From mboxrd@z Thu Jan 1 00:00:00 1970 From: Raymond Yau Subject: Re: Mixer volume/decibel mapping Date: Sat, 5 Jun 2010 07:46:17 +0800 Message-ID: References: <201005191834.57919.vand2@gmx.de> <4BF629B3.9020904@ladisch.de> <201005210951.36495.peter.ujfalusi@nokia.com> <4BF658C6.4030404@ladisch.de> <4BFB8C89.3010207@ladisch.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-gw0-f51.google.com (mail-gw0-f51.google.com [74.125.83.51]) by alsa0.perex.cz (Postfix) with ESMTP id DD9C6103B34 for ; Sat, 5 Jun 2010 01:46:18 +0200 (CEST) Received: by gwj15 with SMTP id 15so1370265gwj.38 for ; Fri, 04 Jun 2010 16:46:17 -0700 (PDT) In-Reply-To: <4BFB8C89.3010207@ladisch.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: ALSA Development Mailing List List-Id: alsa-devel@alsa-project.org 2010/5/25 Clemens Ladisch > Raymond Yau wrote: > > 2010/5/21 Clemens Ladisch > > > > > 0 == -infinity dB, full scale == 0 dB, and the mapping between mixer > > > control values and corresponding dB values it _not_ linear. > > > > 20 log10 rule This mean than 0.5 == -6 dB , 0.25 == -12 dB , 0.124 == -24dB . 0.625 == -48dB I have doubt why PA is at 15% when the volume control of HDA is -48dB