[mythtv-users] audio quality problems in mythtv

[Ken Truesdale]

For anyone else having the audio quality issues, where mythmusic doesn't
sound as good as other music players, here's what I did:  

 

First, I found a way for my receiver to put on screen the audio input info.
I discovered that aplay and vlc were both sending 5.1 audio but mythavtest
was sending only 2-channel audio.  Interesting but not the answer.  

 

Second, it turned out that mythavtest doesn't pay attention to the settings
in mythmusic.  At least not that I could tell.  So all of my monkeying
around in settings in mythmusic and then testing in mythavtest was useless.
I needed to test through the regular front end to get it to play through
mythmusic.  

 

Third, it turned out part of my problem was that my receiver, having had the
levels and frequencies set through one of those automatic programs with a
mic, was relying on the subwoofer to provide bass.  So when the receiver
plays something genuinely 2-channel and plays it without the sub, it won't
sound as good.  (Seems like I should be able to run the level setting
program for a 2-channel setup also and have it either use the sub for
2-channel or boost the bass of the main speaker pair - but that's an issue
with my receiver, not with MythTV.)  

 

Fourth, I had my Myth audio output device set to a "hw" which avoids the
software alterations because I thought that would produce the "purest"
sound.  But the "plughw" equivalent sounded way better.  Also, I left the
upconvert to 5.1 unselected in the Audio setup.  

 

In the Music Settings, I left audio device as "default" (actually, changing
here seemed to always lead to problems) but I did select convert stereo to
5.1 here.  

 

I'd still be interested in hearing (pun!) anyone else's opinions or
experiences.  Or for any experts, feel free to correct anything I have
incorrect.  Thanks!  

 

 

Ken.

 

 

From: Ken Truesdale
Sent: Tuesday, February 03, 2015 11:06 AM
To: Discussion about MythTV
Subject: audio quality problems in mythtv

 

I've been using MythTV for a while but only recently got the HDMI output
into a receiver with a good 5.1 speaker set up.  The sound is poor and is
particularly noticeable on audio (only) files.  (I think videos may be not
be perfect either but doing A/B comparisons is harder with video so I'll
stick to audio only files for testing for now.  

 

I have been able to simplify the testing by copying a single file from a
factory CD with no transcoding.  I play that file through VLC and it sounds
rich and full and the subwoofer booms nicely.  Ditto just using "aplay".
But using mythavtest produces a thin sound and the subwoofer makes no sound
at all.  I assume the sub's channel is still active but the output is so
weak, it doesn't end up with anything to do.  It's not quite like a clock
radio but too close to it for me to consider it usable for home
entertainment!  

 

I've been playing around with settings in the Audio section of Setup and
haven't been able to effect any change.  I've tried with upconvert to 5.1
and without it.  I've got all the Digital Audio Capabilities checkboxes
checked.  When I do the Test in the audio setup, I can confirm that all 6
speakers emit a test tone.  I haven't played around with any of the Advanced
Audio settings.  

 

There are lots of places that I could still look but I feel like I've
exhausted the obvious and I'm hoping somebody has a suggestion about the
smartest place to start looking from here.  I'm running MythTV 27 running on
Mythbuntu.  V0.27.3-152-g926bb8d.  Thanks!  

 

 

Ken.

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