devices · Helix Stadium XL Floor · reference · cabs and IRs
cabs and IRs
What an IR is
An impulse response is a recording of what a mic'd speaker cabinet does to a sound. Someone plays a frequency sweep through a real cab, records it, and mathematically removes the sweep. What is left is the cabinet's fingerprint, which can be applied to anything. It is the same idea as a convolution reverb, with a much shorter decay. Each IR captures one speaker, in one room, with one mic in one place.
cab block or IR block
A Cab block holds two slots, and each can be a Guitar Cab, a Bass Cab, or a Cab IR. You choose per slot, and you can blend one of each. Adding an Amp block adds a matching Cab automatically. That is right into a full-range system and wrong into a real guitar cab. Turn that behavior off from the Amp's sidebar if your rig always ends in a real speaker.
Helix Stadium Owner's Manual 1.3.2 · HX Edit Pilot's Guide 3.80deleting an IR breaks the presets that used it
Delete an IR that a saved preset references and that preset's Cab tab reads UNRESOLVED. It does not load the wrong cab without warning, as numbered slots do. Tap the UNRESOLVED tab, choose a new IR or Cab model, and save the preset to keep the change.
Loading an IR
The Stadium holds up to 2,048 IRs. Unlike the rest of the family, it keeps them as a named library, not a numbered rack of slots.
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import through the Helix Stadium application
Free for macOS and Windows. The library lives on the device; the app is how files get there.
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WAV only, and it normalizes everything
Whatever the source file's length, sample rate, bit depth or channel count, it is processed internally as a 2048-sample, 48 kHz, 32-bit float, mono file.
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then pick it from the Model List
Tap Cab IR in the sidebar to jump to the bottom of the list, then 2048 IR, and your User Cab IRs folder shows everything you have imported by name.
a big import makes the next boot slow, once
Import several hundred IRs in one session and the next power-on takes a few extra minutes while the library indexes. It is not a fault, and later starts are normal.
old Hybrid Cabs get converted
The Stadium does not include the Hybrid Cab models from pre-3.50 Helix firmware. Import a Helix or HX preset containing one and it is converted to a new Cab automatically. Line 6's own note: it may sound better, and will sound different.
a Clone does not add a cab for you
Amp Clone blocks do not offer the automatic Add Cab Block behavior. If you captured an amp without a speaker sim or IR in the signal, add the Cab block after the Clone yourself. Without it you hear an amp with no speaker.
IRs are in the backup
A microSD backup takes all your user data, IRs included. Restoring one overwrites what is on the modeler, so the library goes back exactly as it was with no separate import.