The more IRs are used, the more realistic the amp/cab in the room sound is

[Jason Scott]

If multiple IR's was the be-all-end-all affecting realism, then the Headrush and Helix would sound just as realistic as the Axe-Fx III.

 

[TheRedDevil]

Sure and if you install Windows 11 on a Commodore C64 it will be as fast as on a modern PC

 

[steadystate]

No.

 

[boyce89976]

If the IR’s were 100% phase coherent then with two IR’s totally in phase you would have a slight increase in volume only, no additional character would be imparted (like 2 identical or near identical IR’s).

Also if an IR was altered or transformed beyond the “time alignment” to be perfectly phase aligned I’d imagine the result would be more like a quite plain eq curve (I think the smoothing parameter does this?) without the random part that makes them sound different and interesting. It would allow for absolute perfect phase alignment through the frequency spectrum though.

Edit - Also happy to be educated otherwise, it has been many, many years since I studied this material.

Frequency amplitude and time alignment are two different, but inter-related things. Two different mics can be in phase (time aligned), and still sound completely different. A 57 and a 121 will never sound the same without some outside EQ treatment. Their blended tone won't sound like either one by itself.

There will always be minor phase differences because two mic's can't occupy the same space (except in Fractal land).

You can see this in CabLab. You can combine two mics, and the resulting curve is unlike either mic. Part of that is amplitude differences at different frequencies, part is minor phase differences.

 

[Jason Scott]

Sure and if you install Windows 11 on a Commodore C64 it will be as fast as on a modern PC

Exactly, and if you use multiple IR's in a Helix or HeadRush, it will sound every bit as realistic as the Axe-Fx III. For that matter, Two Notes Genome can use up to 20 IR's, thus it sounds the most realistic.

 

[TheRedDevil]

But not the basis, e.g. amp algorithms and CPU power are different. The result is not the same.

 

[Jason Scott]

But not the basis, e.g. amp algorithms and CPU power are different. The result is not the same.

Not the point.

You specifically stated, 'The Axe-Fx III itself provides up to 8 IRs that can be used at the same time. I think that's one of the main reasons why the Axe-Fx III can generate much more realistic sounds.' So, on one hand, you're arguing that the number of simultaneous IRs used in an effects processor is the limiting factor that determines how realistic it sounds. Meanwhile, you're also sarcastically implying that hardware is the limiting factor: 'Sure, and if you install Windows 11 on a Commodore C64, it will be as fast as on a modern PC.'

 

[Smittefar]

No matter how many IRs you blend they can all be mathematically transformed to a single (two for stereo) IR without any difference in sound. CabLab can do this.

 

[TheRedDevil]

Please refer to the remarks in first post. It's just a title to motivate you for this discussion. From my point of view it's really interesting to read your arguments.

 

[Greg Ferguson]

Please refer to the remarks in first post. It's just a title to motivate you for this discussion. From my point of view it's really interesting to read your arguments.

So this was an academic discussion, not at all about actually finding a better solution?

The thing about IRs is they’re basically EQ, and additive. Find where they result and use that curve and you should be done.

 

[TheRedDevil]

I think the theory does not exclude practice but rather is the basis for it. The probability of achieving a good sound probably increases with the combination of IRs, but it can also fail. I still think 4 IRs should be the maximum. But just 1 IR is probably often not enough.

 

[laxu]

I think the theory does not exclude practice but rather is the basis for it. The probability of achieving a good sound probably increases with the combination of IRs, but it can also fail. I still think 4 IRs should be the maximum. But just 1 IR is probably often not enough.

I think your assumption here is that 1 IR = 1 mic/cab. But a single IR can be 100 cabs/mics blended into one if whatever software you use to do that is capable of it.

For example the ML Sound Lab MIKKO plugin can mix up to 9 mics/cabs where each mic can be a different model, position etc on a different cab. It's totally unneccesary excess to be able to do that and realistically 1-4 mics on a single cab is more than enough for most usecases.

 

[yek]

I think the theory does not exclude practice but rather is the basis for it. The probability of achieving a good sound probably increases with the combination of IRs, but it can also fail. I still think 4 IRs should be the maximum. But just 1 IR is probably often not enough.

42.

 

[TheRedDevil]

Cheers

 

[Jason Scott]

I think your assumption here is that 1 IR = 1 mic/cab. But a single IR can be 100 cabs/mics blended into one if whatever software you use to do that is capable of it.

There's also Tone Match, which can capture the sound of multiple IR's.