I'm using a PVR-150 with KnoppMyth R5B7. I'm using the default audio settings. When watching live TV, the audio sounds distorted and tinny, kind of like when you take a small radio and crank the volume all the way up. Can anyone explain this? How can I make my audio sound perfect within MythTV? Any hints on how to troubleshoot this problem would be greatly appreciated! Thanks.

Go look at the settings for the "live" recording profile for that class of cards, and make sure that you don't have the volume at 100%. If you do, try backing it down to ~90% and see if that helps.

BTW - This has been covered a couple times recently. A search should turn up more details.

Audio levels are already set at 90%. After looking through 5 pages of search results, I found a post that helps. If I use the command 'ivtvctl -q 1' while watching live tv, the sound suddenly become normal again. After rebooting though, the poor sound is back. What is the permanent solution?

I can think of any number of ways to get this command run, but I think the right thing is probably to get a parameter set correctly so that the system does that for you. Look into what the /etc/init.d/set_ivtv_params script does, add an appropriate call and an appropriate setting in /etc/sysconfig/ivtv/cfg-0

BTW - Take a look around for other threads where this issue hasn't been resolved and let them know too...

Thanks for the advice. I just tried it, but unfortunately is does not help. As soon as you hit the watch live TV button, the audio is crappy. If I then run the command it is fine. If I exit live TV and then come back to live TV, the sound is messed up again. I'm going to post this question to the IVTV mailing list and report back.

Search for a thread discussing using ivtv-tune in an external tuning script as away to force corrective settings to take place. Putting my handle in the author box of the search should help to narrow it down.

Thanks for all of your suggestions TJC. I have found a work-around that works!
I configured muthtv to use an external channel changing script, and added the following line at the end:



So my full channel change script for the PVR-150 with IR blaster is:

I was able to get rid of my tinny audio / sound by rolling back to ivtv-0.4.1 and rebooting. I chose ivtv-0.4.1 because of the similar architecture (is that the right term?) to 0.4.3 thru 0.4.5. I've been using 0.4.1 for about 5 days now with no tinny audio or other issues. I'm running a clean install of R5B7. I found that the channel changing hack worked fairly well for live tv, but I only got tinny audio on recordings.

_________________
Mike
My Hardware Profile

has anyone else rolled back the version of IVTV? I would be interested to know what people thought of this idea.

/Stu

Probably not a viable option for the distro because too many new PVR cards wouldn't be supported. On the other hand as an individual user it makes perfect sense to go with the version that works best for you. A final caveat, if Cecil goes to one of the 2.6.16 linux kernels in a future release an ivtv 0.6.x or later will be required for compatibility...