IDT/SigmaTel High Definition Audio CODEC - solution

I have been trying to figure out how to record sound from online videos for some time now on a laptop I recently acquired. The laptop is a Gateway T-1628, running Windows Vista SP2. It is reasonably powerful since I upgraded the RAM to 4GB. Unfortunately, it has a rather weak sound chip, which is an IDT/Sigmatel.
I found that it did not have the options that I needed from the sound chip to set Audacity 2.05 to be able to record sounds from other programs. I googled for a solution, and found that none of them worked in this case. I tried a variety of drivers, but none of them would even load properly except for the ones on the Gateway site for this model. The four registry keys that can be changed h to enable Stereo MIx have no effect. I wasn’t interested in the cable from mic to headphones. Since I was stuck with two input devices, Digital Mic and MIcrophone/Line In, I decided that I would just go through all of the input and output options of Audacity to see if I could figure something out. I might not have, but I noticed that I could select things for output that ought to be for input, and vice versa.
Before too long, I found out that if set to the settings below, Audacity worked just like you would expect.

Audio Host: Windows WASAPI
Output Device: Speakers/Headphones (SigmaTel High Definition Audio CODEC)
Input Device: Speakers/Headphones (SigmaTel High Definition Audio CODEC)
Audacity settings.jpg
I wouldn’t have guessed that, but I’m not going to argue with what works.
Maybe this will save someone some frustration.
Good luck.

If you read the Manual you would… . But I agree this feature is not all that discoverable if you don’t read the Manual. I don’t know what can be done about that, at least until WASAPI can be bug fixed so that it also supports mic and line inputs and can be made default.


You are absolutely right. I didn’t read the manual. I have been using various versions of Audacity for several years, so I assumed I didn’t need to RTFM.
However, when I did read the manual to see what I missed, I didn’t find it very clear. The main problem I saw was the repeated use of the term “loopback”. I know what a loopback interface is, since I have had electronics training courtesy of Uncle Sam, and have been working in IT for the last 20 years. I used to use loopback plugs (I made) to test serial and parallel ports back when people used them, and I am very familiar with the lo: ethernet interface in Linux. However, it seemed unclear because I almost never see that term used on Windows systems. The way the page read, it seemed as if maybe I should be seeing that somewhere.
I have seen a lot of hardware and software. My first PC sound card was an AdLib, which of course was no competition at all for my Amiga 500 on my other computer desk.
I feel that if it wasn’t clear to me, others who don’t have my background are more likely to have a problem understanding that section. I will volunteer to reword the section and the WASAPI section on if that would be helpful, as repayment for how often I have used Audacity at no cost. Seriously. I currently have some time on my hands.

This is the other key page in the Manual that talks about using WASAPI:

The tutorial it forms part of is linked to directly from the Front Page and should be discoverable by someone wha wants to do “Recording streaming audio playing on the computer”

This page is linked to directly from the Devices Preferences page - the blue link that says “recording computer playback” in the WASAPI entry.


“Loopback” is a Windows recording feature on Vista and later. We are using Microsoft’s own “Loopback” term: (just as in “loopback cable”).

Some applications call this “Windows Vista recording” or “Windows recording” rather than “loopback recording” but “(loopback)” is added to the device name by the WASAPI API as I understand it. It would need code changes to somehow present another term than loopback. It could probably be done in the tooltip but I doubt the developers will want to do that .

Thanks for offering to tweak the Manual. I’ve tweaked the introduction on the page for Recording Computer Playback on Windows so that WASAPI is mentioned. It now says:

  • On Windows XP and 2000, Audacity relies on your computer sound device providing an input for recording computer playback, typically called “Stereo Mix” or “What U Hear”. This input can be chosen in Audacity’s Device Toolbar. If there is no such input, you can use other methods such as a loopback cable as described below.
  • On Windows Vista, Windows 7 or Windows 8, sound devices often lack a “Stereo Mix” or similar input, or it must be specially enabled in the Windows “Sound” Control Panel. On these operating systems, you can also choose Windows WASAPI host and the “(loopback)” input choice in Device Toolbar. This will record computer playback even if the computer sound device lacks its own input to do this.

I don’t see that the text below the introduction can be improved much. But you can make a suggestion if you think it can be clarified.