From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rene Herman Subject: Re: What does 0dB refer to? (Logitech USB Speakers) Date: Thu, 17 Apr 2008 23:30:39 +0200 Message-ID: <4807C17F.8030603@keyaccess.nl> References: <20080411204610.GA32413@tango.0pointer.de> <20080414172839.GA26513@tango.0pointer.de> <4803C78A.3020109@superbug.co.uk> <200804150552.13578.faber@faberman.de> <20080415131203.GA2818@localhost> <4804BCB8.9060707@keyaccess.nl> <48060D2F.2000701@keyaccess.nl> <480618F3.40707@keyaccess.nl> <48061D1F.6060809@keyaccess.nl> <4807B569.6000008@superbug.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtpq2.groni1.gr.home.nl (smtpq2.groni1.gr.home.nl [213.51.130.201]) by alsa0.perex.cz (Postfix) with ESMTP id 2A50C24450 for ; Thu, 17 Apr 2008 23:27:38 +0200 (CEST) In-Reply-To: <4807B569.6000008@superbug.co.uk> 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: James Courtier-Dutton Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org On 17-04-08 22:39, James Courtier-Dutton wrote: [ John: I never drop CCs unrequested as I really dislike it when people do that in a conversation I myself am reading but please say so if you don't care to be in this thread ] > Rene Herman wrote: >> On 16-04-08 17:19, Rene Herman wrote: >> >> For now last time that I reply to myself (promise): >> >>> On 16-04-08 16:29, Rene Herman wrote: >>> >>>> On 15-04-08 16:33, Rene Herman wrote: >> >>>> On that note, I just acquired an Audigy 2 (SB0240) that I'm testing >>>> with and now that I'm paying attention to it due to this thread -- >>>> its 0 dB setting is very significantly louder (with everything >>>> behind the line-out constant ofcourse) than the 0 dB setting on my >>>> TerraTec DMX. >>>> >>>> James, I believe you are the emu10k1 person? Data: >>>> >>>> TerraTec DMX = ESS Canyon3D (ES1970MS-3D) + Sigmatel STAC9704T >>>> >>>> Creative Audigy 2 (SB0240) = Creative CA0102-ICT + Sigmatel >>>> STAC9721T (+ Crystal CS4382-KQ which seems to provide digital >>>> attenuation as well) >>>> >>>> At 0 dB master the Audigy 2 is much louder than the DMX is and >>>> audibly distorts. Judging by hearing, keeping the master at -16 dB >>>> (60 in the integer scale) gets things about the same. Was that scale >>>> provided by datasheet or just guessed? Especially the distortion >>>> would seem to indicate that something is actually doing analogue >>>> amplification at the 0 dB ALSA setting... >>> >>> Expanding, with the 'Line' control at 0 dB (74 integer) and 'Analog >>> Mix' at 0 dB (100 integer) everything does sound right with both >>> 'Master Capture' and 'Master' at full, and too faint with 'Master' >>> at -16 dB. I guess this indicates that it's something at the DSP side >>> only? (sort of loosing my way in this bewildering array of controls >>> so if I need to be guided to possibly say sensible things -- please do) >> >> When I do actually capture, -16 dB master is again the correct setting >> when playing back (with everything else still set to 0 dB as described >> above). It's then equally load as when directly monitored during >> recording. I expect then the Master dB scale needs to be adjusted >> down? If yes, I'll try to make very, very sure that -16 dB now is the >> correct new 0 dB. > > Can we narrow this down a bit please. > Run speaker-test -c2 -twav > Do the test to each sound card with alsamixer set to 0dB for most > controls accept the master, and leave the master at a sensible setting > for your setup so that you can hear sound at a sensible level > With the same dB values on the Andigy 2 and DMX, do you get the same > loudness of sound output to the speakers? Very much not. Sorry, it seems the report (unsnipped above) got a little confusing due to the followups but with everything at 0 dB on both DMX and Audigy 2, the Audigy 2 is much louder and distorts. DMX has 'PCM' -34.5 --> +12 dB and 'Master' -46.5 --> 0 dB. I always keep both at 0 dB for a good, comfortable level (adjusted further externally). Audigy 2 'Front' and 'Wave' are both at 0 dB (max) (everything default in fact) and with 'Master' at 0 dB, it's much louder then the DMX. Setting 'Master' to -16 dB (60) gets things the same. > I would like to find out if the problem is in the playback path, or the > capture path. Playback I'd say and I personally consider DMX right here, due to the distortion from the Audigy. Only introduced capture into the story above as "additional evidence" where I could do a a comparison using only the Audigy itself and not the DMX: with everything at 0 dB in the capture direction, a captured file needs to be played back at -16 dB 'Master' to be equally loud to what I hear _during_ capturing as well ("hear" from 'Analog Mix' at 0 dB). So I get the feeling it's a simple matter of transposing 0 dB on the Master scale for the Audigy (ie, new 0 dB is old -16 dB). I should have another emu10k1 driven card here somewhere. Is it useful if I try to dig it up and see if the story's the same on it? Rene.