that's how it's been done for decades. That's why mix engineers use so much EQ... and we have too with the Axe-FX (ie. blocking lows/highs after the cab, etc)..

Seriously, try this and let me know what you think.

Fender (or Fender Like tones):
OH 112 Boogafunk E12L/JM 112 EMI Open Back FF
Vox (or Vox like tones):
OH 112 Boogafunk Blue/JM EMI 112 Open Back FF
Marshall:
OH 412 SLM M75/JM 212 G12-65 FF
Higher Gain:
OH SLM G65 (*or OH V30, H75, Blue, or G65)/JM 212 G12-65 FFNote (repeated for emphasis): No mic. No room reverb from block. Speaker Motor Drive at 5.00 (noon). Both cabs panned center.

It'll sound good. Tweak from there to find your own flavors.
 
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Thanks!
I have never been a fan of using only NF mic techniques, despite that being the "norm" on recordings. In fact, when recording in a studio, I have sacrificed and compromised for years (prior to digital and *unlimited* numbers of tracks) in order to NOT rely upon a single (or even two, or three) close-mic tracks of each guitar part. When it comes to modelers, and especially the use of IRs, I have been at a loss concerning the use of (predominantly) NF IRs (et al). For live use, close-mic solutions were always a trade-off, and shy being afforded a "portable room" of some sort, or (gasp!) going with a DI solution, mandatory.

What Scott describes has become a HUGE solution for, what is for me at least, been quite a sore spot in "the great modeling compromise." I had tried both NF and FF previously, and had even experimented with blending various NF IRs in DAWquencers via the use of LePou's "LeCab" plugin (simple, brilliant, free! piece of goodness). Jay's FF IRs were the missing piece for me.

With that plateau attained, the next one in sight is to craft my own set. I have finally reduced my cab + speaker choices down to four cabs, and five speakers. To capture their "essence" to the greatest degree possible in the form of multiple IRs would (likely) be... sonic nirvana. For me. I have always loved blending, concocting. One of my 4x12s houses a disparate set of speakers; Dean Markley branded Celestion 85w plus some 200w jukebox speakers. Alone, each is awful. Together, they work... for me. The problem I face now is: how to best perform this "capturing"?

Oddly enough, I can read Jay's posts describing how to capture FF IRs, but I remain unsure about certain details without pictures, or better yet, video, showing the process. It is how my brain works. I could perform each step as described, but due to my neuronal demand and scrutiny of detail, doubt will infect the process for me until resolved. For instance: Jay states to place the microphone on the ground. Literally. Would placing the mic mere hairs above the ground secured to a mic stand not be better? What about cabinet placement? Orientation (say, for a 2x12)? What is the optimum dB for the *sweep*? When doing the off-axis, is the origin the center of the mic, the tip, or the end? Is z-plane orientation best left *flat*?

As subjective as recording techniques can be (with certain objective foundations), I see this recording journey requiring an initial objective foundation that needs to be experienced before any experimenting occurs (well, for me at least). I suppose it is also lazy, and possibly a bit "Gimme gimme! Now, now, now!" of me, to want these answers when I could invest hours.. scratch that, days, and possibly weeks... deriving these answers via research and application. Even with answers here, I will still perform the research as a means to greater understanding. A simple, "Here, do this to get that" has never sufficed for me, and never will. Why, what, and how remain forever perched.
 
Thanks!
I have never been a fan of using only NF mic techniques, despite that being the "norm" on recordings. In fact, when recording in a studio, I have sacrificed and compromised for years (prior to digital and *unlimited* numbers of tracks) in order to NOT rely upon a single (or even two, or three) close-mic tracks of each guitar part. When it comes to modelers, and especially the use of IRs, I have been at a loss concerning the use of (predominantly) NF IRs (et al). For live use, close-mic solutions were always a trade-off, and shy being afforded a "portable room" of some sort, or (gasp!) going with a DI solution, mandatory.

What Scott describes has become a HUGE solution for, what is for me at least, been quite a sore spot in "the great modeling compromise." I had tried both NF and FF previously, and had even experimented with blending various NF IRs in DAWquencers via the use of LePou's "LeCab" plugin (simple, brilliant, free! piece of goodness). Jay's FF IRs were the missing piece for me.

With that plateau attained, the next one in sight is to craft my own set. I have finally reduced my cab + speaker choices down to four cabs, and five speakers. To capture their "essence" to the greatest degree possible in the form of multiple IRs would (likely) be... sonic nirvana. For me. I have always loved blending, concocting. One of my 4x12s houses a disparate set of speakers; Dean Markley branded Celestion 85w plus some 200w jukebox speakers. Alone, each is awful. Together, they work... for me. The problem I face now is: how to best perform this "capturing"?

Oddly enough, I can read Jay's posts describing how to capture FF IRs, but I remain unsure about certain details without pictures, or better yet, video, showing the process. It is how my brain works. I could perform each step as described, but due to my neuronal demand and scrutiny of detail, doubt will infect the process for me until resolved. For instance: Jay states to place the microphone on the ground. Literally. Would placing the mic mere hairs above the ground secured to a mic stand not be better? What about cabinet placement? Orientation (say, for a 2x12)? What is the optimum dB for the *sweep*? When doing the off-axis, is the origin the center of the mic, the tip, or the end? Is z-plane orientation best left *flat*?

As subjective as recording techniques can be (with certain objective foundations), I see this recording journey requiring an initial objective foundation that needs to be experienced before any experimenting occurs (well, for me at least). I suppose it is also lazy, and possibly a bit "Gimme gimme! Now, now, now!" of me, to want these answers when I could invest hours.. scratch that, days, and possibly weeks... deriving these answers via research and application. Even with answers here, I will still perform the research as a means to greater understanding. A simple, "Here, do this to get that" has never sufficed for me, and never will. Why, what, and how remain forever perched.

I would think that with Jay mentioning that at some point this year he will be selling IR's... that he'd be less than forthcoming at this point (or moving forward) in instructing others how to do FF correctly according to his standards/procedures. I have zero expertise in the capturing of IR's; I'm a slave to what is available for purchase or shared by others. I do not have the time or equipment nor desire to even attempt it.

That said, please note that I do NOT speak for Jay nor pretend to. But, you can find him on TGP and send him a PM there. Never hurts to try.

My only word of advice for you is to trust your own ears. All the science and expertise in the world can't make me play a better barre-A chord. If it sounds good, it is good. Nothing - NOTHING - else matters.
 
I tried Scott's method on several of my patches over the last few days and really like the results. It completely makes sense based on my experience of real amps. I like Fender amps a lot and have gigged a lot with BF Fenders or similar amps. Right in front of the speaker it sounds horrible. The fizz and brightness people have recently noted in the Axe is what I hear from my Fenders. When you back off the cone, you hear a blend of sound from the front, the back and some of that fizz comes through as cut, but it's much reduced and no longer an irritant.

Scott's method of blending helps chill out the high end harshness with the FF IR which will not have the fizz of a NF IR. Blending gives the ability to get the crispness back without it sounding harsh and brittle like it does with only NF. I'm also using RCF's like Scott (10's though) and they are really clear. Without this far-field blend, my ears were getting toasted by the high end a bit. Now the sound is much more user friendly.

This is a great tip and I look forward to people developing more FF IR's. I'm in Scott's camp of too many things to do to want to do it myself. My studio is also too small to escape room effect with the 20ms rule Adam notes. I look forward to taking full advantage of the hard work others do though whether for fun or profit;-)
 
Thanks Scott!
I will seriously consider writing to him. Honestly, I feel I should spend a considerable amount of energy acquiring knowledge and experience before doing so. Not sure why exactly. Perhaps so as to not feel I am wasting his time with *simple* or (perhaps seemingly) trivial questions. As far as him releasing IRs.. cool! Oddly enough though, with your (Scott's) blending idea, my single goal.. obsessively so.. is capturing "my world."

Now I need to get a schedule from my neighbors of when they will NOT be at home :D I would be perfectly content experimenting for many hours at a time; my sole concern is for making others... unhappy. And find a good deconvolving app.
 
Voxengo Deconvolver is what most people are using, and the locked (free) version is fully functional except that it will only do three conversions before you have to restart the program.

I've got some notes I collected from Jay's posts that I'll dig out as soon as I get a chance.
 
Hey Scott - I tried your FF blend method and it really works great! The sound is much more natural to my ears - I only wish I had a few more of these FF IRs to experiment with! :) This really has me thinking that the Cab is the key to realistic amp sounds - maybe this is where the Kemper shines?
 
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I like FF IRs best on their own. If you have a good FRFR system, it actually sounds like you have a guitar cab in front of you.
 
Hey Scott - I tried your FF blend method and it really works great! The sound is much more natural to my ears - I only wish I had a few more of these FF IRs to experiment with! :) This really has me thinking that the Cab is the key to realistic amp sounds - maybe this is where the Kemper shines?

Great - and I agree. I imagine a day when there are a range of quality FF IR's available ala Jay's method of capturing them but with a fuller range of speakers.

I have held out from the first day that the biggest component of your tone running FRFR in the modeling chain is the speaker IR. I've never doubted it.

I think this is where the Kemper doesn't shine at all. It cannot use FF IR's, unless they are captured that way. The amount of expertise needed to do that as per Jay's guidelines is beyond the scope and possibility of the normal owner and even the higher end engineer in a recording studio. To date, from my understanding, there isn't many let alone one FF attempt in the Kemper by anyone with Jay's methods and expertise; and the ability to mix different spacing and speakers isn't - ala mixing IR's -- at this point - even possible unless captured that way. No one is; they are all right up on the grille... which isn't natural. So, IMHO, that's a negative with the Kemper, not any sort of advantage at all.

Instead, with the Kemper it is my personal theory that the Kemper, during the 'refine' process is simply doing a match EQ. That, at this point, is only possible with the Axe-FX with use of a DAW. If - and this is speculation by me only!!!! - the Axe-FX gains some sort of Match EQ with Cliff's expertise in doing so from just the Axe-FX.... look out. With the depth of what the Axe-FX already offers down to component level modeling; added to the power of Match EQ *and* use of FF IR's... well, draw your own conclusions. The future is bright; no matter what gear you use. Me? I'll stick to the black box. ;) :D
 
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Scott (and everybody else) - Please don't get me wrong, I believe the AFXll has a *brilliant* future ahead because of it's unmatched digital processing potential as well as Cliff's *serious* programming prowess. I just know there must be something the Kemper fans are hearing that is different and possibly more natural-sounding in the final response. The AFXll is a *Keeper*!
 
Scott (and everybody else) - Please don't get me wrong, I believe the AFXll has a *brilliant* future ahead because of it's unmatched digital processing potential as well as Cliff's *serious* programming prowess. I just know there must be something the Kemper fans are hearing that is different and possibly more natural-sounding in the final response. The AFXll is a *Keeper*!

I'd say again that if you use a Match EQ with your DAW and drop that in your Axe-FX the playing field vastly changes.

And I'll also say that if you really break down the clips from either the Axe-FX or Kemper done with only NF IR's... well, they both exhibit the same issues though the Kemper - with it's 'refinement' (aka Match EQ) - just has the advantage of a match EQ built in.
 
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