devices · Axe-Fx III · reference · cabs and user IRs
cabs and user IRs
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What a User Cab is
An impulse response is a recording of what a mic'd speaker cabinet does to a sound. A frequency sweep is played through a real cab and recorded, then the sweep is removed mathematically. What remains is the cabinet's fingerprint, and it can be applied to any signal. Fractal call these User Cabs when they are yours and Factory Cabs when they shipped with the modeler. They are the same kind of thing.
how much room you have
2,048 factory cabs and 2,048 memory slots for your own, plus 16 scratchpad memories to audition a cab before it takes a slot. User cabs sit in two banks. A third bank takes the newer FullRes format, which allows an IR up to 1.37 seconds, longer than UltraRes.
Axe-Fx III Owner's Manualtwo file extensions, and only the .syx file loads
An IR you send to the modeler is a MIDI System Exclusive file: .syx. The newer .IR extension is only for re-mixing inside Cab-Lab, and the hardware does not take it. Fractal flag this: a download page often offers both side by side, and the .IR file does nothing once sent.
Getting them on there
Loading a User Cab
Two routes: the editor for more than one file, or Fractal-Bot for one at a time.
- step 01
the editor: Axe-Manage Cabs
Drag and drop cab files into memory slots, and manage what is already there: copy, paste, rename and drag-and-drop reordering, which the Helix librarian lacks. Use it for a Cab Pack: you load, audition and organize in one place. Press SAVE when you are done.
- step 02
or Fractal-Bot, one at a time
Open a Cab block and set Cab 1 to the bank and number you want to fill. Send the .syx from Fractal-Bot and the modeler stores it there. Fractal-Bot can also transmit whole banks at once.
- step 03
then point the Cab block at it
Select the Cab block, press EDIT, and change the cab to the bank and number you transmitted to, such as "USER 1, #215".
Notes
note the bank and slot as you send
A cab lives at a Bank and a Number ("User 1, #215"), and the Cab block selects it by that address, not by name. Afterwards, select the number you transmitted to. A preset someone shared expects their slot numbering, not yours. Write the number down while you send.
user cabs are NOT in a System backup
Unlike older Fractal modelers, the Axe-Fx III keeps user cabs outside the SYSTEM area. A System backup does not protect your cabs, so back up the cab banks separately. Restoring a System backup never overwrites them.
where to get them
Fractal's shop sells professionally produced Cab Packs, including ones from third-party producers. Axe-Change, Fractal's file-sharing site, is a large free library. To capture your own cabinet, use the modeler's IR Capture utility. It needs a mic and a preamp, plus either a flat full-range power amp or a speaker-level DI box.
what Cab-Lab is for
Cab-Lab is an IR mixer. It blends several IRs into one, the way an engineer blends several mics on a real cab. Fractal also recommend it for capturing, because its interface is easier than the built-in utility. You do not need it to load an IR someone else made.
capture uses Output 2 Left
The built-in IR Capture utility sends its sweep from OUTPUT 2 LEFT. Set Output 2's "Copy Output 1" to OFF first, or the capture will not work.