How can I create an explosion?

I want to create an explosion sound effect in Audacity. I recorded the sound of a firecracker but it doesn’t sound like an explosion. I have tried to change the bass of the sound file and I made it slower, but then the sound always gets too quit. It sounds maybe like a silent explosion.
How can I create an explosion that is not too quiet?

Here is my Audacity file, it’s the original firecracker sound:

Silence the first 0.02 seconds (Command + L)
Fade in from 0.02 to the start of the actual sound (about 0.026 s).
Repeat the Fade-in a couple of times.
Fade out from about 0.18 seconds to the end of the track.
Select from the end of the track to 1.0 seconds and generate silence.
Select the entire track and apply the High-Pass filter, 100 Hz, 48 dB per octave.
Apply “Change Speed” and stretch the sound to 10 seconds.
Apply “Limiter”: Hard Limit, 0.0, 0.0, 0.0, 10.0, No.
Apply “Leveller” with Degrees of levelling: Heaviest
Trim to 3 seconds:

There is a plugin …

The track only lasts 0.26 seconds. Did you mean 0.01 seconds? Should I select 0.01s at the end of the track and then generate silence?

No, I mean “select from the end of the track (0.26 seconds) to 1.0 seconds” so that you have selected 0.76 seconds of “empty space”, then generate 0.76 seconds of silence into that empty space. This is just to give a bit of “padding” at the end. Working with very short sounds can be awkward for several reasons: Some sound cards don’t play right to the end of the track and some effects will produce glitches at the end of the track. Allowing a bit of padding, and then trimming down at the end is generally a good idea when working with very short sounds.

I have created the sound effect but there is an annoying noise somewhere at the beginning(0.25-0.45s) of the track. In your .flac file, there is no such noise. Did I something wrong? How can I avoid this annoying noise?
My file:

Could you export your version as a FLAC file please. The data folders are not transferring easily.

I made a new attempt and now it works. I don’t know what was wrong with my last track but know it works as expected and I don’t get this annoying noise :slight_smile: I have not trimmed the track because I don’t know if there should be some silence at the beginning(before the explosion) and at the end(after the explosion) of the track :question: Should there be any silence at the beginning and/or at the end of the track? If yes, how many seconds/milliseconds?
Here are my files(.flac file, video how I made it, Audacity files):

That depends on what you intend to do with it, and you’ve not told us that.

I create sound effects for my first mobile phone game. For example, if the player touches a bomb, the explosion sound effect should be played immediately(only once).
In addition, what is the best way to make a sound effect quieter or louder?

I’d imagine that for a game, you would want to trim off the leading and trailing silence, but you would probably also need to pre-load the audio into RAM so that it can be played straight away (rather than waiting for it to load). How to do that, and how to control the playback volume are beyond the scope of this forum. If you are using some kind of “game maker” software, then you will need to refer to its documentation.