Guitar Cabinet IR Guide: What Impulse Responses Do and How to Choose
Cabinet impulse responses (IRs) are the most important part of your amp sim tone. Learn what IRs are, how to choose them, and why they matter more than the amp model.
The cabinet IR is the single most impactful part of your digital guitar tone. A great amp model through a bad IR sounds bad. A mediocre amp model through a great IR sounds good.
What an IR does
A cabinet IR captures the frequency response of a speaker cabinet — how it colors the sound, what frequencies it emphasizes or cuts, and how the room reflections shape the tone. It's equivalent to mic'ing a real cabinet.
How to choose
- Celestion Greenback 4x12: The rock standard. Present midrange, smooth top end. Works for most rock and blues.
- Celestion V30 4x12: More aggressive upper mids. Standard for metal and hard rock.
- Jensen C12N 1x12: Clean, balanced. Works for jazz, country, and clean pop.
- Mesa 4x12 with V30s: Tighter low end than standard V30. Modern metal.
When to change IR
Use one IR for practice consistency. Switch when the tone doesn't fit the song. Don't IR-shop mid-practice — it's a rabbit hole that replaces playing with tweaking.