Comment 93 for bug 1654448

On Sat, Jul 1, 2017 at 1:11 AM, Esokrates <email address hidden> wrote:
> Kai: I do not understand your last comment, could you elaborate? Did you
> mean we should test if software boost = pulseaudio boost performs well
> enough?

Yes.

> Kai, I am quite happy with
> http://people.canonical.com/~khfeng/lp1654448-2/ please link me the
> patch as the only drawback would be the lower volume, right? :-).

Traditional microphone will lose hardware mic boost.
That said, software boost for mic should good enough.

> I will try to test the pulseaudio boost in the next days. Could you
> explain a bit of theory? What would you expect in terms of quality
> regarding the pulseaudio boost? Is there something special I should
> consider? What would be a good way to test for disortion?

There's no objective measurement. Use your own ear - if you think the
quality is good, then the quality is good.

>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1654448
>
> Title:
> XPS 13 9360 and 9350, Realtek ALC3246, Headphone audio hiss
>
> Status in Dell Sputnik:
> Confirmed
> Status in alsa-driver package in Ubuntu:
> Confirmed
> Status in linux package in Ubuntu:
> In Progress
> Status in pulseaudio package in Ubuntu:
> Confirmed
>
> Bug description:
> Pertaining to 16.04 on a dell XPS 13 9360
>
> ii alsa-base 1.0.25+dfsg-0ubuntu5
>
> Advanced Linux Sound Architecture Driver Version k4.4.0-57-generic.
>
>
> When headphones are plugged in, there is a clearly audible hiss (white noise). This is present as soon as the headphones are plugged in, whether 'headphones' or 'headset' are selected from the pop-up box.
>
> Using alsamixer to debug the issue reveals that it is related to
> "Headphone Mic Boost" - the default setting is: dB gain 0.00, 0.00. If
> this is changed to:
>
> 10.00, 10.00 (one notch up) the hiss disappears.
> 20.00, 20.00 cause a louder hiss and
> 30.00, 30.00 causes an even louder hiss with high frequency audio artifacts.
>
> When the headphones are removed and plugged back in the Headphone Mic
> Boost setting returns to dB gain 0 and the problem also returns.
>
> This (problem and workaround) has been reported in the wild:
> https://news.ycombinator.com/item?id=13050843 and
> https://www.reddit.com/r/Dell/comments/4j1zz4/headphones_have_static_noise_with_ubuntu_1604_on/
> for example
>
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