Web Audio API DeciBel Full Scale

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/