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IR Length

jon

Fractal Fanatic
Just a point to note for all those who are reading and may be wondering-there is NOTHING WRONG with the IRs just the way they are! Matter of fact I prefer the longer IRs, but it's a matter of taste.

All recorded music WILL have these reflections 'baked into' the recording, there is nothing 'wrong' with that, there is nothing 'WRONG' with the IRs - they sound different with truncated IRs and the removal of the reflections is just Cliff being Cliff in his perpetual quest for perfection!!

Certainly it was not something 99% of us even gave consideration to before (as most of the lack of understanding proves), so for those thinking there is something wrong, there's not, unless you wanna get granular about it.

Matter of fact one of the reasons the axe sounds the way it does is because of these ultra res IRs! The same ones with the reflections!

So turn a knob and if you like it, keep it that way, otherwise, just play and have fun! A couple milliseconds of reflection will not prevent you from enjoying the axe fx and is NOT a bad thing either!
 

Joe Bfstplk

Fractal Fanatic
I find myself looking for a nice ROOM IR to mix in around 10-15 dB below the close one most times. Might start playing with the cab block's 'room' feature more as an alternative, or just put in a super dry reverb to add early reflections easily to multi-amp presets.
 

CitizenKang

New Member
I experimented with reducing the IR length on one of my patches last night. Doing so seems to cut some top end and focus the overall sound more (more apparent with heavy overdrive), which I think sounds better at gig-level volumes. I've been searching for something that would easily let me focus my sound more aside from just EQ, so I'm glad I came across this trick!
 
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Joe Bfstplk

Fractal Fanatic
I experimented with reducing the IR length on one of my patches last night. Doing so seems to cut some top end and focus the overall sound more (more apparent with heavy overdrive), which I think sounds better at gig-level volumes.
This ^^^^ might be the key distinction - the shorter IRs sound better and more focused for dirt, and the longer ones are clearer, more detailed, and crisper for cleans....
 
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VidarAus

Inspired
I find myself looking for a nice ROOM IR to mix in around 10-15 dB below the close one most times. Might start playing with the cab block's 'room' feature more as an alternative, or just put in a super dry reverb to add early reflections easily to multi-amp presets.
I was too but found that the room feature in the cab block works brilliantly. Have been getting amazing results with different amounts and settings on that tab. Really good stuff.
 
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VidarAus

Inspired
I'm using this absolutely fantastic freeware (IR Workshop):

https://github.com/ValdemarOrn/IRWorkshop

The user guide:
https://github.com/ValdemarOrn/IRWorkshop/blob/master/Guide/Readme.md

It's complex and has a bit of a learning curve, but you can do a lot of deep tweaking with it. It's very option rich and I'm getting killer results from it. You can do so much with it to process/manipulate/generate IR's.

I export the IR as a .wav, load and convert it to .syx with CabLab. A bit of a process but I've got a fairly efficient workflow going with the various pieces.

One thing I'm finding is that I'm preferring the overall sound of a PEQ block before the AMP block to add girth/fatness around ~500Hz -> 600Hz vs baking that in post-AMP in the CAB block.

Again, I'm finding impressive results with it, and my time spent refining and playing with IR Workshop is paying off big time. I have astounding control over the generating process with the software, and I can't help but think generated IR's can be 'a thing' and maybe an evolution/addition to the all important IR component in cab modeling.
Haven’t run it, but read the user guide for IR Workshop. Seems to be a bit like Cablab. BUT it doesn’t mention any tools for generating synthetic IRs from scratch. Are you still starting with an IR capture, or how are you generating your synthetic IRs? Do you have any you could share for us to try out. Curious.
 

Stratoblaster

Fractal Fanatic
Haven’t run it, but read the user guide for IR Workshop. Seems to be a bit like Cablab. BUT it doesn’t mention any tools for generating synthetic IRs from scratch. Are you still starting with an IR capture, or how are you generating your synthetic IRs? Do you have any you could share for us to try out. Curious.
You can download sample cabs/presets (Synthetic_Cabinets.zip) here:

https://github.com/ValdemarOrn/IRWorkshop/releases

I started with the "Genius-Base.irw" in the "mono" folder and started my experimentation from there as it had a base character I could work with.

I've arrived at my latest iteration of cab based on that preset and that has evolved over a couple of months. I did put up some samples of my initial experiments but consider them 'depreciated' and my current IR is much better. It's been on my to-do list to upload my latest 'creation' and I'll try to get to that.

Starting from the "Genius-Base.irw" I adjusted the IR in the Spectrum stages to boost the low end as well as post-PEQ tweaks to add a bit more low end boost and pulled a lot of energy out from around 4KHz -> 7KHz with a broad PEQ cut. There were some more adjustments in the Spectrum stages that I can't recall at the moment but the above is more or less the gist of what I did. Experimentation is the key here...

It's still a bit 'crispy' in the high end and needs cuts in the CAB block to reduce that (but I did bake in a general rolloff in the EQ stage at ~8.5Khz though which I liked as a broad overall cut). I found that I liked to manually cut the high end in the CAB block vs baking a cut in the IR for flexibility; some tones/amps benefit from slightly more high end, some less, etc.

Similarly, as I mentioned, I fatten the entire IR with a pre-PEQ block vs baking that boost in; that works better for me (boost before the amp vs that mid boost post-amp).

I'm very happy with my current result; detailed, rich mids, clear highs, and, for whatever reason, the low end just jumps out and feels awesome without falling apart...banging on the low E string just 'barks' and sounds/feels way more natural then any NF IR I've ever tried and has an articulation/response/punch that I find incredibly satisfying. I feel like I've finally 'unlocked' a mystery with IR's these days.
 
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Stratoblaster

Fractal Fanatic
Are you still starting with an IR capture, or how are you generating your synthetic IRs?
Working with other user .wav IR's it does offer similar functionality in some ways to CabLab but does offer some more fine control. You can mix different .wav IR's, etc. as well. I've been playing with the sample length times and all sorts of things with mic IR captures.

Overall, a great tool and I really love it....am learning a lot about convolution and IR's with it. I'm completely rethinking my IR approach these days.
 
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VidarAus

Inspired
You can download sample cabs/presets (Synthetic_Cabinets.zip) here:

https://github.com/ValdemarOrn/IRWorkshop/releases

I started with the "Genius-Base.irw" in the "mono" folder and started my experimentation from there as it had a base character I could work with.

I've arrived at my latest iteration of cab based on that preset and that has evolved over a couple of months. I did put up some samples of my initial experiments but consider them 'depreciated' and my current IR is much better. It's been on my to-do list to upload my latest 'creation' and I'll try to get to that.

Starting from the "Genius-Base.irw" I adjusted the IR in the Spectrum stages to boost the low end as well as post-PEQ tweaks to add a bit more low end boost and pulled a lot of energy out from around 4KHz -> 7KHz with a broad PEQ cut. There were some more adjustments in the Spectrum stages that I can't recall at the moment but the above is more or less the gist of what I did. Experimentation is the key here...

It's still a bit 'crispy' in the high end and needs cuts in the CAB block to reduce that (but I did bake in a general rolloff in the EQ stage at ~8.5Khz though which I liked as a broad overall cut). I found that I liked to manually cut the high end in the CAB block vs baking a cut in the IR for flexibility; some tones/amps benefit from slightly more high end, some less, etc.

Similarly, as I mentioned, I fatten the entire IR with a pre-PEQ block vs baking that boost in; that works better for me (boost before the amp vs that mid boost post-amp).

I'm very happy with my current result; detailed, rich mids, clear highs, and, for whatever reason, the low end just jumps out and feels awesome without falling apart...banging on the low E string just 'barks' and sounds/feels way more natural then any NF IR I've ever tried and has an articulation/response/punch that I find incredibly satisfying. I feel like I've finally 'unlocked' a mystery with IR's these days.
Would love to try this IR you have created :)
 

York Audio

Power User
Vendor
What would an ir of an isolation box/cab sound like?
I think it would sound pretty congested. My band used to use iso cabs live and the tone had no life or energy to it. Once live cabs on stage were reintroduced, the tone came back. A cab needs room to breathe, and with an iso-box, the sound has nowhere to go and you get a lot of unwanted low end buildup.

I recently had a killer studio built, and my cab room was professionally treated by the same guy who did the treatment for Blackbird studios here in Nashville. My new IR’s are easily the best I’ve ever created, and it’s all due to the room and an improved capture technique. The room and treatment make a HUGE impact on the overall tonality of an IR if it’s shot accurately.

To your point earlier, every recording we’ve ever loved and the tones we’ve tried to replicate were all done with reflections baked into those sounds. I think it would be tough to tell in a mix if the IR’s were full length or truncated, especially since it’s common and encouraged practice to high pass guitars in order to clean up a mix.

And to Cliff’s point, I do notice a difference between full length and truncated IR’s while listening critically. I mainly hear the difference in the low end (in my personal IR’s). I also like MPT files because they give you control of the phase relationship you want or don’t want while blending IR’s as well as giving you the most information at the truncation point if you choose to shorten the impulse.

I’m sure there will always be a discussion between RAW and MPT files, but I’ve had Grammy award winning, Platinum selling producers, artists, boutique gear makers, and weekend warriors tell me they prefer the MPT versions. It’s better for their workflow and easier for them to create their own mixes...plus, they sound awesome.
 

Jarick

Experienced
I didn't follow the in-depth discussion, but I played around with the IR length in the cab block and the big thing I noticed was the shorter IR's have less low end. Maybe that is why Cliff is preferring to not have cuts?

With that in mind I swapped my usual 57+121 blend with low and high cuts to a wide-open 121 down to 512 samples and it sounds really nice. It's smoother overall (as a ribbon would be) but doesn't have quite as much low end build-up.
 

SeeD

Power User
I'm using this absolutely fantastic freeware (IR Workshop):

https://github.com/ValdemarOrn/IRWorkshop

The user guide:
https://github.com/ValdemarOrn/IRWorkshop/blob/master/Guide/Readme.md

It's complex and has a bit of a learning curve, but you can do a lot of deep tweaking with it. It's very option rich and I'm getting killer results from it. You can do so much with it to process/manipulate/generate IR's.

I export the IR as a .wav, load and convert it to .syx with CabLab. A bit of a process but I've got a fairly efficient workflow going with the various pieces.

One thing I'm finding is that I'm preferring the overall sound of a PEQ block before the AMP block to add girth/fatness around ~500Hz -> 600Hz vs baking that in post-AMP in the CAB block.

Again, I'm finding impressive results with it, and my time spent refining and playing with IR Workshop is paying off big time. I have astounding control over the generating process with the software, and I can't help but think generated IR's can be 'a thing' and maybe an evolution/addition to the all important IR component in cab modeling.
HI, would you mind sharing a test IR file ?
sounds like a cool thing your working on
 

VidarAus

Inspired
I think it would sound pretty congested. My band used to use iso cabs live and the tone had no life or energy to it. Once live cabs on stage were reintroduced, the tone came back. A cab needs room to breathe, and with an iso-box, the sound has nowhere to go and you get a lot of unwanted low end buildup.

I recently had a killer studio built, and my cab room was professionally treated by the same guy who did the treatment for Blackbird studios here in Nashville. My new IR’s are easily the best I’ve ever created, and it’s all due to the room and an improved capture technique. The room and treatment make a HUGE impact on the overall tonality of an IR if it’s shot accurately.

To your point earlier, every recording we’ve ever loved and the tones we’ve tried to replicate were all done with reflections baked into those sounds. I think it would be tough to tell in a mix if the IR’s were full length or truncated, especially since it’s common and encouraged practice to high pass guitars in order to clean up a mix.

And to Cliff’s point, I do notice a difference between full length and truncated IR’s while listening critically. I mainly hear the difference in the low end (in my personal IR’s). I also like MPT files because they give you control of the phase relationship you want or don’t want while blending IR’s as well as giving you the most information at the truncation point if you choose to shorten the impulse.

I’m sure there will always be a discussion between RAW and MPT files, but I’ve had Grammy award winning, Platinum selling producers, artists, boutique gear makers, and weekend warriors tell me they prefer the MPT versions. It’s better for their workflow and easier for them to create their own mixes...plus, they sound awesome.
Would you consider doing another Recto Standard (from the bi-polar Cab Pack) in your new studio? These IRs are still up there with the best I have ever used. Would be awesome to hear what else can be done in a new room with new techniques!
 

dr bonkers

Fractal Fanatic
Vendor
I find myself looking for a nice ROOM IR to mix in around 10-15 dB below the close one most times. Might start playing with the cab block's 'room' feature more as an alternative, or just put in a super dry reverb to add early reflections easily to multi-amp presets.
The room parameter is your friend in this case or a good reverb too.

Unless you are getting into convolution reverb IR files, the roomier IR files I experimented generating with tended to sound very demo like, even when mixed in low with more direct IR files.
 

deakle

Experienced
If it's one thing this thread has taught me, is that everyone has an opinion even if they have no idea, how it works, or even if they hear a difference or not.

Also that some of us definitely were sleeping in physics class.

On a serious note though, if you don't understand what an IR is or what it does or how it works or even physics in general, please do some reading and understanding on the topic, Cliff is giving us great info and insight here and I honestly think the thread is getting cluttered with misconceptions and erroneous statements. Please do some research first and let's have a more informed discussion please guys.

Also, turn a knob and see if it makes a difference to YOU....most people claim to not hear the difference between firmwares but are experts on a couple milliseconds of a reflection? Come on guys.....
Would you have any suggestions on good reading on this subject? I am very intrigued and would like to learn more. @FractalAudio Cliff, do you have any suggestions? I am very interested in this. It really has my Engineer mind yearning for more!
 
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