Free impulse responsesBack to top
Impulse responses recreate reverbs, real ambiences, mic'ed guitar cabinets and even guitar pickups. There are lots of free impulses that you can download and you can also create your own.
What is an impulse response?
It's a short audio file in WAVE format.
It's a recorded reaction of a system to a known stimulation and it contains information on how the system reacts to external change.
What does it do?
It recreates realistic ambience or guitar cabinet and microphone setup sound. Most guitar speaker cabinet simulations are based on impulse responses.
How do I use it?
Load impulse response file into convolution plugin such as:
How are IRs made?
Hardware is stimulated by known signal covering all audible frequencies. This known function is being convolved with hardware's function within the hardware and this signal is being recorded. Recording is then deconvolved that way so what's left is the hardware's function that can be further convolved with any signal.To make IRs you need:
- Necessary hardware - audio interface, microphone or cables depending on what you want to capture
- Test tone, this can be generated in Voxengo Deconvolver and Cockos Reaverb
- Deconvolution software like Voxengo Deconvolver, Cockos ReaVerb (included in Reaper)
Test tone, 24-bit, sinus sweep 20Hz-20kHz, mono, 12 seconds (right click and select to save target as...)Back to top
Guitar Cabinet IRs
It's possible to use different impulses at the same time and blend their tones. It's like using more than one microphone to record a real cabinet. It gives great results, as it's far better to change microphone type and placement rather than trying to fix everything with EQs and reverbs.
Below is an illustration of a guitar speaker with popular microphone placing spots. The closer a microphone is placed to speaker center, the more treble the tone is. There's a lot that could be written in this paragraph, but it's also great to try it out for yourself.
Microphones: SM57, MD421, SM7B, U87, C414, NT5 (room, also in stereo) Original impulses which recreate Metallica tones from many albums. YouTube tutorials on how to set it up right. Back to top
Convolution reverbs became popular quite a time ago, they are more realistic than reverbs based on algorhytms because they are based on responses of actual hardware and ambience.
Reverb impulses range from bathrooms, concert halls and studio rooms to Lexicon reverb units presets.Back to top
Guitar pickups IRs
Pickup sound can be simulated with impulse response. It's not accurate, because every guitar is equipped with its own pickups which alter the sound.
IR based guitar pickup replacing plugin. Lots of popular pickups and additional guitar material simulation.
- Bedroom Producer's Blog - Free sample shootout: 6 best free guitar cabinet impulse responses
- Convolution on Wikipedia
- Impulse response on Wikipedia
- Free impulse responses on KVR Audio forum