[pulseaudio-discuss] Profile switching on headphone plugging (was: LFE filter)

Alexander E. Patrakov patrakov at gmail.com
Fri Feb 6 05:35:52 PST 2015

06.02.2015 16:41, David Henningsson wrote:

> Hrm, that is actually a good question. In theory, I would expect
> module-switch-on-port-available to switch profiles between 2.0 and 2.1
> as headphones are plugged in and out, but in practice,
>   - I'm not 100% sure if our "don't switch to HDMI" might prevent
> switching from 2.1 to 2.0 when headphones are plugged in, and
>   - As the 2.0 profile is available on speakers, that will continue to
> be selected when headphones are unplugged.
> So, while this is not directly related to whether there is an LFE filter
> or not - we already have a 2.1, 5.1, etc, profiles - indeed the problem
> might become worse with the LFE filter.

Well, I have just tested how today's git version of pulseaudio (without 
your patch) behaves when plugging headphones. Yes - the problem is 

The PC under test has analog outputs on the back panel that, 
theoretically, can be used as analog 5.1 outputs, and also has headphone 
and microphone sockets at the front panel.

So, the test is:

1. Make sure something (I tested with a cable extender) is plugged in 
the line output on the back panel.
2. Select the "analog stereo duplex" profile in pavucontrol.
3. Look at the Playback devices tab. It should say: Port: Line Out 
(plugged in).
4. Plug in headphones at the front. Note that the port changes to: 
Headphones (plugged in). I.e. exactly as expected.
5. Unplug the headphones, watch how the port changes back to Line Out 
(plugged in).
5. Now select the Analog Surround 5.1 + Stereo Input as a profile. Now 
the port stays as Line Out (plugged in), but the volume control becomes 
6. Plug headphones in. Result: the port stays as Line Out (plugged in), 
with 6-channel volume control, and speaker-test -c6 does not reach 

Sorry, I cannot retest this at home without additional jack-retasking 
(which could make the result untrustworthy), because my home PC does not 
have any audio sockets at the front panel.

Alexander E. Patrakov

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