From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Henningsson Subject: Re: [RFC PATCH] Inverted internal mic Date: Tue, 28 Feb 2012 19:11:15 +0100 Message-ID: <4F4D18C3.1020700@canonical.com> References: <4F4C9714.1080307@canonical.com> <4F4CA438.90103@canonical.com> <4F4CD1AF.2050409@canonical.com> <4F4CE264.7040008@canonical.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from youngberry.canonical.com (youngberry.canonical.com [91.189.89.112]) by alsa0.perex.cz (Postfix) with ESMTP id 86C92103F5F for ; Tue, 28 Feb 2012 19:11:22 +0100 (CET) In-Reply-To: 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: Takashi Iwai Cc: ALSA Development Mailing List , kailang@realtek.com, 903853@bugs.launchpad.net List-Id: alsa-devel@alsa-project.org On 02/28/2012 04:20 PM, Takashi Iwai wrote: >> I'm talking about recording an internal mic in *stereo*, as I just wrote >> below. Or don't you agree that is a valid and probably fairly common use >> case? > > Well, when you record it in stereo, and play it back, then you hear > the sound without problem. That could definitely be questioned: depending on the distance between speakers when you're finally playing it back, you might lose bass frequencies [1]. (That said, I'm not sure how much bass these mics pick up anyway.) > The problem happens only when you sum the > left and right signals into mono. Thus, as long as the stream is > handled as stereo, it could be passed as is, although it's not > optimal. So the official recommendation is that summing left and right to make a mono signal, is to be considered an invalid operation? -- David Henningsson, Canonical Ltd. http://launchpad.net/~diwic [1] Or possibly get distorted sound in different ways, not sure.