[SOLVED] ALSA volume on Airplay

[MarcB]

Hi,

i just got moodeaudio running using a Raspberry 3 and Hifiberry Amp. So far everything works as expected   beside one bug.

I have to reduce the ALSA volume (~70%), because the output is far too loud.

When I connect via airplay and watching a youtube video everything is ok but when the next video starts, the volume jumps to 100%.

The volume control is set to "Software".

Any ideas?

[Tim Curtis]

IIRC the Hifiberry Amp product does not support a decibel scale for volume and this causes issues
https://github.com/mikebrady/shairport-s...iberry+amp
https://github.com/mikebrady/shairport-sync/issues/232

[MarcB]

Hmm, as far as i understand, that was the behaviour i had, when volume control isset to "Hardware": No sound vs. 100% volume, nothing between (= a lot of shocking moments ).

My only problem is, that the Alsa value changes to 100%. So I reformulate the question: Can I "freeze" the Alsa volume to 75%, so that it could not be changed anymore?

[Tim Curtis]

If it were me I'd just get an IQaudIO DigiAMP+ or an Allo Volt and avoid all these issues, however in the spirit of hacking you could try modifying the file below :-)

Code:

/var/local/www/commandw/spspost.sh

You will see where ALSA 0dB (100) volume is restored. Just change to 75 and see if that works.

I can't guarantee that this file won't be overwritten in some future moOde update or version tho...

-Tim

[MarcB]

Thanks a lot, that worked.

I promise, I will update with care

[Tim Curtis]

Glad to hear that :-)

Please update your OP and mark it as SOLVED.

-Tim

[MarcB]

The same issue when connecting/unconnecting bluetooth (alsa volume jumps to 100).

I changed all "set-alsavol" in different *.php files to my maxvalue and it works.

I switched from volumio for reasons, but as far as I remember there was a defined "max alsa value", which is very useful in my case. Perhaps this is small improvement for future releases?

[Tim Curtis]

There certainly could be a global setting for max ALSA volume but it would take a non-trivial amount of work to implement and its only purpose, it would seem, would be to work around an issue in a single audio device i.e. the Hifiberry AMP.

it would be a different story if there were a lot of audio devices that did not implement a decibel volume scale but to my knowledge the Hifiberry AMP is the only one...

-Tim

[MarcB]

No problem, its a five minute job to go through all the files and change the values.

The rest works really well oob.

[Tim Curtis]

Cool. Just a heads up that in 4.4 vol.sh and all the scripts that call vol.sh will prefer GNU standard command syntax i.e., the options are prefixed with a dash "-" for example -up 2 instead of up 2. Vol.sh also will support --help and --version. The scripts including vol.sh will still be able to use the existing non-dash OPTIONS for the foreseeable future to maintain backward compatibility.

-Tim