Maybe I was too vague. Stuff exploding in space consists of matter actually. Vacuum doesn't explode you know. Now if the object that explodes contains gas (and during an explosion/stuff being exposed to great heat certain meterials turn into gaseous form which explosively rushes outward due to the pressure difference between the two media, and in the sci-fi case some fusion reactor or plasma thingy loosing containment resulting in the same, thus creating a shockwave, though rather small due to the relatively low mass of these objects/stuff. If this one hits whatever you are situated in at the moment this object will vabrate and you'd either hear or feel the vibration of strong enough.