OTA HD Sound Issues

[chughes]

I just set up my HD antennae on the weekend and got it working with Sage. I am using an Hauppauge HVR-950 tuner for the antennae. I have got Sage to scan for channels and it picked up about 24 or so (I'm downtown Toronto), only a dozen of which I will keep in my channel setup.
However, of the keepers, several channels seem to have an issue with the sound. On some, I can here quiet background noise/music but voices are very muffled. Cranking the volume up produces a hideous quality that reminds me of early Real Audio broadcasts. Some channels are fine, just kind of quiet, so I can turn it up if I have to.
Has anyone experienced this before? I'm not sure if the problem lies with the HVR-950, Sage, my receiver, or a combination.

[chughes]

I should also note that until I hooked up the antennae, I got all my programming through Rogers, but their analog signal - straight from the wall. I have the STB, but never bothered to hook it up because I would need 2 of them and have to wrangle with separate IR blasters. Anyway, sound on the analog channels is fine.

[SWKerr]

It is your Audio decoder. Try FFDshow. If I recall it is only the 5.1 shows that sound messed up.

[wayner]

I have seen this before with OTA channels with DD5.1 but mainly on some of my TVs without receivers. I thought it was an issue where Sage was sending the left and right surrounds to my TV via analog stereo connection rather than a combination of all channels. I remember watching golf from Channel 4 in Buffalo and you could barely hear the announcers but the birds were quite loud.

[chughes]

Thanks to both of you. I'm going to try messing with the decoders per the suggestion and see if that helps. All the audio is output from my mobo via digital to my receiver. I'm not using my TV speakers at all. I think my receiver is reporting PCM and attempting to reduce the stream to stereo - 2 channel. Anyway, I think the decoder is worth a look.