How do I make a shuriken particle system sub-emitter only emit after collision with a certain velocity?

In a shuriken particle system ("parent system"), you can set a sub-emitter ("child system") to emit whenever a particle of the parent hits something. But it emits on every collision. What I'd like to do, is only have the child system emit when a particle from the parent hits a collider with a certain velocity.

Example: Only when a particle bullet hits a metal surface at a high enough velocity, a spark should appear. When a bullet has lost most of it's velocity after one or several impacts, it shouldn't cause sparks anymore. (For those that would say that bullets hitting metal shouldn't cause sparks: splinters when hitting wood.)

Is this possible, using only the Inspector option (without additional code), and if so, how?