Greetings all,

I would very much like to be able to limit the loudness sound produced on my by my PC.

Let me set the scene: I am watching to a film on my PC , but can't hear the dialogue; I have to turn it up, then BOOM, a loud explosion and my ears are whacked. Or if I am listening to a film/browsing late at night, again I want the better clarity that comes with a louder volume, but not to wake others up with explosions or shouting.

If I had some volume limiting solution, then the actual noise produced by the program I am running does not go above a certain level. If the limit is set at e.g. 24 decibels, and the sound produced is -36db, then it comes out of my sound card at -24db, like that. (But if softer than -24db, then it still comes out at that original volume)

I have done much googling, but no definitive solution has arisen; here are some of the interesting pages I have found thus far:

http://brainstorm.ubuntu.com/idea/7073/
-the idea is suggested that an audio compressor is used.

http://www.mail-archive.com/pulseaud.../msg02447.html
- "You could use LADSPA to insert a limiter or compressor between the sound source and the output." This seems a little heavy on the programming/scripting side - don't get me wrong, I do want to learn more linux, but this just seems way above my head at the moment. If someone was willing to give a little guidance I may be willing to take this route though.

http://ubuntuforums.org/showthread.php?p=7700173
- suggestion on how to limit the master volume (I think), but I'm not sure if this thread quite details what I am looking for......

I am using ubuntu Jaunty with pulse audio, and I am wondering if it is possible to use this sound system to achieve my aims (as suggested in the above url or otherwise), or whether alsa is better, or what? As you can tell, I don't know too much about it.

Some final points:

Please don't tell me to buy better quality speakers/headphones

I am willing to sacrifice sound quality (although the less, the better)

"Normalizing" the volume would also be a fine solution (basically limiting the whole range of volumes that can be produced, between set levels)

I can (and do) use speakers or headphones


Thank you for reading (not too long I hope), and all help is much appreciated,

Ty

It is a dynamic range compressor you require on the audio (not to be confused with compression).

There are some compressor plugins around. An example is vlevel, though I'm not sure which player applications will be able to use it (perhaps gstreamer).

There is also the jack audio system, which allows lots of different audio applications to be linked together, including various effects processors. Probably a bit high-end for what you want.

Some of the players have inbuilt features. For example, mplayer is able to make use of the dynamic range control in AAC streams:
mplayer -a52drc 1 file.vob

Another option is to force clipping of the range in mplayer. You set a volume increase (eg 20db, and selecting the softclipping method :1), eg
mplayer -af volume=20:1 file.avi
which will force everything to be louder (so you need to turn down the main volume), and means that really loud stuff will clip. However, the quality of the loud sounds will be shocking, even with the soft clipping option.