# Engine audio credits

These audio files are adapted from Mazda MX-5 recordings and hosted with this portfolio. The rev loop is a **stock 1.6L facelift NB**, used as an approximation for the game's 1.8L NB2. The separate Freesound startup recording does not identify its engine displacement or generation. This is not an exact stock 1.8L NB2 recording set.

## Idle, ignition and engine stop

**“Miata Start and Stop.mp3” — TurboTheSergal** (June 22, 2020)

- Source: https://freesound.org/people/TurboTheSergal/sounds/523351/
- License: Creative Commons Attribution 4.0 International — https://creativecommons.org/licenses/by/4.0/
- Downloaded audio: https://cdn.freesound.org/previews/523/523351_11603686-hq.mp3
- Adapted files: `mx5-idle.wav`, `mx5-start.wav`, `mx5-stop.wav`.
- Changes: cropped at 7.00–9.20 s, 4.45–5.55 s and 9.60–10.25 s respectively; converted to mono 22,050 Hz / 16-bit PCM WAV, filtered below 28 Hz and above 4,200 Hz, level adjusted; idle loop ends crossfaded, one-shot edges faded. The original engine shutdown is used as the stall sound. These adapted files remain available under CC BY 4.0.

## Sustained rev loop

**“Mazda Miata MX5 NBFL 1.6 Stock - 10 - INT - Cabin - 4k RPM loop stereo.wav” — Soundholder**

- Source: the free SONNISS #GameAudioGDC 2020 bundle — https://sonniss.com/gameaudiogdc/
- Official bundle tracklist: https://docs.google.com/spreadsheets/d/1QqIcxJ7y0Acq3HAj9qQvFgvyeBjJ_7JvX8-GguUHIVk/edit
- Recording details: https://sonniss.com/sound-effects/mazda-miata-mx5-nbfl-1-6-stock/
- License: SONNISS #GameAudioGDC Bundle License, version 2.0 — https://sonniss.com/gdc-bundle-license/
- Adapted file: `mx5-high.wav`.
- Changes: converted to mono 22,050 Hz / 16-bit PCM WAV; 90 Hz high-pass filter to reduce cabin rumble; cropped at 9.5500–12.4955 s; DC offset removed, level adjusted, and loop ends crossfaded over 55 ms to create a 2.8905 s loop.
- Playback reference: approximately 4,360 RPM, estimated from the recording's 145.4 Hz four-cylinder firing frequency. Playback pitch and equal-power blending follow engine RPM. The limited recording coverage requires pitch shifting outside its original RPM range.

The SONNISS audio is licensed for use within this interactive portfolio. It is not offered as a reusable sound library and is not covered by any source-code license. Obtain recordings directly from SONNISS for other projects. The original authors retain their rights and do not endorse this portfolio.

The previous HKS modified-exhaust rev recording has been replaced. Recordings downloaded September 10, 2026; stock rev loop adapted September 11, 2026.