Using the built-in microphone on a Latitude D630 in Ubuntu Hardy

Just briefly (I’ll hopefully add some more about my new machine later):

The Intel HDA sound drivers that ship with Hardy work just fine on this machine, but if you don’t know what all the sliders do (I had absolutely no clue) you’ll have a hard time getting any signal from the built-in microphone.

After some fiddling I figured out that the Capture screen of alsamixer gives you access to the appropriate controls. You need to set one of the Input sources to “Front mic”, you need to up the Mux on that one a little, and you need to make sure that the channel says “Capture” below it (in red, leftmost column in the image below) – otherwise it’s actually muted.

Now if you want to know a little bit more on what all this is about: I found a few clues here. Apparently Mux controls something like an analog pre-gain for the AD-converter, and the different channels on display in the Capture menu reflect the fact that the Sigmatel chip offers multiple AD-converters.

You can verify the proper operation of the mic using arecord and aplay like so (where hw:0,0 refers to the channel I activated as shown in the screenshot):

arecord -f cd -D hw:0,0 -d 5 test.wav # now say something...
aplay test.wav

Another thing I have to point out is that I have no idea if this is a best practice to getting it working right. Ubuntu Hardy uses something called PulseAudio and I haven’t had time to educate myself as to where that fits into the whole audio stack. Should I not fiddle with things through ALSA anymore? There’s more reading on all the different audio components at but I haven’t had time to really get a clear picture of matters so far. Would love to hear from anyone who knows more about this.

In case the follow-up doesn’t come soon enough, do prod me if you need more info on the Latitude. One hint: if you’re ordering, phone them up and insist that you want Intel wifi (that’s not configurable in the webshop sometimes) and not the Broadcom stuff.


14 Responses to “Using the built-in microphone on a Latitude D630 in Ubuntu Hardy”

  1. 1 SnappyCrunch 3 November 2008 at 3:50

    Thanks! This is exactly what I needed to get my mic working in Intrepid Ibex! The only difference was that I had to run “alsamixer -Dhw” to get to the hardware mixers. If I just ran “alsamixer” it would only give me the Pulse Audio mixers. I’ve added this fix to the footnotes on the Latitude D630 page of the Ubuntu Laptop Testing Team wiki.

  2. 2 yungchin 3 November 2008 at 11:41

    Hi, thanks for that, and for updating the wiki! I’ve been meaning to do that but I thought I’d get around to more thoroughly testing the hardware on this machine before that. Actually everything works so well that I’ve just been using it and doing lots of work, without any need to think about other hardware issues at all….

    Would you say that the default settings (at which the mic seems to not be working) call for a bug report? I could imagine other users would conclude the device is not properly supported.

  3. 3 Tormod 7 November 2008 at 16:01

    Yes, please file a bug. Sound recording (and VOIP etc) should work out of the box without fiddling with obscure mixer programs and mixer channels. Unfortunately we’re not there yet.

    • 4 yungchin 2 April 2009 at 22:09

      Confession: I still haven’t followed up on your kindly provided pointer… I haven’t had a chance to reproduce the problem. I’ll make it up in the next dev cycle!!

  4. 5 August Pamplona 2 April 2009 at 21:46

    It wasn’t working with a default install but I had my front microphone working on Hardy Heron on a Dell D630. My hard drive crashed and I reinstalled with Intrepid. Now I have no clue what I did to get it to work the last time. Running “alsamixer -Dhw” (or other similar tools) might be good except that I do not get a “Front Mic” option.

    Any ideas?

    • 6 yungchin 2 April 2009 at 22:07

      If you don’t see your mic at all, then you probably have a different problem (are you sure you’re in alsamixer’s Capture screen, not the Playback screen?). All the sound stuff has been changing a lot between 8.04 and 8.10, and I’m still on 8.04, so I’m not sure I can say anything useful, sorry…

      I’m planning to try the waters with 9.04 one of these days though, and it seems there’s still a lot of work and testing to do on PulseAudio :)

      • 7 August Pamplona 2 April 2009 at 22:31

        It looks similar to your screenshot but one difference is that when I use the up and down arrows on the ‘Input Source’ items the only choices I get are ‘Line’ and ‘Mic’. That is, I get no ‘Front Mic’ choice. I also have an ‘IEC958’ item and no ‘Digital’ item.

        • 8 yungchin 2 April 2009 at 22:48

          Ok, that’s probably only a cosmetic problem then: IEC958 is the name of the digital signalling standard used.

          There are two input sources here, too, so that’s good (one being the built-in mic, the other is the line-in on the left of the machine). I guess the names are a bit random. One of those two is your mic, but it may not be the one named mic… so you need to try it for both I guess – that is, turning up the muxer and making sure you enable capture (as in the screenshot).

          Good luck!

  5. 9 August Pamplona 3 April 2009 at 14:16

    Now I feel foolish. The second capture channel needs to be muted (as shown in your screen capture). When this is done (I previously had both enabled), you magically get a ‘Front Mic’ option.

    It should work now!

    • 10 yungchin 3 April 2009 at 14:24

      Why would you feel foolish? That muting-requirement is very unintuitive. I guess most users would have long drawn the conclusion that the mic is not supported.

      We should file a bug report. I just don’t know how to write it so that it is useful, and to make it sound as something worth working on.

  6. 11 August Pamplona 6 April 2009 at 15:25

    It doesn’t work with Skype, anyway. I suspect that the sound quality is just too noisy (loud background hiss) for Skype to process.

    • 12 yungchin 6 April 2009 at 16:04

      For me the built-in microphone works quite well with both Skype and Ekiga – both have testing services where you can get your own voice played back to you, and that sounds fine here.

      I can look at my current settings when I get home tonight and post them, if that helps.

  7. 13 Scott 27 July 2009 at 22:33

    I’d like to see your settings… just loaded Ubuntu 8.04 LTS last night, most things including wireless work nicely out of the box, but no internal mic recording, and output sound level works after tweaking Sound Preferences a little (but sound is too quiet).

    I was resigned to not using the internal mic as I plan to attach audio recording hardware, but if I can get it to work for Skype, VoIP clients, etc. that would be nice :)

    • 14 yungchin 30 July 2009 at 6:46

      Hi! My settings are still mostly as in the screenshot above, but with the Mux pumped up to 75, and the Capture level all the way down (this gets auto-adjusted by Skype).

      In Skype settings, under Sound Devices, I have “HDA Intel (hw:Intel,0)” set as Sound In device, everything else at default. In Ekiga preferences, under Audio Devices, I’ve also selected “HDA Intel” as input device.

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