Meaning of negative dB -Sound Forge - PC - MAGIX Community Forums Archive

Subject:Meaning of negative dB Posted by: G100 Date:5/26/2002 10:04:34 PM What does it mean to normalize to a negative dB (-6dB)? Thanks
Subject:RE: Meaning of negative dB Reply by: Edin Date:5/27/2002 7:15:17 AM It means to have the highest peaks in an audio file going to the maximum level of -6dB. 0db in audio equipment means that output level is equal to the input level. Every 6dB means a doubling in volume or power of sound. Negative sign means that the output will be at lower level than the input. -6dB means that ouptut is twice quieter than the input, or that its level is twice lower (whichever you understand easier). In digital audio file, "normalization" to -6dB means that the highest peaks will be adjusted to reach the maximum of -6dB. For example, if your audio file contained peaks reaching up to -1dB, the volume or level of your whole audio file will be lowered by 5dB, so that the peaks are at -6dB. If your highest peak(s) was at -12dB, the volume of your audio file will be raised by 6dB, so that the peak(s) is at -6dB. But there is one thing you should know as well: in digital recording, 0dB is the maximum level to which a signal can go. Above that, the signal is going to be "clipped", or have its top "cut off". So, you should never cross the 0dB limit if you work on digital audio files. Always have at least 0.1dB below 0dB, which is -0.1dB. I usually "normalize" my files to -0.5dB (~95%), as it is recommended level for encoding to some "lossy" audio compression formats, like Windows Media Audio, Real Audio, MP3, etc. Also, you should always try to have either 0.5 or 1 second of silence inserted at the start and the end of an audio file. These changes will make basically no difference to anybody's ears, but will represent a huge improvement in quality of the compressed audio. I hope I was clear enough!
Subject:RE: Meaning of negative dB Reply by: G100 Date:5/27/2002 11:21:36 AM Thank you Edwin. I only had one explanation, but yours was good enough to clear up my understanding of dB levels. G100

It means to have the highest peaks in an audio file going to the maximum level of -6dB. 0db in audio equipment means that output level is equal to the input level.
Every 6dB means a doubling in volume or power of sound. Negative sign means that the output will be at lower level than the input. -6dB means that ouptut is twice quieter than the input, or that its level is twice lower (whichever you understand easier).
In digital audio file, "normalization" to -6dB means that the highest peaks will be adjusted to reach the maximum of -6dB. For example, if your audio file contained peaks reaching up to -1dB, the volume or level of your whole audio file will be lowered by 5dB, so that the peaks are at -6dB. If your highest peak(s) was at -12dB, the volume of your audio file will be raised by 6dB, so that the peak(s) is at -6dB.
But there is one thing you should know as well:
in digital recording, 0dB is the maximum level to which a signal can go. Above that, the signal is going to be "clipped", or have its top "cut off". So, you should never cross the 0dB limit if you work on digital audio files. Always have at least 0.1dB below 0dB, which is -0.1dB. I usually "normalize" my files to -0.5dB (~95%), as it is recommended level for encoding to some "lossy" audio compression formats, like Windows Media Audio, Real Audio, MP3, etc. Also, you should always try to have either 0.5 or 1 second of silence inserted at the start and the end of an audio file.
These changes will make basically no difference to anybody's ears, but will represent a huge improvement in quality of the compressed audio.

I hope I was clear enough!