Warren Labs: Impulse Response capture

Capture the reverb of a real space (a hall, your studio, that old-school auditorium) as an

impulse response (IR) you can load into a convolution reverb. The method is a **log sine

sweep + deconvolution**, the studio standard, robust against background noise.

Needs only Python 3 + numpy (the script has its own WAV reader/writer). Verify the math:

python3 ir_capture.py selftest          # → in-band IR correlation ~0.995 = PASS

What you need

• A speaker in the room (a decent full-range monitor or PA, one speaker, mono).
• A microphone at the listening position (one mic = mono IR; a spaced/stereo pair = stereo IR).
• A way to play a WAV through the speaker and record the mic. Your DAW is perfect.
• A quiet room (turn off HVAC/fridges; the quieter, the cleaner).

Steps

1. Make the sweep

python3 ir_capture.py make-sweep --out sweep.wav --seconds 8 --sr 48000

Use a longer sweep (--seconds 10–15) for big/loud spaces, for more noise immunity. Keep the

project sample rate consistent everywhere (48000 is a good default).

2. Play + record

• Put sweep.wav on a track and route it to the one speaker. Set a healthy but clean level

(loud enough to dominate the room noise; not so loud the speaker/room distorts).

• Arm the mic track and record while the sweep plays. Let it run through the 1 s of silence

at the end so the room's tail is fully captured.

• Export the mic recording as a WAV at the same sample rate → take.wav

(16/24/32-bit PCM or 32-bit float all work; mono or stereo).

3. Deconvolve into an IR

python3 ir_capture.py deconvolve --sweep sweep.wav --response take.wav --out my_room.wav

Out comes my_room.wav, the room's impulse response (mono or stereo, matching your recording),

trimmed to the direct-sound onset and normalized. Options:

• --length 4.0 keep a longer tail (big halls)
• --reg-db 70 cleaner/softer if the capture was noisy (higher = more smoothing)
• --predelay 0.01 keep more air before the direct sound

4. Use it

Load my_room.wav into any convolution reverb (Warren Labs Vault when it ships, or any IR

loader) and you're in that space.

Tips

• One speaker, mono. For a stereo IR, use a stereo/spaced mic pair, not two speakers.
• Levels: watch for clipping on the mic input; the sweep should sit well above the room hiss.
• Don't move during the take; keep the room still (no talking, no footsteps).
• Multiple positions make richer libraries. Capture a few mic spots and pick the best.
• No speaker? A sharp transient (balloon pop, starter pistol) is a cruder fallback: record it

and just trim/normalize the recording by hand, for lower fidelity with no deconvolution needed.

Save your spaces

Each my_room.wav is a portable file, so name them (studio_live.wav, school_auditorium.wav),

keep them in a folder, and that's your personal reverb library. (When Vault ships, the in-plugin

About panel will link here for these instructions, and users can load their own saved spaces.)