LinuxQuestions.org
Welcome to the most active Linux Forum on the web.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Software
User Name
Password
Linux - Software This forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.

Notices


Reply
  Search this Thread
Old 11-09-2016, 06:58 AM   #1
BW-userx
LQ Guru
 
Registered: Sep 2013
Location: Somewhere in my head.
Distribution: Slackware (current), FreeBSD, Win10, It varies
Posts: 9,952

Rep: Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148
Understanding simple dB notation


what is the different between -5db and +5db? to me the hyphen is a minus and the plus is just that adding to, as I have in my possession ffmpeg-normalizer and it states this dB.

Quote:
-l --level <level> dB level to normalize to [default: -26]
the default is -26db, so am I right in thinking that it lowers everything to a negative -26dB which is illogical to me. makes everything so quiet you can't hear it?

if 26dB is the level which it is set to, and not (minus) -26dB then at what volume setting will one actually hear the 26dB level, 10%, 20% 30% 50% ... etc? also, if indeed it is just set to 26dB then why put a minus sign to the left of it?

if it is in fact a negative 26dB then one would have to raise the volume up to 100% plus to hear it, yes?

as apposed to mp3gain when increasing dB one should put +5 ???

that hyphen or negative mark is confusing me. Google is not helping I cannot find anything on that part of it to explain that to me.

Last edited by BW-userx; 11-09-2016 at 07:00 AM.
 
Old 11-09-2016, 07:28 AM   #2
michaelk
Moderator
 
Registered: Aug 2002
Posts: 21,599

Rep: Reputation: 4165Reputation: 4165Reputation: 4165Reputation: 4165Reputation: 4165Reputation: 4165Reputation: 4165Reputation: 4165Reputation: 4165Reputation: 4165Reputation: 4165
In a nutshell db is a relative number and assuming that ffmpeg uses dbFS the loudest output is referenced to 0 dB. Anything less the full scale is a negative number.

https://en.wikipedia.org/wiki/DBFS
 
Old 11-09-2016, 07:39 AM   #3
BW-userx
LQ Guru
 
Registered: Sep 2013
Location: Somewhere in my head.
Distribution: Slackware (current), FreeBSD, Win10, It varies
Posts: 9,952

Original Poster
Rep: Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148Reputation: 2148
Quote:
Originally Posted by michaelk View Post
In a nutshell db is a relative number and assuming that ffmpeg uses dbFS the loudest output is referenced to 0 dB. Anything less the full scale is a negative number.

https://en.wikipedia.org/wiki/DBFS
so at first glance of your explanation. ffmpeg scale is more like this
Quote:
normal shit
0 - 100
where 100 is what the self appointed collective has decided that is loud enough for human consumption. then ffmpeg decided to go against the collective, maybe from listing to too much rage against the machine and changed it to this,
-100 - 0
where zero is actually 100 percent of a given scale due to it being like infinity. You can always add one to whatever it is making it bigger, or louder.

so -26dB is around 26% of 100% volume actually.

thank you.

Last edited by BW-userx; 11-09-2016 at 07:45 AM.
 
Old 11-11-2016, 07:43 AM   #4
claytonjohnroby
LQ Newbie
 
Registered: Oct 2006
Posts: 23

Rep: Reputation: 0
Decibels is a logarithmic scale

Decibels is a logarithmic scale.

Like:

10^1=10
10^0=1
10^(-1)=0.1

Funnily enough humans hear sounds with ~10 times the energy as a noise that is twice as loud.

Hence the deci in decibel.

A dB of -1 is ~ half as loud as a dB of 0 and has about 1/10 th the energy.
 
  


Reply

Tags
sound, volume


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Help understanding Linux command synopsis notation. AlexTee Linux - Newbie 8 02-01-2011 11:43 AM
Simple BASH script; understanding loops and case Sinensis Linux - Newbie 1 06-17-2010 04:32 AM
Practical Assembly: Help Understanding gcc -S for simple.c? jhwilliams Programming 2 11-30-2009 05:30 PM
Understanding CIDR notation for iptables Madone_SL_5.5 Linux - Networking 5 12-07-2007 10:26 AM
pointer notation vs array notation? pablowablo Programming 5 03-14-2005 12:34 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Software

All times are GMT -5. The time now is 05:07 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration