From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gabriel M. Beddingfield" Subject: Re: Delay calculations for USB audio? Date: Fri, 28 Sep 2012 06:23:14 -0500 Message-ID: <506588A2.4070602@gmail.com> References: <5065834E.4010707@canonical.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ob0-f179.google.com (mail-ob0-f179.google.com [209.85.214.179]) by alsa0.perex.cz (Postfix) with ESMTP id EF8262616C4 for ; Fri, 28 Sep 2012 13:23:29 +0200 (CEST) Received: by obblz20 with SMTP id lz20so2767257obb.38 for ; Fri, 28 Sep 2012 04:23:29 -0700 (PDT) In-Reply-To: <5065834E.4010707@canonical.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org On 09/28/2012 06:00 AM, David Henningsson wrote: > (Oh, and btw, if you have an idea of the crackling/distorted USB audio, > let me know. I'm using a standard Logitech USB Headset, using > speaker-test -c 2 -D plughw:Headset -t sine -r 48000 > I can make the problem go away using any of these options: > * Booting a 3.2 kernel - I've tried 3.5, 3.6-rc7 and 3.2 > * Choosing the 44100 sample rate instead of the default of 48000 > * Selecting the outer USB port instead of the inner one. Yes, there > are two USB ports next to each other, and this only happens on one of > them. (!)) The last statement sounds like you're sharing a hub with another device that has reserved bandwidth. For example, a USB webcam will often do this. Audio will work for a while and then get pre-empted. Use 'lsusb -t' to view your USB layout. -gabriel