Low volume (half?) with AC3

[InterClaw]

Hi, I'm having rather low volume when the sound codec is AC3 (a52). I see no a52-specific settings in preferences so I was wondering if there is a way to change this.

I remember back when I used BSPlayer that the AC3-codec had to be installed manually and that within the settings of that codec the master volume slider was set to 50% by default. Raising it to max (100%) solved the difference in volume completely compared to regular MP3 sound in other movies.

BTW, I'm not using S/PDIF output since I get weird stuttering in the sound (using a Yamaha V640 the regular Realtek AC'97 crap).

[InterClaw]

Just thought I'd bump this thread since it's been a while now.

Is bumping allowed?

EDIT: Well what do you know... Registered exactly a year ago today.

[Guest]

There is no specific settings for this. But you are correct when comparing MP3s that have little to no dynamic range to ac3 that has lots of dynamic range the average volume will appear lower using ac3. The only provision within the ac3 specification was dynamic range compression and the switch may be found in Preferences --> Input / Codecs --> Audio codecs --> A/52 try "A/52 dynamic range compression" both ways and see what works for you. It will never compare to MP3 though. For me I hate the distortion of the compressor so I shut it off. But this has nothing to do with VLC per say, as I shut it off in every program as I recognize it immediately.

VLC does provide boosting the gain to the input to your sound card, a feature not found on many other players. Raising the level beyond 50% is a boost. But beware, loud passages can distort the input of the audio card.

There is one other feature in VLC that some users have found useful. This is the Volume normalizer. Preferences -> Audio --> Filters check the box marked "Volume normalizer" Then press Save and close the player. The next time the player is opened the changes will take effect. This option will make VLC kinda sound like every other player, less dynamic range.

[InterClaw]

Thanks for your tips! I have another question then though:

Does a52 playback using S/PDIF (which I'm using now without problems, dunno what I did wrong before) always result in missing out on certain sounds on a stereo speaker setup (i.e. sound for middle and surround channels not being played at all in any speaker)?

The receiver is set up as A+B stereo so shouldn't the PCM signal be remixed into 2 channels? Or maybe it isn't and that's why the volume appears as low...? It's not THAT low, only I set the volume to like -46dB when watching a movie with a52 and only like -60dB when watching one with MP3 sound (probably encoded with HybridGain).

[Guest]

Think of A/52 as ac3 and DCA as DTS so the answer is yes.

Most DVDs offer stereo ac3 or in the menus 5.1 optional. If you have not selected the option the switch on your receiver will do nothing.