How we built one hundred kits in six months

"The kit catalog is the part of SONICHAOS that does not run on AI." — Aviv Mor, founder

One hundred kits, six months, six rooms, twelve producers. The catalog at /kits exists because twelve people sat in twelve sessions and wrote loops a working creator could open in a project and ship the same week. This post is the operations playbook. Mic chains, BPM grids, key labels, mastering chain, folder convention.

The mic chains that show up in every kit

Three chains carry most of the catalog. They are not secret and they are not exotic. They are the chains a working pro audio room runs because the gain staging is predictable and the parts come back when they break.

The Berlin room records strings in a 5.2 m by 4.1 m live space with Royer R-121 ribbons on the cellos and a stereo pair of DPA 4011 overheads. The signal goes into a Universal Audio Apollo x8p through the 1176 Vintage preamp at 4:1 compression with a slow attack and a fast release.

The Brooklyn room records drum design through a Shure SM7B into a Cloudlifter CL-1 for one-shot rendering, and through the Manley Variable Mu on the master bus for the drum bus print. The print through the Vari-Mu is what makes the Brooklyn drum kits sound like they were tracked together and not assembled.

The Kyoto room runs Hana Okabe's vocal chops through a Sony C-100 into a Grace Design m101 preamp. The chops in the catalog are sung performances, not pitched-up speech. The breath noise reads as a vocalist's breath, not a synthesised breath.

BPM grids per family

The catalog has ten families and the BPM grids per family are deliberate. A producer writing for the trap and drill family does not get to write at 110 BPM. The grid is set so a creator who needs exactly 144 BPM drill material can pull from any kit in the family and stack without warp.

• Trap and drill: 134 to 160 BPM, with the drill cuts living at 140 to 144 BPM and the trap cuts at 134 to 138 BPM.
• Cinematic strings: 60 to 90 BPM, with a half-time interpretation written into the MIDI so the loop can sit on a 120 BPM bar.
• Lo-fi hip-hop: 76 to 92 BPM, BPM-locked per kit. No stretched loops in the catalog.
• Dark techno: 132 BPM, the singular grid. The whole family writes at 132 BPM, which is the Friday-night warm-up tempo at the rooms the producers actually play.
• Future bass: 140 to 160 BPM with half-time feels written in. The side-chain trigger lives in the MIDI so the user can re-route to a different kick.
• Synthwave: 96 to 110 BPM. The 80s grid sits in the middle of that window for the Coastal AM-style kits.
• Ambient and drone: tempo-free. Beats per minute is the wrong unit for a four-minute drone WAV; the kits ship without a BPM tag and the DAW reads the bar count from the WAV cue points instead.
• Hybrid orchestral: 60 to 120 BPM with the trailer grid sitting at 120 BPM half-time.
• Drum and bass: 173 BPM, the grid the genre has converged on for jungle, neuro, and liquid alike.
• Vocal chops: keyed in A minor, C minor, and E minor; the chops sit on the producer's tempo and re-time inside the user's project.

Key labels in two notations at once

Every kit ships keys in standard notation in the filename and in Camelot notation in the metadata sidecar. Mixed-in-Key reads either; the redundancy makes the kits usable in both an academic mixing workflow and a DJ-style harmonic mixing workflow.

The convention reads kit-slug_loop-03_Cmin_5A_140bpm.wav. The slug covers the kit. The loop number is a sequence inside the kit. The key is standard. The Camelot tag is the wheel position. The BPM is the project tempo, not the loop's natural rate.

The redundancy costs us seven extra characters in the filename and saves the user the import-time question of which notation they prefer.

The mastering chain that ships every kit

Every kit goes through the same mastering chain before it leaves the producer's machine. The chain runs in this order, every time:

1. FabFilter Pro-Q3 on the bus, surgical only. Cuts at narrow Q below 60 Hz on anything that does not need to live there.
2. Tube-Tech CL1B at 2:1 compression with a 30 ms attack and a 100 ms release. The reduction sits between -1.5 and -3 dB on the average loop.
3. FabFilter Pro-L 2 with the true-peak ceiling at -1.0 dBTP and the integrated LUFS target at -14 LUFS. The ambient drone family ships at -16 LUFS for app-context listening.
4. iZotope RX 10 De-Clip pass on any loop that pushed past the ceiling during tracking. The corrected WAV ships; the original does not.

The chain is documented inside every kit folder as a plaintext mastering.txt. The user does not need to read it. The user mastering their own track on top of the kit does.

Folder convention every producer hands in

Every kit folder lands in the catalog with the same structure. The folder is what the user unzips; the structure is what their DAW reads.

kit-slug/
  loops/
    kit-slug_loop-01_Cmin_5A_140bpm.wav
    ...
  one-shots/
    kit-slug_kick_01_C.wav
    ...
  midi/
    kit-slug_chord_progression_01.mid
    ...
  presets/
    serum/
    diva/
  stems/                  (flagship tier only)
  mastering.txt
  README.md
  receipt.pdf             (signed ed25519, generated at download)

The README is a single page. The mastering text is the chain above. The receipt is the licence proof. The structure ships the same way for every kit so a user pulling from twenty kits at once does not have to re-learn the layout for each.

The next kit in the catalog will land in this folder shape too. Working creators get to keep their muscle memory.