Who said that? You don't HAVE to do anything and you presets will sound exactly as they were before.So basically your saying we have to take note of the cab on every preset, reload the amp, then reset the the cab if it changes to what it was before, then save the preset, for all 500 presets?
The way I read your note, no presets are changed until you reload the amp. When you do that, there is a chance that the cab has changed, so If you want the preset to have the same IR, you need to keep the original. ( which will now have the new parameters , correct?)Who said that? You don't HAVE to do anything and you presets will sound exactly as they were before.
Selecting an amp does NOT change the cabinet IR. It changes the speaker impedance model. Two very different things.The way I read your note, no presets are changed until you reload the amp. When you do that, there is a chance that the cab has changed, so If you want the preset to have the same IR, you need to keep the original. ( which will now have the new parameters , correct?)
don’t worry, just me trying to picture how this is working. I’ll get it eventually
That's what I was gathering but its hard for some of us civilians.Selecting an amp does NOT change the cabinet IR. It changes the speaker impedance model. Two very different things.
I'm working on a idea to use the outputs of the Axe-Fx directly along with a special cable to allow field measurements by users.
Maybe a "convert all speaker impedance curves" setting hidden somewhere in the global settings that hides after one use? I imagine the number of people who have touched this impedance curve is fairly small, so the old defaults are likely still set at factory settings....In retrospect perhaps I should've updated the amp blocks to use the new impedance curves. It sounds better and the average user probably wouldn't care about the change in the sound of his preset.
In retrospect perhaps I should've updated the amp blocks to use the new impedance curves. It sounds better and the average user probably wouldn't care about the change in the sound of his preset.
the bigger problem for me is experimenting with cabs...there are plenty in the axe and as i preview the different cabs, if i could get the default response behavior loaded in the amp block automatically...i could rifle thru authentic sounds much easier!Maybe a "convert all speaker impedance curves" setting hidden somewhere in the global settings that hides after one use? I imagine the number of people who have touched this impedance curve is fairly small, so the old defaults are likely still set at factory settings....
I thought the AC20DLX Speaker Cabinet sounded kind of muddy & took away from the beautiful sparkle. Set the LF Res Q (1.787), LF resonance (5.83) & HF resonance (7.5) back to factory patch default & it sounds amazing. Even after those changes, it shows a different speaker graph in the speaker page of Axe edit compared to the factory patch default.Used the AC20 with AC20 IR and AC20 curve this morning with the band. Holy smokes it sounds amazing with my old telecaster!
No.
A tube power amp is a transconductance amplifier, voltage in - current out. A speaker is a voltage transducer, voltage in - sound out. Since the power amp is driving current the voltage at the speaker is the current times the impedance of the speaker (Ohms law V = I*R). The voltage therefore is dependent upon the impedance.
A solid-state power amp is a voltage amplifier, voltage in - voltage out. Since the power amp is driving voltage the voltage at the speaker is NOT dependent on the impedance of the speaker.
When an IR is captured (correctly) it is done using a solid-state power amplifier so the effects of impedance do not influence the measurement. Some people try to use tube power amps to capture IRs. This is incorrect methodology.
The Axe-Fx power amp simulation is a transconductance simulation. It uses a simulated speaker impedance to derive the output voltage that then drives the simulated cabinet (IR).
Firmware 11.xx has 47 (and counting) speaker impedance curves that you can select that allow for different power amp transconductance responses. Moreover the impedance simulation is now a high-order network that simulates the perturbations in impedance due to cabinet resonance.
If you are using a conventional guitar cab and solid-state power amp ideally you would want to know the impedance curve of the cabinet. This requires special test equipment although I'm working on a idea to use the outputs of the Axe-Fx directly along with a special cable to allow field measurements by users. At this time the impedance curve matching is a Matlab program though and requires some hand-tuning.
In a perfect world, shouldn't there be a dedicated speaker impedance curve for every IR that comes with the Axe FX?
Ideally an IR would contain two IRs: one conventional IR and one that represents the impedance. But the average IR producer has no idea how to capture the second one.Ive been thinking the same thing. Why not embed metadata into an enhanced speaker IR that includes impedance, resonance, mic, amp info. Then let the Axe-FX configure the amp.
The problems with that are fourfold, at least:the bigger problem for me is experimenting with cabs...there are plenty in the axe and as i preview the different cabs, if i could get the default response behavior loaded in the amp block automatically...i could rifle thru authentic sounds much easier!
Yes pleaseI'm all for this. 95% of people won't know...just that it sound bettter.
This ^^^^Ideally an IR would contain two IRs: one conventional IR and one that represents the impedance. But the average IR producer has no idea how to capture the second one.
Yes I understand that...but if an IR does have the associated response data for a power amp, then the preview function in axe-edit could let you:The problems with that are fourfold, at least:
1. Not all of the cabs each have a curve in the list.
2. Additionally, any 3rd party cabs can't be predicted by FAS, so their impedance curves are not going to be available in the Axe.
3. The cab block would have to trace backwards from its input to detect which amp block it is downstream from in order to even know which amp block's impedance curve to switch, as the impedance curve is stored in and used by the amp block, to determine how the amp responds to its load.
4. The cab block can hold multiple IRs in parallel. The curves for the combination are not likely to be in the list. See #1 and do some statistics/probability math to find how many different combination curves would need to be available, given the huge number of even just factory cabs that could be loaded in each slot. That's a LOT of curves. Calculating a curve and applying it might be possible if all the cabs had curves, but, as mentioned in #1, they don't.
I think the best we can hope for is to choose an impedance curve for a similar cab and use that.
The IR makers might like a reason to differentiate. I think packs of meta-enhanced IRs would do well, especially if they are far field.Ideally an IR would contain two IRs: one conventional IR and one that represents the impedance. But the average IR producer has no idea how to capture the second one.