AC3 conversion lowers audio levels

[FreeBaGeL]

I have a bunch of mkv files that have AAC audio. I use plex media server on my roku and there's a known defect with it where the audio gets out of sync with AAC audio. So, I've been converting the AAC audio to AC3 however when I do that the max audio lower comes out much lower than it was before.

I've tried using WinFF and also tried demuxing the mkv, converting the audio track to AC3 using SuperC, and then remuxing it back into the mkv. Either way, I get the same result that my max audio level is about half of what it was before.

Is this a known side effect of converting to AC3? Is there any way around it?

[Delta2]

try to convert your mkv with mkv2ac3 using aften or eac3to and check the option Normalize, it will sound better I think

[Baldrick]

Or popcorn mkv audio converter.

[cal_tony]

To reset audio in my MKVs I use Vidcoder or XmediaRecode. Vidcoder has a box in the audio settings that allow you to set audio level from-20 to+20 DB. XmediaRecode has a setting box that allow for a % change. With that program I have used 250% as well as 500%. At 500% there is a dramatic increase in volume.

Tony

[hello_hello]

In theory there's no reason why the re-encoded audio should be any different to the original, volume-wise. It might be a playback issue rather than an encoding one.

Are you downmixing multichannel audio to stereo? If so there's a chance the way the audio is being downmixed is causing a volume drop.

The first question which comes to mind for me..... after you've demuxed the AAC audio and converted it to AC3 have you tried playing the two audio steams and comparing their volumes before re-muxing the AC3 audio back into the MKV? If so, is there a volume drop? If the volume is the same when playing the audio streams then it must be a (video player) playback issue. Obviously though, if they're not it's an encoding one.

[budwzr]

Try Audacity.