are you using this for (e.g., YouTube video, presentation)? Do you need other sound effects to go with it?

Based on your request, I have identified the specific "Countdown-Boom" sound effect you are likely looking for and created a helpful guide for using it.

For maximum impact, layer this sound effect with a low-frequency rumble or a slight crescendo (gradual increase in volume) during the countdown numbers leading up to the boom.

Mixkit Countdown Sound Effects : Various styles, including clock bleeps and voices.