Ultrares IRs?

Colorado Axeman said:
Depending on how much they are truncated, the FM3 may not sound exactly the same as the Axe-Fx III. Longer IR's help capture the resonance of the cab, not just the sound that the speaker is producing.
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No that’s a common misconception. About 20ms is about all you need to completely capture a guitar cabinet response. The rest will just be partial reflections of the room it was captured in.
 
Colorado Axeman said:
Depending on how much they are truncated, the FM3 may not sound exactly the same as the Axe-Fx III. Longer IR's help capture the resonance of the cab, not just the sound that the speaker is producing.
Click to expand...
Even without that, the FM3 will not sound "exactly" as the AxeFx III because the FM3 amp block has few parameters missing, so logically there may be a difference on presets where the user tweaked specific parameters...

It doesn't mean it won't be able to sound as good as the AxeFx III though...
 
20ms is enough to represent the EQ curve of the speaker suspended on free air, but not in a cabinet.

Hit a cabinet with a hammer (impulse) and listen to the response.

Also the longer IRs allow the sound to interact with itself which adds to the depth and dimensionality of the sound.
 
Smittefar said:
20ms is enough to represent the EQ curve of the speaker suspended on free air, but not in a cabinet.

Hit a cabinet with a hammer (impulse) and listen to the response.

Also the longer IRs allow the sound to interact with itself which adds to the depth and dimensionality of the sound.
Click to expand...

That’s incorrect and the sort of of audio myth which keeps perpetuating for some reason.
 
Let me put it another way

I understand that some people like reflection free IRs for use with FRFR speakers.

I don't care for that. I am interested in sounds that are great in a PA or studio monitors. No studio sounds or PA sounds have ever been mic'd in a reflection free environment.

All my own listening tests have ended with the same result. I much prefer UltraRes IRs, and the same IRs in normal mode sound stiff and non dimensional to me.
 
Colorado Axeman said:
View attachment 63742
Graph of an Impulse response accelerometer fastened at the center of loudspeaker cabinet sidewall (100ms time window). There's clearly 'stuff' happening well beyond 20ms and even 100 ms.
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Room reflections. Unfortunately you need far more than 170ms to capture the room/reverb. The science and marketing are not in alignment on this subject.
 
As a contrary opinion, I couldn't care less. I won't use any IR blocks on the FM3.
Floorboards, to me, are for live use and I exclusively use real cabs live. For this it will be fantastic!

Studio side we have so many IR options it doesn't matter what the FM3 supports. Its a nice to have but not a necessity.
IR loader into the DAW of choice and you are done.
 
Smittefar said:
Hit a cabinet with a hammer (impulse) and listen to the response.
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Did you do this in an anechoic room?
There's a good chance that what you're hearing is room reflections actually.

Maybe a more truthful (but still unscientific) test could be to hit the cab with the hammer while keeping the other hand on the cab and see for how long you can feel the vibrations on the cab.

N.B.: it's advisable to hit the cab in a different point than where you put your other hand :p
 
For me the thing is, we don't know what's going on. Cab manual mentions truncation without any further details. FM3 manual mentions "Ultares" in the list of trademarks only. The promotional material released a year ago said "Ultrares", but now Ultrares is not mentioned in the FM3 web page.

I wish to know what I'm paying for.

Whether longer IR are good or bad may depend on cab, specific IR and personal preference. I am particularly concerned about acoustic instruments IR which may behave differently than guitar cabs. Yes, I am going to do tests and comparisons, but I'd prefer to be able to select IR length in the unit, and not worry about it before the purchase.
 
Smittefar said:
Let me put it another way

I understand that some people like reflection free IRs for use with FRFR speakers.

I don't care for that. I am interested in sounds that are great in a PA or studio monitors. No studio sounds or PA sounds have ever been mic'd in a reflection free environment.

All my own listening tests have ended with the same result. I much prefer UltraRes IRs, and the same IRs in normal mode sound stiff and non dimensional to me.
Click to expand...

And that's entirely fine - that's your sonic preference. But your previous post stated incorrect assumptions about guitar cabinet response as facts which is orthogonal to sonic preferences.


Colorado Axeman said:
View attachment 63742
Graph of an Impulse response accelerometer fastened at the center of loudspeaker cabinet sidewall (100ms time window). There's clearly 'stuff' happening well beyond 20ms and even 100 ms.
Click to expand...

Where is this graph from? How was the cabinet excited? How was the stimulus deconvolved? Hitting a guitar cabinet with a hammer is not the impulse response.
 
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Colorado Axeman said:
Depending on how much they are truncated, the FM3 may not sound exactly the same as the Axe-Fx III. Longer IR's help capture the resonance of the cab, not just the sound that the speaker is producing.
Click to expand...
Again, the FM3, according to all who have played through one, say it sounds the same as the Axe III, couldn't tell the difference. Don't know how much more "exactly the same" that can be. Larry Mitchell, for one, is using the FM3 live. If the tone was not the same as the Axe III, not sure he would be promoting or using it yet. He has a reputation to uphold, just as much as maintaining Fractal's reputation as a Fractal artist.

Not sure the purpose or meaning of editing the original comment: adding-"Use supplied air when oxygen concentrations are below 19%".
 
AlbertA said:
And that's entirely fine - that's your sonic preference. But your previous post stated incorrect assumptions about guitar cabinet response as facts which is orthogonal to sonic preferences.




Where is this graph from? How was the cabinet excited? How was the stimulus deconvolved? Hitting a guitar cabinet with a hammer is not the impulse response.
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That is exactly an impulse response. Using a sweep tone and deconvolution is just better if you want the perfect all frequencies in equal amounts mathematically perfect impulse. But hitting with a hammer is close enough and better at exciting the wooden construction. I think it's genius to use an accelerometer rather than a microphone. That suppresses the room reflections quite a bit although there is probably still a bit of room interaction.
 
Smittefar said:
That is exactly an impulse response. Using a sweep tone and deconvolution is just better if you want the perfect all frequencies in equal amounts mathematically perfect impulse. But hitting with a hammer is close enough and better at exciting the wooden construction. I think it's genius to use an accelerometer rather than a microphone. That suppresses the room reflections quite a bit although there is probably still a bit of room interaction.
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It's an impulse response of some other system - it's measuring something different (the material) not sound pressure.
You would first have to factor out the excitation signal (deconvolve hammer hit) and derive the sound pressure impulse response from the readings obtained from the accelerometer.
This response would not include any cabinet edge diffraction effects either.
Then you would have to still measure the impulse response of the driver(s) (so a mic is involved again) and convolve that with the derived response.

Or you can just use a microphone and actually measure what you are interested in - sound pressure variations.

So no, a hammer hit is not an impulse response of the units we are interested in (sound pressure variation)
 
No, the cabinet is part of the - well cabinet - this is not the sound of the speakers in the cabinet, this is the impulse response of the cabinet itself without speakers. It just shows that the response is longer than 20 ms. The hammer hit itself is definitely much shorter than 20 ms.

But you are right, it is much easier to put a cabinet in a great sounding room and just measure a fairly long IR using standard sweep technique.
 
The plot below is an ultrares impulse response.

4x12 HJ.jpg

As you can see we have a 0 dBFS peak at the 0ms mark and then "a lot" of energy all the way to 170ms.
That energy is mostly room reflections since it doesn't have the same steep and natural decay of the first few ms, BUT see at which level that energy resides past 40ms (the length of a Hi-Res IR - 2048 samples): -55 dB and below.
That would be barely audible (for a close mic'd IR at least, for room and guitar IRs it could be totally different)

To get an idea of how audible -55dB is, place, let's say, a delay block in a parallel row with mix at 100% and level at -55 dB. Can you hear the repeats?

PS: the IR is one I picked up randomly from this cab pack
 
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JoKeR III said:
Again, the FM3, according to all who have played through one, say it sounds the same as the Axe III, couldn't tell the difference. Don't know how much more "exactly the same" that can be.
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Do you have any example of anyone saying this other than that video of Leon last April? I don’t think anyone at Fractal ever claimed it sounds exactly the same. Soon enough we can all decide for ourselves.
 
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