Re: Web Audio API DeciBel Full Scale

Thanks a lot for your help.

Michele Cipriani

Dropin CEO
www.dropin.fm

eMail: cipriani.ceo@dropin.fm
Phone: +39 3284551317

Twitter: @ciprianimich
LinkedIn: linkedin.com/in/ciprianimichele/





Il giorno 25/mar/2014, alle ore 17:08, Chris Wilson <cwilso@google.com> ha scritto:

> Hey Michele-  The answer I gave on StackOverflow (http://stackoverflow.com/questions/22604500/web-audio-api-working-with-decibels) is still appropriate; the nominative audio sample range in Web Audio is [-1,+1], so the "max level" is 1.  The "sample level" is the level of the audio - in order words, the actual value of the sample itself.
> 
> If you recorded a WAV file "at" -8dBfs, I presume you just mean that the maximum value in the all the samples is at -8db of FS - aka +0.107 or so.  Just playing it back should replicate those values.  If you wanted that file to be at full scale, you'd need to connect it through a gain that would amplify it to be 1 - i.e., with a gain.value around 9.3.  You don't usually want to run that close to full scale, though - you want some headroom in case you are adding effects, etc.
> 
> 
> On Tue, Mar 25, 2014 at 2:58 AM, Michele Cipriani <cipriani.ceo@dropin.fm> wrote:
> Hello everyone,
> i am working on dropin.fm (a cloud digital audio workstation), and i am in doubt how decibel full scale works in Web Audio API.
> 
> As i read on the Oreilly book about Web Audio Api http://chimera.labs.oreilly.com/books/1234000001552/ch03.html
> dBFS = 20 * log( [sample level] / [max level] )
> But what ’s max level and sample level in a Web Audio Api audio context? 
> 
> If i import as audio buffer a  wav recorder at -8dbfs, how can i get the same value in a web audio api app?
> 
> Thanks a lot
> Michele Cipriani
> 
> Dropin CEO
> www.dropin.fm
> 
> eMail: cipriani.ceo@dropin.fm
> Phone: +39 3284551317
> 
> Twitter: @ciprianimich
> LinkedIn: linkedin.com/in/ciprianimichele/
> 
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