Another Axe/Kemper Comparison Clip

[Jay Mitchell]

Originally Posted by OverHTheHill

Same answer that you get when you ask about a cabinet "IR", shouldn't the IR be generated throught the actual amp that was modeled.

No. If you want the sound of a cab to use with models of different amplifiers, you do not want any influence from an amplifier in the impulse response of the cab.

The answer would be something like the "speaker response is so linear" that a snap shot is more than good enough.

No. You would not understand a complete, accurate explanation of this matter, but that does not invalidate such an answer.

I think that generating an impulse using other gear than the actual amp being modeled is a compromise

You're allowed to think whatever you like. In this case, what you think is incorrect.

This actually makes me believe that the Kemper has an advantage in realism in that aspect, it actually generate the cabinet at the same time from the amp it's profiling,

No. The only result it can possibly generate - the limitations on this are due to physical and mathematical principles that cannot be violated - is a profile consisting of the combined response of amp, cab, and mic. Assertions that the response of the cab can be accurately separated from this combination are false, regardless of who is making them. If you want a representation of a cab by itself - and that is definitely what you want if you intend to use that representation with models of different amps - then you must acquire that representation from only the cab. Adding the colorations and distortions of a guitar amp can only degrade the accuracy of the speaker profile.

The proof of the limitation of Impulse respones is that different vendors IR of the same cab with same mic and same distance generate different results.

Your premise - the assumption that different vendors actually acquire IRs under identical circumstances - is incorrect. I can tell you from many years of professional experience in this field that, when conditions are identical, the results will likewise be identical. Controlling the conditions of acquisition of IRs is highly nontrivial. I see no evidence that the present vendors of same are particularly well-versed in this area.

[OverHTheHill]

You just proved my point, why should vendors acquire "IR" in different methods or as you say "under identical circumstances” if someone can scientifically proof that a specific method will generate identical results to the CAB.

I'm sure you have experience and I respect that very much, but until a standard is adopted or accepted to what conditions or under what “identical circumstances" an IR is considered a faithful representation, it seems that you’re agreeing with me that the IRs as available today are not accurate but rather imposed on and refined by whatever process the vendor finds suitable, i.e. IRs currently suffer in being accurate representation as they're being offered and sold mainly for their presumed accuracy.

Originally Posted by Jay Mitchell

Your premise - the assumption that different vendors actually acquire IRs under identical circumstances - is incorrect. I can tell you from many years of professional experience in this field that, when conditions are identical, the results will likewise be identical. Controlling the conditions of acquisition of IRs is highly nontrivial. I see no evidence that the present vendors of same are particularly well-versed in this area.

[OverHTheHill]

There might be an answer to this when Kemper Profiling amp comes out I guess because it's acquiring the speaker information from the actual amp it's attempting to model, that's if they ever release it. Maybe the dark cloud of bad impulse responses will be be lifted (or the blanket)

Originally Posted by OverHTheHill

I think that generating an impulse using other gear than the actual amp being modeled is a compromise

Originally Posted by Jay Mitchell

You're allowed to think whatever you like. In this case, what you think is incorrect.

[m~Dan]

Originally Posted by Jay Mitchell

No. The only result it can possibly generate - the limitations on this are due to physical and mathematical principles that cannot be violated - is a profile consisting of the combined response of amp, cab, and mic.

Check that video. I think it's amazing!

[guitarnet70]

Well, look I'm not really looking to get fighting again, my opinion is that a compressed mp3 file is just a vague indication that cannot substitute a first hand experience, it cannot transmit the "feel" and the iteration while you're playing. Maybe I was tired and I've expressed myself a bit too directly, no offense intended, I still believe that listening to a demo (even in first person) cannot substitute the gut feel that you get when playing yourself. Back to the Kemper: the refining process just compare the source to the copy, the guitar has no influence being the profiling part made without it. Changing guitar require obviously some adjustment tha can be easy made and saved in a separate "rig" (patch).

[m~Dan]

Originally Posted by guitarnet70

the refining process just compare the source to the copy, the guitar has no influence being the profiling part made without it.

That's 100% correct. I used a sine-generator (on my iPhone ) to see how refining works without a guitar: It worked very well!

[OverHTheHill]

That was very cool. Sorry I don't understand German, but did you say that was Blackmore ENGL model. You're tempting me.

Originally Posted by m~Dan

Check that video. I think it's amazing!

[Jay Mitchell]

Originally Posted by OverHTheHill

until a standard is adopted or accepted to what conditions or under what “identical circumstances" an IR is considered a faithful representation,

It is possible to understand how to acquire an IR that is a "faithful representation" of the device being tested in the absence of a "standard" for same. There are those of us who have devoted decades of our lives to acquiring such insights. This level of understanding is not widespread, and it most definitely cannot be conveyed to others in posts on an online forum.

it seems that you’re agreeing with me that the IRs as available today are not accurate

Not so. They could be perfectly accurate, which simply means that they faithfully capture the response of the system being tested under the specific test conditions. If those test conditions are not a good representation of real-world use of a cab, then IRs acquired under those conditions will fail to create the sound a player would hear when playing through that cab.

When close-mic'ing a guitar speaker, mic position changes as small as a few millimeters will profoundly alter the sound. If you compare two IRs that were taken on the same speaker with the same mic, but with a difference in mic position of, say, 10mm, they will often sound quite different. Which is more "accurate?" The answer is that both may be accurate. Of much greater relevance is the fact that neither will produce the sound you would hear while playing through the cab.

[Gasp100]

Originally Posted by stratzrus

I really hope that people like that are few and far between. I get the impression that most people here, and particularly those considering an Axe FX II or KPA, are serious about gear and are more concerned with how it's going to work for them than simply needing to have the latest and greatest.

I can't imagine that people buying gear are more concerned with their status than the utility of the amp, but maybe you're right.

Agreed... I hope DADA's post wasn't geared towards me using the term "acquisition" to justify my purchase of the II. I weigh in on a lot of these discussions because I have first hand experience using all of this gear (as much as a hard working, 41 year old, father of 3 young kids has time to do).
Look, the proof is out there... virtually (no pun intended) the entire crop of new modeling gear is completely useable and sounds very good. From the Z to A (literally, Zoom G3 to AxeFX) I have tried it all, it all "works" and I can get it all to sound really good, find inspiration using the tools and most importantly, having fun.
I've heard enough from the KPA clips (and end user experience) to determine it is top shelf. It is clearly a direct competitor to the AxeFX II in terms of core amp tones, functionality, build quality / tech and of course PRICE.
I don't even know what we are discussing anymore on this forum... the tech is out there and provides the ability to get kick ass tones. It seems like at this point we are picking apart posts/threads vs. talking about anything of substance anymore. I feel like I'm on some type of political discussion forum vs. a gear forum.
Peace.

[OverHTheHill]

Thank you for that, but the bottom line is that most guitar player aren't really concerned with how it works anyway as long as it sounds good. IRs sound pretty close to recorded amps and that's good enough for me. If kemper is going to capture the Cab, I don't care what he calls it. If he calls CAB profile or whatever as long as it works with a guitar, I doubt that most guitar players are going to be concerned whether it's an IR or PR.

I would pick a different name other than IR as IRs have exhausted their full potential by now and guitarist are probably ready to try something else since it seems the making of IRs is so secretive but doesn’t generate consistent results anyway. It’s reminiscent of when Ed Van halen first started finger tapping and when he first used to play live he would turn his back to hide what he was doing.

Originally Posted by Jay Mitchell

It is possible to understand how to acquire an IR that is a "faithful representation" of the device being tested in the absence of a "standard" for same. There are those of us who have devoted decades of our lives to acquiring such insights. This level of understanding is not widespread, and it most definitely cannot be conveyed to others in posts on an online forum.

Originally Posted by Jay Mitchell

Not so. They could be perfectly accurate, which simply means that they faithfully capture the response of the system being tested under the specific test conditions. If those test conditions are not a good representation of real-world use of a cab, then IRs acquired under those conditions will fail to create the sound a player would hear when playing through that cab.

When close-mic'ing a guitar speaker, mic position changes as small as a few millimeters will profoundly alter the sound. If you compare two IRs that were taken on the same speaker with the same mic, but with a difference in mic position of, say, 10mm, they will often sound quite different. Which is more "accurate?" The answer is that both may be accurate. Of much greater relevance is the fact that neither will produce the sound you would hear while playing through the cab.

[Gasp100]

Originally Posted by OverHTheHill

There might be an answer to this when Kemper Profiling amp comes out I guess because it's acquiring the speaker information from the actual amp it's attempting to model, that's if they ever release it. Maybe the dark cloud of bad impulse responses will be be lifted (or the blanket)

And yet one of the selling points of the KPA is that you can reliably decouple the original cab from the profile and substitute another one, completely different with no issues.
More digital alchemy?
I agree with you, the IR capture process will never be able to completely and accurately capture just the sound of a cab with absolutely no coloration from mic or amplifier sending the source signal.
But, I have found that I can usually find an IR that is close enough for me in my patches
If you have a cab but don't play anything through it does it make a sound?

[Eric Thomas]

Originally Posted by Gasp100

I don't even know what we are discussing anymore on this forum... the tech is out there and provides the ability to get kick ass tones. It seems like at this point we are picking apart posts/threads vs. talking about anything of substance anymore. I feel like I'm on some type of political discussion forum vs. a gear forum.
Peace.

I can relate to this. I am about to give up on the Gear Page for this very reason.

Parts of this thread gave me reason to believe that we can discuss gear intelligently with the intent of learning from each other, and parts of this thread remind me why I've about had it with the Gear Page. I think I'm going to wait until 6 months AFTER the KPA is released before I read another KPA thread.

[OverHTheHill]

I think IRs are great, but just a little cumbersome to go throught alot of them. I usually find something very quick from the 12 or more more that I usally use, but I thought it was crazy when a friend of mine was showing me his Red Wirez collection I believe. He coudn't find an IR so he did some sort of search and there was if I remember correctly about 50,000 (that's thousands) if not doulbe or triple that.
He explained that at each bit rate and various sampling rate there's a set of the same impulses and proceeded to explain the methodology of not having to go through all of them. He seems to think they're worth every penny he paid for them and I don't doubt that, but for 50 thousands files or more! Is this possible?I don't have the patience for that sorry.

life is too short to even copy that much files on a hard drive. never mind going through less than 1% of such numbers.

Originally Posted by Gasp100

And yet one of the selling points of the KPA is that you can reliably decouple the original cab from the profile and substitute another one, completely different with no issues.
More digital alchemy?
I agree with you, the IR capture process will never be able to completely and accurately capture just the sound of a cab with absolutely no coloration from mic or amplifier sending the source signal.
But, I have found that I can usually find an IR that is close enough for me in my patches
If you have a cab but don't play anything through it does it make a sound?

[Jay Mitchell]

Originally Posted by OverHTheHill

I would pick a different name other than IR as IRs have exhausted their full potential by now

You could not be more wrong. IRs have huge, untapped potential. The technology is not the limitation, the people using the technology (IOW, the people who are acquiring IRs) are.

[Jay Mitchell]

Originally Posted by OverHTheHill

I think IRs are great, but just a little cumbersome to go throught alot of them.

So lemme get this straight: you think it's more cumbersome to go through "a lot" of IRs than similar number of physical cabs/mics/mic positions?