Question / Help The recorded sound is very low - very strange

Siopaulo

New Member
1. I have USB external profi sound card with mic preamp and levels go into the yellow field without gain ... good like on the picture:
Levels.png

2. But when I record the video with audio and play it in for example media player the sound level is very low even everything is set up to 100%.
What shall I do? ... it seems to me OBS is somehow dramatically reducing the sound level. Because other files has normal level ... Just the record from OBS is like you see on the picture.
Player.png


3. Finally, it is strange I can set up volume % more then 100 in the OBS Advanced audio properties. It is giving some significant gain but not nice ... a lot of noise.
Volume.png

Thank you for your help.
Paul
 

carlmmii

Active Member
Working as intended. The volume meter you see in the windows mixer is a linear volume scale. The volume meter in OBS is a logarithmic one. Decibels work on a logarithmic principle: +10db means 10x louder.

-10db on OBS's mixer (just under the top of the yellow region) is 10% of maximum volume. -20db is 1%. This means if you're keeping your audio levels in the yellow, then you should expect to see the green bar in windows' mixer to stay in the 1-10% range.

For your volume over 100% question, yeah, that's a thing you can do. But you're going to be limited by the original signal, and the clipping limits. You can't increase the signal volume past the maximum volume you're working with -- if you have an instance where the signal value exceeds this, it will be truncated to the maximum. This is known as clipping. If you need to increase volume past this, you'll need to experiment with compression to get closer to those limits without going into the clipping region.
 

Suslik V

Active Member
The Windows Media Player is not the best choice, probably you playing wrong track from video. Try VLC Player - there you can select the track you wish to playback.
 

Siopaulo

New Member
Working as intended. The volume meter you see in the windows mixer is a linear volume scale. The volume meter in OBS is a logarithmic one. Decibels work on a logarithmic principle: +10db means 10x louder.

-10db on OBS's mixer (just under the top of the yellow region) is 10% of maximum volume. -20db is 1%. This means if you're keeping your audio levels in the yellow, then you should expect to see the green bar in windows' mixer to stay in the 1-10% range.

For your volume over 100% question, yeah, that's a thing you can do. But you're going to be limited by the original signal, and the clipping limits. You can't increase the signal volume past the maximum volume you're working with -- if you have an instance where the signal value exceeds this, it will be truncated to the maximum. This is known as clipping. If you need to increase volume past this, you'll need to experiment with compression to get closer to those limits without going into the clipping region.

Thank you for the answer. It is much clear for me. If I go for volume over 100% I see that the meter is increasing as well. So I think I can increase as much as I will be close to 0 in red area but be safe enough not to reach the 0 to avoid clipping. Am I right?

If I play mp3 music in the media player then it goes easily to 100% ... I suppose that the mp3 is mastered product with a lot of maximizing and limiting the signal, that is why it seem to me low the OSB signal.
 

carlmmii

Active Member
Correct, raise as much as you want just as long as you never actually have clipping occur.

.mp3's are usually leveled to make maximum usage of the available volume. They're recorded at a certain 0db reference, but then after the fact they're compressed and normalized to make the most out of the amplitude range. Sometimes this isn't done, but for most situations this is a standard block in the process of mp3 conversion (and any time you have that option for "normalize levels" in whatever music player you use, that's what it's doing).

By contrast, OBS is a live recording tool. It can't ever know what your loudest possible volume is, so there's no way for you to ever have a known "this is my limit and I will never exceed it" type deal. That's why the general guideline is to stay in the yellow, allowing for a bit of creep into the red region for particularly loud sounds. That way clipping (which is actual data loss, not to mention sounds like crap) is unlikely to occur.

Compression/limiting can help you achieve a louder volume, but that comes with its own quirks and may not be desirable for what you want to record.
 
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