[pulseaudio-discuss] [RFC PATCH 0/6] LFE filter

[Alexander E. Patrakov]

06.02.2015 16:41, David Henningsson wrote:
>
>
> On 2015-02-04 18:45, Alexander E. Patrakov wrote:
>> Sorry for a possibly-stupid question, but...
>>
>> Which part of PulseAudio is supposed to disable the effect if the user
>> plugs headphones in? Or is it yet to be written?
>
> 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.
>
>

OK, so we are on the same page. Also don't forget about the existing 
virtual-surround sink, as it also exposes the fake LFE channel.

Because of the issues quoted above, I'd prefer not to make the LFE 
remixer the default, until a mechanism appears to associate the possible 
sound enhancements (such as: "on this port an LFE speaker exists, thus 
LFE remixing makes sense", and, in the future: "this ultimately leads to 
headphones, thus virtual-surround makes sense", "this has an impulse 
response measured, thus convolution with this set of wav files makes 
sense") with ports, persistently.

-- 
Alexander E. Patrakov