Explosion sounds

I already asked this but,

How do I make a sound be heard really far away? I'm using Detonator, and it's when a missile hits the ground. The missile is being shot from a plane, which keeps flying. I've tried adjusting all the settings, but nothing seems to work. Someone suggested parenting a gameobject that was closer to the player and emit the sound from there, but the player could be anywhere in relevance to the missile.

You could use 2D sounds and modify the volume depending on distance between player and hit point.

If the distance is too big set a minimum volume.