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Why I won't be using the cab block for recording any more

SarasotaSwing

Experienced
Well this is embarrassing.

I refused to believe that there could be that much difference as I've extensively tested UltraRes in the past. So I just ran some tests and, sure enough, there was a difference. Turns out UltraRes has been broke since Version 16.03. We made some code optimizations and moved some stuff between stack and heap and missed a variable.

Sooooo... Version 18.07 will coming soon.
It's called human error for a reason. I'm pretty sure that even Steven Hawking has had some "ooops" moments as well. ;-)
 

FractalAudio

Administrator
Fractal Audio Systems
Moderator
Well then I sure hope that I can re-title this thread "Why I won't use the cab block until FW 18.07 is released" - LOL.

Big of you to admit it man. And glad I'm not insane and just hearing nonsense bullshit. :encouragement:

But in all seriousness, unless Kevin of OwnHammer hadn't harangued me into trying the longer IRs, we'd all be just derpin' around happy as could be. So I want to thank Kevin for getting me interested in this so I could bring my findings to the forum. Onward to greatness with the Axe!
I'm a huge advocate of longer IRs. In fact I think I was the first to advocate it despite all the naysayers. I pushed OwnHammer (and others) to increase their IR lengths and they were the only ones who acted on that advice (so far, maybe the other guys will start to follow suit). UltraRes was born out of the desire for longer IRs.

For recording you don't need to use the cab block in the Axe-Fx though. Record the raw amp sound and then "re-cab" it later. This way you can try different cabs. Cab-Lab is great for this. Cab-Lab does not do UltraRes processing. It creates UltraRes files for the Axe-Fx but it does all processing at the full IR length up to 8K samples. You can use other convolution plug-ins as well.

The reason for UltraRes is that long IRs have several drawbacks:
1. They require lots of storage space. Not an issue on a computer but on a hardware product that means expensive non-volatile memory.
2. They require lots of processing power if you don't want any latency. On a computer it doesn't matter since latency is a non-factor if you are processing prerecorded tracks. On a hardware product we must have zero latency.

So UltraRes was devised as a way to exploit the statistics of the data to give the benefits of longer IRs without the usual hardware drawbacks.
 

mongey

Inspired
Well this is embarrassing.

I refused to believe that there could be that much difference as I've extensively tested UltraRes in the past. So I just ran some tests and, sure enough, there was a difference. Turns out UltraRes has been broke since Version 16.03. We made some code optimizations and moved some stuff between stack and heap and missed a variable.

Sooooo... Version 18.07 will coming soon.

lol. there ya go .

I think I got my xl with mid 16's FW so it has never worked proewplery while I've owned it .Interested to see if I notice a big change

Was going to go to 18.06 today after work so guess i'll hold off
 

mwd

Power User
...For recording you don't need to use the cab block in the Axe-Fx though. Record the raw amp sound and then "re-cab" it later. This way you can try different cabs...
Thank you for this. About to pull my hair out trying to figure out what you guys are talking about. This kinda' helps.
 
Cliff you misunderstand me. I completely realize the limitations of the Axe-fx cab system, and I totally get why it is. What I was pointing out was that it was Kevin who recently asked me if I ever tried longer IRs, to which I said UR was fine. Because well... I'd never tried 500 ms long IRs in the DAW before. And when I did finally give in I realized there was a pretty noticeable difference and started testing it. That was about a week ago. I wanted to make sure I wasn't totally full of piss before I came on here and brought it up. Were it not for Kevin, we would have never had this discussion at all.

But if you're saying UR should sound just like a long IR, and I could skip a step in the workflow, that's probably what I'll end up doing. But if you think long IRs will beat them out I will continue to rely on them this way. Of course, I will be testing the system as soon as it's out. :D
 

FractalAudio

Administrator
Fractal Audio Systems
Moderator
But if you're saying UR should sound just like a long IR, and I could skip a step in the workflow, that's probably what I'll end up doing. But if you think long IRs will beat them out I will continue to rely on them this way. Of course, I will be testing the system as soon as it's out. :D
It should sound very similar. Mathematically it's not exactly the same. From a human auditory perspective it's virtually identical though. The only way to know is to do a comparison with the fixed firmware. In my tests I cannot hear a difference and I clearly heard a difference in the clips you posted earlier (the first clip was the Axe-Fx btw, I could hear the error in the bass response).

In my tests I've found that 8K samples (170 ms) is more than enough. I think 500 ms (24K samples) is overkill and if an IR has significant energy out that far then it has too much room in it. The speaker and cab itself are never more than 100 ms, usually much less. Anything beyond that is the room. I personally don't like IRs with lots of room in them. A little bit of early reflections are nice and make things sound less direct but too much room makes the sound get lost in the mix.
 

chris

Legend!
So is this in the UltraRes creation process? Or using any UltraRes can in general? I'm not too familiar with this stuff :)
can anyone comment on this question please? i'm assuming now it's about the UltraRes creation process using the Axe?

18.07 tonight? :D
aww man, why even say that... let him do the work he needs to do and release it when he's done. i'm sure you're only 1/2 joking... but still.

this forum is full of people asking him to do things faster, better, easier, etc. and though 98% of it might be mostly joking, it all adds up and puts pressure on him to actually meet these ridiculous requests. and then he DOES meet the ridiculous requests...

cliff. man. take a break yo. please. what can we do to help with that?
 

Hellbat

Fractal Fanatic
can anyone comment on this question please? i'm assuming now it's about the UltraRes creation process using the Axe?
If I understand it correctly the error is causing the hardware to improperly 'render' the IR. The IR file itself is fine, but it isn't being applied to the signal correctly. However I am not the sharpest stick, so that is quite possibly explicitly wrong.
 

Moke

Fractal Fanatic
Vendor
Wow, what a thread...........I can't wait for the movie!....lol

Seriously..........Nice catch!

After this Saturday I will have no live shows for 3 weekends in a row. Finally get to upgrade from 17.04 to FW 18 (18.07 so far)
 

AndyOrr

Inspired
This has been interesting. There are three impressive facts about this thread:

1. The OP and others identified a real problem with the cab IR's that many others missed.

2. FAS was skeptical but listened and not only concurred, they fixed it in under 1/2 hour.

3. Someone actually knows how to use Space Designer in Logic!
 

dbun

Experienced
Well this is embarrassing.

I refused to believe that there could be that much difference as I've extensively tested UltraRes in the past. So I just ran some tests and, sure enough, there was a difference. Turns out UltraRes has been broke since Version 16.03. We made some code optimizations and moved some stuff between stack and heap and missed a variable.
This is great to see - a company owning up to an error and being upfront about everything.
This earns more respect than going quiet on an issue and trying to sweep it under the carpet and fix it in the background.

Well done.

Also, thanks to the OP for pushing this issue.

Can't wait to get back and try out this new FW. This "broken" box I've been playing has been giving me the best tones I've every had, so I can't wait to hear what it was supposed to sound like!
 
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