Speaker Impedance Curve: Why is this in the Amp Block instead of the Cab block?

it doesn't bother me in the least that there are fewer speaker impedance curves than IRs
That wouldn't make sense in any case as the curve is the combination of speaker and cabinet.

There may be dozens or hundreds of IRs of the same speaker+cab combo.
 
I see doing this better more as a next gen feature.

IMO the current top tier for cab simulation is plugins like ML Sound Lab MIKKO that let you move multiple microphones around a virtual speaker. The way it works is that it blends together a large matrix of IRs as you move the mic around. You can blend different mics, different cabs etc without dealing with stupid file browsers. Quad Cortex has a simplified version of this (one mic per speaker, two speakers or mics in a cab block) and it greatly simplifies getting your preferred sound out of a specific cab and takes out the trial and error.

If Fractal implements something similar for its stock cabs in the next gen Axe-Fx, having the amp model impedance curve follow the cab block speaker selection becomes a more feasible feature as each cab is no longer "this big list of different mics/positions" but "this cab/speakers". Of course this becomes trickier when dealing with non-cab sim situations so having the impedance curve selection in the amp block is still the right place, but for cab sims at least it could be automated to select the appropriate curve.
The only downside I see is that it would make it more complicated to make IRs of one's own speakers....
 
It does kind of fascinate me that not only does the cab play the amp a little in the real world, but the room itself must also have an effect too. I'm guessing it's pretty small and difficult to measure, but I tend to think of the room playing the amp as well as the amp playing the room nowadays. This came down to my questioning low frequency resonances from my Axe FX III rig in my studio with a Fender Princeton Reverb model, and I thought they just couldn't be that loud from a 12 watt tube combo with a 10" speaker. So I dragged my PR into the room, and guess what? Same frequencies exactly resonated at deafening volume!

Liam

Yes, small, but likely measurable. Cab resonances show up in the ICs as little to medium sized dips and/or spikes along the curve, where the resonances make the speaker slightly easier or harder to drive at that those frequencies, which adds to or subtracts from the natural inductive load of the speaker coil at those frequencies....
 
I guess I'm in the minority as I don't really care where it is. :)
Me too. Until there is enough processing power or preset data storage for a compound curve of all the active IRs' ICs to be saved as cab data (to be used by the amp block in determining how the amp should react to it/them), it makes sense to be where it is.

As someone up-thread said, the IC is the electrical part of the cab's properties, and the IR is the acoustic part of the combined cab/mic's properties....
 
Hi, apologies for the question, but is the IC a property of the cabinet, or the actual speakers (or both). I ask because the 2x12 Class A 30W IC makes no mention of speaker (greenback or Alnico), yet there's another non AC30 IC "2x12 Guy Tron Alnico Blue" IC that says "Alnico Blue".

If I'm using an 2x12 AC30 Alnico blue IR, do I use the default Class A 30W IC or the Guy Tron Alnico Blue one?

If the former, was the cab used for the Class A 30W IC loaded with greenbacks or alnicos?
 
The impedance function is a property of the relation between amps & cabs. If we want to model reality, the function must be linked to the cables/shunts! And is the result of a function, with the functions of cabs & amps impedances as variables.


I had a similar thought - or make the IC it's own block..... but that wouldn't be realistic and would clog up the grid with things that don't exist in real effects chains.

I see why it is in the AMP block, and probably prefer it that way at this point.
 
Hi, apologies for the question, but is the IC a property of the cabinet, or the actual speakers (or both).

The speaker itself is the bulk of the IC, but the cab it is in affects the IC via adding/subtracting from the raw speaker IC at the cab's resonances....

I ask because the 2x12 Class A 30W IC makes no mention of speaker (greenback or Alnico), yet there's another non AC30 IC "2x12 Guy Tron Alnico Blue" IC that says "Alnico Blue".

If I'm using an 2x12 AC30 Alnico blue IR, do I use the default Class A 30W IC or the Guy Tron Alnico Blue one?

If the former, was the cab used for the Class A 30W IC loaded with greenbacks or alnicos?

Try both and use whichever sounds better....
 
I do not use a cab block. My AXE III goes through a Matrix Amp and 2 Bogner 1x12 Cubes with Cream Alnicos.

I just cycle through the impedance curves and pick the one that sounds the best, I like the GreenBack 4x12's for Marshall Type amps and the SF 2x12 deluxe for the Fender amps, usually.
 
I do understand there's arguments on both camps, and that the solution is perhaps an inevitable compromise.

But from usability perspective it's a bit counterintuitive - and hard to remember - that one should also tweak the amp block after switching say from a v30 to a Greenback IR in the cab block. I might be wrong but I would think that setting the IC is something you do very often when switching cabs, and very occasionally when switching amps. Again from usability perspective I believe the user workflow should guide the UI layout as opposed to where stuff is implemented. If the user is switching cabs, making all strongly relevant settings quickly available makes sense to me.

Or perhaps the impedance curve setting could simply show at both blocks, kind of a linked setting.
 
I can understand the approach to simplify things well, but would not give up the flexibility for this.

Fractal Audio builds professional products that also have a certain claim to deal with it. The forum, the wiki and many good people help to understand unclear things better.

How can a solution look like?

Currently, with the AMP block, the appropriate IC is selected when choosing an amplifier. This should remain basically so that all presets with and without CAB can be used without problems.

With the IRs integrated in the FW, I could imagine that FAS manages to assign a suitable IC. So for F1, F2 and L.
If I now edit a new preset with CAB or an existing one and select a factory IR, then and only then the IC in the AMP block is changed accordingly.

With the user IRs it is not so easy to realize an automatic link because there is no information in the IR.

So a link would have to be determined by the user. This would mean that when importing an IR I have to determine the appropriate IC. So the CAB Manager offers itself for this in future.
If I do not determine an IC for the imported IR, the selected amplifier in the AMP block determines the IC. So now actual.

However, this does not solve the problem if I have several IRs that may use different ICs. I wonder how realistic it is to operate an AC30, for example, with 2 or 3 different CABs (loudspeaker configuration) at the same time, which does not work so easily in the real world. But I am also more for a classic placement. But everyone should find his part here.
 
I run the "totally flat" Cab IR with my SS Amp + Real Cab - totally transparent but adding the ability to low/hi cut my real cab (+ IC if it was there), and allows switching over from FR to real cab without having to turn off cab modelling or footswitching off the cab block (just switch cab block channel).

Where did you find that? Totally flat IR?
 
Instead of a mic position algorithm an additional peq page in the cab block would already help a lot. Once tweaked I could save and recall perfectly taylored IRs. I could built my own collection of tweaked IR blocks.
 
I can understand the approach to simplify things well, but would not give up the flexibility for this.

Fractal Audio builds professional products that also have a certain claim to deal with it. The forum, the wiki and many good people help to understand unclear things better.

How can a solution look like?

Currently, with the AMP block, the appropriate IC is selected when choosing an amplifier. This should remain basically so that all presets with and without CAB can be used without problems.

With the IRs integrated in the FW, I could imagine that FAS manages to assign a suitable IC. So for F1, F2 and L.
If I now edit a new preset with CAB or an existing one and select a factory IR, then and only then the IC in the AMP block is changed accordingly.

With the user IRs it is not so easy to realize an automatic link because there is no information in the IR.

So a link would have to be determined by the user. This would mean that when importing an IR I have to determine the appropriate IC. So the CAB Manager offers itself for this in future.
If I do not determine an IC for the imported IR, the selected amplifier in the AMP block determines the IC. So now actual.

However, this does not solve the problem if I have several IRs that may use different ICs. I wonder how realistic it is to operate an AC30, for example, with 2 or 3 different CABs (loudspeaker configuration) at the same time, which does not work so easily in the real world. But I am also more for a classic placement. But everyone should find his part here.
What about a lookup table: IR#, Impedance curve #?
If there is an impedance curve, than load it. If there are more IRs, the "harmonic media" of the impedance curves (college vague memories...).
If there is no impedance curve, let the user choose the default one (the one previously in the amp block, or the global one, ...).
When a cab is selected/inserted, then the SI in the amp block use the curve as above, then could be edited in amp block (as now). So we have only one curve to care about, in the amp block, same as now.
 
I have to add one more info about the IC.

The ICs are only stored in the FW, also the ICs that the user assigns to the imported IR.

So no ICs are imported with the IR.

The IC can only be extended by FAS.
 
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