Impulse Responses (IRs) simulate the sound of speaker cabinets and microphone placements. Pair an IR with a NAM amp model or overdrive pedal for a complete "amp in a box" experience.
What is an Impulse Response?
An Impulse Response is a digital snapshot of how a speaker cabinet (and microphone) colors your sound. When you play through an IR, your signal sounds like it's coming through that exact cab and mic setup.
Common IR types include:
- 🎸 Guitar cabinets (1x12, 2x12, 4x12)
- 🔊 Different speaker brands (Celestion, Jensen, Eminence)
- 🎤 Various mic positions (on-axis, off-axis, room)
How to Add an Impulse Response
- Go to the Pedalboard tab
- Tap "Add Effect"
- Browse to IMPULSE RESPONSES category
- Select an IR you like
- Tap "Get" to add to your library
- While connected to Stratus/Nimbus, tap "Install"
Important: IRs must be installed over Bluetooth before they'll produce sound.
TONE3000 Integration
Chaos Audio has partnered with TONE3000 to give you access to thousands of free IR files created by the community.
To access TONE3000 IRs:
- Create a free account at tone3000.com
- In the Chaos Audio app, go to IMPULSE RESPONSES
- Sign in with your TONE3000 account when prompted
- Browse and download IRs!
IRs you download are saved to your Chaos Audio account and sync across devices.
IR Controls
Each Impulse Response has 2 adjustable parameters:
| Control | Default | Function |
|---|---|---|
| Mix | 100% | Blend between dry signal and IR-processed signal |
| Output | 100% | Master volume level |
Mix at 100% = Full cab simulation (typical for direct recording) Mix at 50-70% = Blended tone (useful when also using a real amp)
Multi-IR Packs
Some IR packs from TONE3000 contain multiple cabinet/mic options (e.g., different mic positions, cab combinations).
When you load a multi-IR pack, you'll see a dropdown selector to choose which IR to use. This lets you quickly compare different cab sounds without leaving the effect.
Technical Specs
- Sample length: Truncated to 1024 samples for optimal performance
- CPU usage: ~19.4% of Stratus's processing power
- File format: .wav files
CPU Usage
Impulse Responses use approximately 19.4% of Stratus's CPU.
This is efficient enough to pair with:
- NAM Amp Model (~52.5%) + IR = ~72% CPU ✓
- Multiple overdrives + IR = plenty of room ✓
- Full effects chain + IR = usually fits ✓
Common Signal Chain Setups
Direct Recording Setup: Guitar → NAM Amp Model → IR → Audio Interface (Complete amp + cab simulation)
Amp-in-the-Room Alternative: Guitar → NAM Amp Model → IR → FRFR Speaker or PA (Full-range speaker reproduces the "in the room" sound)
Hybrid Setup: Guitar → Overdrive → IR → Real Amp (clean channel) (Use IR for cab flavor, real amp for power section)
IR vs Cab Sim Effects
Why use IRs instead of a cab sim effect?
- Accuracy — IRs capture the exact response of real cabs
- Variety — Thousands of IRs available for any cab/mic combo
- Realism — Includes room reflections and mic characteristics
- Consistency — Same cab sound in any venue
Troubleshooting
No sound from IR? → Make sure you've tapped "Install" while connected to Stratus
IR sounds too dark/bright? → Adjust the Mix control, or try a different IR with different mic placement
Signal too quiet? → Increase the Output control
Need Help?
If you have any questions, email us at support@chaosaudio.com