# RaceSounds prototype audio

Downloaded October 23, 2026. These are prototype sources, not verified recordings of named performance cars. No manufacturer affiliation is implied. Actual source RPM is unverified for every loop; the UI's reference RPM is an adjustable tuning assumption. We selected the licenses below from the alternatives offered on each source page.

## Recorded engine — qubodup

- Work: **Car Engine Loop 96kHz, 4s**, by **qubodup**.
- Source: https://opengameart.org/content/car-engine-loop-96khz-4s
- Download: https://opengameart.org/sites/default/files/engine-loop.7z
- Selected license: **Creative Commons Attribution 3.0 Unported** — https://creativecommons.org/licenses/by/3.0/
- Runtime file: `public/audio/recorded-engine.wav`, copied unchanged from `engine-loop/engine-loop-1-normalized.wav` in the archive.
- Changes during runtime: browser sample-rate conversion, per-channel DC removal and peak normalization in memory, loop crossfading, variable playback rate, load-dependent filtering, gain and limiting. Any downloaded audio take using this source is an adaptation; retain this attribution when sharing it. No endorsement by the original author is implied.
- SHA-256: `CF504EC899929570D68C1F3A77AAD2DA60C6D28BF60BE535504598692EA46089`

## Phone recording A and B — GGBotNet

- Work: **Car Sound Effects Pack (Low Quality)**, by **GGBotNet**.
- Source: https://opengameart.org/content/car-sound-effects-pack-low-quality
- Download: https://opengameart.org/sites/default/files/car_sound_effects_pack.zip
- License: **CC0 1.0** — https://creativecommons.org/publicdomain/zero/1.0/
- Runtime files: `phone-engine-1.ogg` from `Car_Engine_Loop.ogg`; `phone-engine-2.ogg` from `Car_Engine_Loop_2.ogg`. Copied unchanged.
- Source describes phone recordings at 64 kb/s. These deliberately provide a low-quality comparison. Same runtime processing as above.
- SHA-256 A: `D0F8B89066792CCF23895F6D5BBC7FB1A0363691324B72C921099E57828FEC96`
- SHA-256 B: `6F1A08688B1956BBC573D4D4F148D8F41902058DD136310BC648E6F5E24B3775`

## Legacy game loop — domasx2

- Work: **racing car engine sound loops**, by **domasx2**.
- Source: https://opengameart.org/content/racing-car-engine-sound-loops
- Download: https://opengameart.org/sites/default/files/loop_0.wav
- License: **CC0 1.0** — https://creativecommons.org/publicdomain/zero/1.0/
- Runtime file: `legacy-loop.wav`, unchanged download of `loop_0.wav`.
- The author describes cutting and looping a public-domain car recording and confirms in the page comments that the upload was remade from a public-domain sample. We downloaded only the base loop; the other files are pitch variants, not separate engines.
- Same runtime processing as above.
- SHA-256: `69D74B106509037CE547429E4C3F9AE906B0FFFE88D0BB8B3B5A8B0CFC239048`

## Startup clip — looneybits

- Work: **Car engine Start Up 02**, by **looneybits**.
- Source: https://opengameart.org/content/car-engine-start-up-02
- Download: https://opengameart.org/sites/default/files/engine_start_up_01.wav
- License: **CC0 1.0** — https://creativecommons.org/publicdomain/zero/1.0/
- Runtime file: `startup.wav`, unchanged download. Played only by the separate startup button, not used as an RPM loop.
- SHA-256: `026311134479A4BB21F7F9A4A64C2B47791373C6E3613D36045387EEE0FA0B23`

## Procedural V8 reference

Original code in `src/engine-worklet.js` synthesizes a combustion-like pulse train with harmonics and load-dependent filtering. This is a comparison sound, not an authentic recording or a physically validated engine model. No external audio assets are used for it.

## Retained downloads

`public/audio/originals/` retains downloaded archives and the original legacy/startup WAVs. Runtime loop assets are separate for direct loading. `download-manifest.json` records source URLs, dates, hashes and sizes. The application makes no runtime requests to the source websites.

For production, replace these single-loop sources with licensed, RPM-calibrated on-load/off-load banks. A large sample pack does not itself solve GPS or speaker latency.