I want to increase the loudness

[programm]

I use an .mp3 in a game that allows you to import sounds. Since the music of that mp3 is too low as it is background for sound effects, I wanna make that .mp3 louder so that it is not so low and can be heard loud enough together with the sound effects of the game. Is there a filter or smth that increases the loudness of an mp3? I use Audacuty 1.3.7., OS: Windows XP Pro SP2.

[steve]

Have you tried the "Amplify" effect?

[programm]

I tried and when the window with Apmplify where you change the dB appears, I have to check the 'Allow clipping' box to be able to save it when I increase the dB. While it becomes louder, it also sounds bad - It's on intervals you can hear some bad crackle, the original file doesn't have that. So ways to do it without making the quality bad?


Since it is mono, can you pls telll me how to make it a stereo? Will duplicating it and changing its upper (main box) to be Left and the lower (duplicated) box to be right, not mono. Will this make it?

[steve]

"Clipping" is when the top and/or bottom of the waveform get chopped off - it is a nasty kind of distortion that occurs when you try to amplify a sound higher than 0dB. In digital audio, "0dB" is "full scale" - there is no way to increase a signal beyond 0dB. The actual numerical values of the individual samples are in the range of +1.0 to -1.0 and if you try to set a sample value to greater than +1.0, or less than -1.0 it will be truncated to + or - 1.0.

Audio can be made to sound louder by increasing the average signal level - this is a more musical kind of distortion and is achieved by using "dynamic compression". There are two main kinds of dynamic compression, one type (known just as "compression") works on relatively large sections of sound and smoothly increases the level of quieter sounds so that the average level is increased. The other type is called "limiting" and works on individual wave cycles, squashing the peaks to prevent them going over a set level. By squashing the peaks, the sound can then be amplified without going over 0dB, and again the average amplitude is increased, making it sound louder.

There are several plug-ins available for Audacity that will perform compression/limiting. My favourites are; "fast lookahead limiter" (I think this is included in the plug-in bundle available from the main Audacity website), and "Chris's Dynamic Compressor" (just Google for it).

[kozikowski]

<<<"Chris's Dynamic Compressor" >>>

This is a terrific compressor. I use it to process internet talk shows before I burn them to CD so I can listen in the car. If I don't do that, I have the same problem you do, They're very theatrical and flamboyant, but not very loud and they damage and get crunchy easily.

Koz