Strange audio reception

[helpful55]

I am having one of the stranger problems I have ever had. I set up my OTA tv with Windows Media Center and a AverMedia USB tuner. At first I had a weak signal and cut outs. I got the antenna higher and got to where I got a good signal on nearly all of the main local channels. Possibly some at first but especially later on I started getting very strange audio but with no video problems at all. When I would click on a channel the main audio (say the commentators on a sports event or the host on a talk show) would be very weak yet the secondary audio like the on field sounds or the laugh track were normal level. The commercials were nearly always fine. This was all pretty intermittent. I might be able to go to another channel or back and forth and it would work, but usually not. A channel may be working fine but starting a recording may kill it. I thought maybe some kind of wmc fault or the tuner fault, but this continued when I set up NextPVR to use it. Even going to a Hauppauge pci tuner has the same problem. I have added an antenna signal booster which shows up a stronger signal in wmc tests and added a couple channels and although with a perfect picture with never any hiccups I still have the audio problem. I had contacted a local tv station and they did say that there is different audio on some programming so it could possibly be one of the stereo channel being the problem. I use my pc and sound system for many other uses and it does not nor has it ever had any kind of similar problem at all. Any ideas on this or where else I can ask?

Edit: I have been trying this setup on and off today and it has worked fine all day. I am not fully comfortable that this will continue though so I'd still like any ideas if possible. I am hoping this went away somehow, but we'll see.

[gEd]

When I would click on a channel the main audio (say the commentators on a sports event or the host on a talk show) would be very weak yet the secondary audio like the on field sounds or the laugh track were normal level.

This sounds like a problem downmixing 5.1 to stereo whereby the center channel is not being mixed correctly. Depending on what audio decoder you are using, you should be able to run nextpvr in window mode and bring up the audio decoder tray icon to inspect the properties of the audio stream to check this. Most audio decoders give you some control over the downmix to stereo.

Mine isn't perfect. There is a new David Attenborough nature program that is in 5,1 and I had to crank up the volume to hear the commentary correctly. I need to increase the center channel volume relative to the side channels.

[helpful55]

Well poop the problem is back, and when I checked the forum I got to trying your idea. I can click on the box to the right of the audio decoder selections and that opens a properties box. Full of stuff, most I don’t understand and I am careful to go back on anything I mess with and most of it I’d rather not! I have tried different decoders also and no help there. Yes your right I think typical voices like commentary or dialogue would be mainly on that center speaker channel and that is what I am missing. Sometimes it is at a very low level, sometimes totally gone.

I think your ideas here have helped me find something about this, but I need some more info so I can understand and fix this. When I right click and on that menu I can go to the settings that come up at the “Audio stream” arrow. What I am mostly seeing is Disabled, eng and spa or another eng option. I have tried clicking around on the eng and spa options and it allows the full audio! So this must be it, but the problem is that going to another channel requires going through that again. It doesn’t save the proper settings for each specific channel. It appears that what always works is the last option, but it is going back to the second option. I also see that it seems for commercials I have to set it to the first of the two options. I need to find out how to keep them set right or fix what is going wrong here. Maybe there is some way to delete that one option that it keeps defaulting to. If I hit disabled it will turn it off, but what does eng and spa refer to?

I suppose if this is specifically the decoder somehow I probably need to get to the decoder builder about those settings if that is it although this seems to be a Next program thing. I would think the developer would know what is going on here.

Unfortunately this doesn’t have anything to do with Windows Media Center so I don’t know why that also has these kind of problems. Know of any settings there? I can’t find any. Maybe that is some kind of decoder Windows uses. I have renewed WMC and still the same and that also happens with my laptop the same so it is unlikely to be a specific pc.

Thanks for any help.

[dixxfixx]

I suspect that "eng" and "spa" mean "English" and "Spanish". But I could be wrong.

[helpful55]

I suspect that "eng" and "spa" mean "English" and "Spanish". But I could be wrong.

I just came back here to mention that when I thought about it a little and you had the same thought. A little more knowledge. Thanks

[gEd]

When I right click and on that menu I can go to the settings that come up at the “Audio stream” arrow.

I meant run nextpvr in a window and when you start playback (depending on your audio decoder) you should see an decoder icon appear in the windows tool tray that you can then open to adjust the audio settings on the fly.

I'm not sure what the best audio decoder is for you as your TV standards are different to mine but I think US users often use the AC3filter. see post #18 here

http://forums.nextpvr.com/showthread.php...=ac3filter

the ac3filter decoder allows you to configure the 5.1 > stereo downmixing.

[mvallevand]

For AC3 I use the Microsoft DTV DVS Audio Decoder or LAV. The nice thing about LAV over AC3Filter is it handles more audio formats. I live in Canada not the US but we use the same standards.

Martin

[helpful55]

I meant run nextpvr in a window and when you start playback (depending on your audio decoder) you should see an decoder icon appear in the windows tool tray that you can then open to adjust the audio settings on the fly.

I'm not sure what the best audio decoder is for you as your TV standards are different to mine but I think US users often use the AC3filter. see post #18 here

http://forums.nextpvr.com/showthread.php...=ac3filter

the ac3filter decoder allows you to configure the 5.1 > stereo downmixing.

I’m actually not getting any decoder icon, what I am doing is going settings>decoders and clicking for the decoder properties box there. It has tabs for many different settings. This must be the same place you are wanting me to get to.

With the LAV decoder under the mixer tab there are sliders for Center, Surround and LFE. There also was a box to click for enable mixing which I clicked. Nothing I tried in changing those three levels helped, mostly made it worse. With the AC3filter decoder under the mixer tab I get sliders for Voice, Surround and LFE. Similar, any changes I make there do not help. Do you know exactly what to modify if I am not doing the right thing?

On my regular right click menu for Audio Stream I have these three selections: Disabled, eng and either another eng or spa. I continue to have to click to that third option as it defaults to the second (eng) and that always or nearly always has the missing audio portion problem. I have a beautiful picture (and sound when I click over), and a great recorder but it also defaults to the defective audio so those recordings are useless. I thought that somehow the decoder settings was the problem, but it sure seems to me that there is something haywire with the way that Audio Stream setting is working or allowing in the selection. I had wondered if somehow I was not getting all of the audio from my antenna, but it seems to all be there, it is just not coming through some part of the system. I wish the developer would weigh in as it doesn’t seem to be the decoders. I haven’t messed with any other settings anywhere that might have caused this. Thanks for any help here.

[mikeh49]

Try this to get AC3Filter working:

This assumes you are using the stereo analog audio output of the NPVR computer. If this isn't the case, you'll have to better explain your setup.

In your Windows start menu, you should have a program group for AC3 Filter. Select this and you should have, among other things, a choice of Reset to Defaults. Click this so you have known start point (This is based on Win7, I don't know how 8 or 10 works for program groups). Then:

1. In NPVR Settings>Decoders>Audio Decoders>AC3 Audio, select AC3Filter
   
2. Click the box with 3 dots to the right
   
3. On the Main tab of the AC3Filter configuration screen, for Output format, confirm or choose 2/0-stereo
   
4. Click OK
   
5. Exit settings and see if it works.
   

[helpful55]

Try this to get AC3Filter working:

This assumes you are using the stereo analog audio output of the NPVR computer. If this isn't the case, you'll have to better explain your setup.

In your Windows start menu, you should have a program group for AC3 Filter. Select this and you should have, among other things, a choice of Reset to Defaults. Click this so you have known start point (This is based on Win7, I don't know how 8 or 10 works for program groups). Then:

1. In NPVR Settings>Decoders>Audio Decoders>AC3 Audio, select AC3Filter
   
2. Click the box with 3 dots to the right
   
3. On the Main tab of the AC3Filter configuration screen, for Output format, confirm or choose 2/0-stereo
   
4. Click OK
   
5. Exit settings and see if it works.
   

This seems to be working fine now, it still defaults to the first of the Audio stream selections and that brings in full audio. Selecting the second selection which is sometimes spa usually kills most or all audio. I am not sure what has gotten this to work now, I don’t think I did anything in the settings that did this, maybe it was the reset like you suggested. Also maybe because I had completely exited NPVR and restarted recently to test it before I responded to you, maybe changes took effect. I even tried a couple small test recordings and they play back with proper audio. I’ll respond to your ideas here:

I’m not sure what you mean by using the stereo analog audio output of the NPVR computer. If you mean how I am feeding my external sound system. I just have a standard 3.5mm stereo plug (green) running to my 2.1 system. It has a separate sub but not separate sub input, just a single stereo L/R plug. It still gets plenty of sub output without any separate sub channel. No other settings or alternate setup. Like I may have mentioned my whole system has always and still works fine for all audio and video/audio streams and players other than NRVR and WMC for some reason. Everything is handled internally until the 3.5mm plug outlet.

Yes I had that reset in the start menu with my W7 and I went through that reset.

I actually have no output format selection for 2/0 stereo. There is a whole list and the one it is on which I left it on for now is just “stereo” and is working that way. I suppose stereo is certainly what you would call standard 2.0. A few other similar selections are 2.1 stereo, and one for 2/1. What would be the difference between 2.1 and 2/1? ( / )? Would the 2.1 stereo be the best or just stay where I’m at since it seems to work fine?

So I’ll try this for a while and report back if any more problems, otherwise we’ve got it. I really like the great picture and recording quality with NPVR and the way it will work in the background so my pc isn’t tied up otherwise. I can also play the file in WMP so I have those viewing controls. Now on to trying to see why WMC has this same kind of problem (still, I tried it also). I don’t know where its decoder setting are at. I like to have more than one option in case one has problems. Thanks lots.