Very low volume on QAM channels

[feniks]

mian, I have very similar experience. since there is no way to really compare it I can only say that we probably observe same thing. i summarized my experience as well based on your post (almost identical), trying not to copy you too much

in short I see you are not using Set-Top-Box and have Basic cable TV (just as me, right?). it should make things easier to compare exp.

Here it goes:
For me basic channel (analog) lineup volume for me differs from channel to channel (one is loud while other stays almost silent). that's normal i guess, e.g. FoodTV or CNN is always loud while let's say FX or SpikeTV or SCI-FI is quieter.

In my case QAM channels are still much lower in volume than all analog channels. it's sort of annoying, but fixable with general volume knob on my speakers and master volume setting in Windows.

the problem is that in order to have QAM audio volume on level that allows me to understand what people on TV are saying I need to turn it up to the point where other analog channels are almost screaming. I'm not saying it's a real problem, just an annoyance, nothing more.

since i'm not alone (and you are Hauppauge user as well) as you said there are probably 2 options (still need to verify 3rd one):
a) audio signal volume varies greatly between channels, especially in no STB setup between FREE QAM and most/all analog channels - this probably was manipulated by cable company in order to make people get STB that fixes such issue
b) Hauppauge drivers for digital tuner have problem with audio volume
c) there is another problem

I still need to check out if WinTV PVR gives me same/better/worse audio loudness on QAM channels than GB-PVR setup. I'm not saying GB-PVR is guilty, I just say that the components that GBPVR in my setup uses (complex mix of decoders, renderers, mux, drivers, etc) may differ from the one used by another similar applciation e.g. WinTV.

[feniks]

hmmm, LOL
discovered something odd that may be the root cause.

Namely, when audio decoders (both audio and ac3) are set to ffdshow all works OK, just ac3 channels are lower in decibels.
However when i left only AC3 as ffdshow and switched audio decoder to InterVideo Non-CSS Audio Decoder for Hauppauge then i got no audio at all on digital channels... what a puzzle...

[wutangmo15]

I also have Comcast and experienced low volume using QAM. I've resolved the issue by increasing the master volume to 300% in ffdshow audio configuration. Now the sound is around the same level as my analog recordings.

[Snooze]

I had this recently on my HTPC, trying to fix playback of MP4 files (perhaps too much tweaking). I use K-Lite Codec pack (shunned by some) but it has treated me well. I used the K-Lite codec tweak in the "packaged software" and "check for broken codecs" was in there. Sure enough it reported some. Also there was a ... cant remember what it was called, but it translated to something like "maximize volume" or something to that degree. After I ran that, all was good. My 2 cents.

[whurlston]

That setting would be "Normalize volume". 5.1 audio is usually broadcast much lower than 2.0.

This is one reason why you have to turn down the volume when the commercials come on (the sound switches form 5.1 to 2.0). The other reason is that the commercials crank the gain to get your attention.

In the HTPC world, decoder settings can make it seem the exact opposite though.