Impact Engine
Impact Engine controls the intensity at which Audio-to-Haptics plays, based on classification of the audio content.
Razer Sensa HD Haptics performs the audio-to-haptics conversion, configured by the profile the user selects in Synapse. Impact Engine is a separate feature that determines how much of that conversion is expressed at any moment. The profile sets the character. Impact Engine sets the intensity.
Behaviour
System audio output is analyzed continuously on the player's machine by a small on-device classifier, which identifies the kind of sound present rather than measuring its level. That is a different question from the one a compressor answers. A compressor responds to level. Impact Engine responds to meaning.
| Audio content | Haptic response |
|---|---|
| Percussive, high-energy events such as gunfire, explosions and impacts | Strong |
| Sustained ambience and environmental sound | Low |
| Speech | None |
| Music | None |
| Unrecognized content | None |
When more than one kind of sound is present in the same moment, which is normal in any real mix, the most impactful of them is what the player feels.
What this means for your mix
The classifier hears your final output bus, after everything your engine does to the signal. Whatever reaches the player is what it sees.
Clear impacts read better than buried ones. A gunshot with room around it is an easier call than one under a dense combat bed.
Only the strongest event drives the hardware. A well-separated impact carries over the surrounding bed. Dynamic range is what gives a hit its rise.
Speech and music produce nothing. Dialogue scenes stay quiet on their own, whatever low end the mix carries.
Speech carrying no haptic intensity is different from muting everything around it. An explosion during dialogue still produces output, because it is the stronger event.
Two consequences worth designing around:
- Dialogue-heavy sequences are handled automatically. No work is required on your side to keep haptics quiet during conversation.
- Music will not drive haptics through this path. Where music is the point, in a rhythm game or a set-piece built around the score, there are two routes. A curated Audio-to-Haptics profile can apply gain on specific frequency intervals so the track itself carries the haptics, or the WYVRN SDK can author them explicitly.
Response shape
The response is deliberately asymmetric. An impact arrives immediately, with no attack ramp, and its tail decays gradually rather than cutting off. A mix with dynamic range gives this envelope a clear rise to act on.
Silence behavior
While audio is silent, analysis does not run. After a few seconds of continuous silence, haptic output stops and resets. Output resumes as soon as audio returns.
Per-game haptic profiles
Sensa HD Haptics exposes four Audio-to-Haptics profiles in Synapse:
| Profile | Description |
|---|---|
| Controlled | Deep, bass-focused response. Rarely triggers haptics for voice, including in-game chat. |
| Balanced | General-purpose default |
| Dynamic | The most reactive preset |
| Custom | User-defined gains |
A profile can be associated with a specific game under Haptic Game Profiles, and loads automatically when that title takes the foreground.
Razer curates the default profile for listed titles. A player's own profile selection always overrides the curated default, so treat a curated profile as a starting point rather than a guarantee.
Developers cannot ship a profile directly. A Chroma Sensa title integrating the WYVRN SDK may have a game-specific profile defined, subject to approval with the developer and internal QA at Razer. Contact Razer through Razer Indie Lab or your developer relations contact to begin that process.
Next
- Screen Sync, the lighting path for games and video
- Performance, measured cost and latency