On Sat, 3 May 2014, Antonis Kouzoupis wrote: > On Sat, May 03, 2014 at 09:14:34AM -0700, Bill Unruh wrote: >> I always thought that was hardware, not software. Ie, the headphone plugin >> contains a little switch which diverts the sound. But I could be wrong. Have >> you had that same laptop actually work as you want with some other >> distribution/operating system? > > This laptop comes with Ubuntu from factory, I think with some changes to the kernel, > and it worked well so I don't think it's a hardware issue. To mention that > Ubuntu adds ``options snd-hda-intel model=dell-headset-multi,dell-headset-multi'' > to /etc/modprobe.d/alsa-base.conf which I use too. > That does not mean that the switchoff of the internal speaker when the headphones are plugged in is not hardware. Some systems have, in the physical headphone plugin, a little switch which opens when the headphones are plugged in and which stops the current flowing to the internal speaker. Some hae a software switch which senses when current is flowing to the headphones, and sends back a signal to the sound card which then in software stops the headphones. The latter could in principle be controlled by alsa, the former could not. Such harware switches are common on amplifiers as well-- the assumption being tht if you are listening to headphones, you clearly do not want to also be listening to speakers as well. This also allow the volume knob to control both, since if both were on, when the speakers were at a comfortable level, the headphones could well be too loud. ------------------------------------------------------------------------------ "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available. Simple to use. Nothing to install. Get started now for free." http://p.sf.net/sfu/SauceLabs _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
