Why does my z-5500 setup do this?

[Steve]

I have a Comcast digital TV package, and a z-5500 setup connected to my Motorola cable box via optical.

Most of the HD/digital channels have nothing coming out of the rear speakers. I'm at the point where I'd rather watch the SD/analog channels in StereoX2 just to have sound coming from a source closer to my ears.

On some HD channels it helps to turn the surround all the way up, but this is not always the case.

Any ideas?

 

[BassBomb]

Do you know how the cable box is bitstreaming (if it is at all?)
What mode is your z5500 set to decode?

 

[Steve]

Not sure if the cable box is bitstreaming, how do I find that out? The z-5500s go to Dolby Digital on the HD channels, and I can't change that to anything else. On the SD channels they go to StereoX2.

 

[Steve]

Cable box is a Motorola 6200-2005.

 

[alcoholbob]

Well if it "sometimes works" then the source is the culprit, not your speakers.

 

[krotchy]

Keep in mind, a lot of TV channels only encode in Stereo to begin with. The ones that do send surround signals still need a surround source. Generally I find live sporting events have sound, and some primetime TV shows as well, but you aren't going to get surround from Food Network, The news and most other content on TV.

 

[Slick5150]

You shouldn't have sound coming out of your rears a lot of the time. The dialogue should be coming out of the front. When you're watching something in SD the Z-5500's are basically just taking a stereo signal and forcing sound to the rear channels, which is why you hear it more often then.

Tune into a sporting event in HD, you should hear crowd noise and whatnot coming out of the rears.

 

[Steve]

I do watch sports in HD, it's just annoying to have to turn up the rears to balance the sound from all speakers. Especially if I flip to another channel.

What's even more annoying is when I flip to another channel, the rears turn off altogether. I have to either change the source briefly (e.g. hit COAX on the remote, then back to optical), or turn them off then on again.

 

[krotchy]

Originally posted by: Steve
I do watch sports in HD, it's just annoying to have to turn up the rears to balance the sound from all speakers. Especially if I flip to another channel.

What's even more annoying is when I flip to another channel, the rears turn off altogether. I have to either change the source briefly (e.g. hit COAX on the remote, then back to optical), or turn them off then on again.

Sorry, can you clarify this? It sounds like you are just saying if you turn to a 2.0 source, the speakers go 2.0 until you go back to a 5.1 source or reset the signal, Or does this mean you turn to say a 2.0 station and the rears turn off, then you turn back to the 5.1 station and the audio still doesn't come out of the rears? If that is the case you might need to contact logitech support.

 

[FP]

Sounds like you have 2 issues...

1. You expect surround output from stereo (DD2.0) sources.
2. You need to calibrate your speakers.

I have the z-5500s hooked up to my computer and have them calibrated and I never have to change the individual levels of the speakers.

In my HT my receiver typically shows a DD2.0 signal coming into it from my cable box. I have it matrixed out to 5.1 but I would say 75% of the shows I watch are all 2.0.

I am guessing the Z-5500s can't matrix DD2.0 sources to 5.1.

 

[Steve]

Originally posted by: krotchy

Originally posted by: Steve
I do watch sports in HD, it's just annoying to have to turn up the rears to balance the sound from all speakers. Especially if I flip to another channel.

What's even more annoying is when I flip to another channel, the rears turn off altogether. I have to either change the source briefly (e.g. hit COAX on the remote, then back to optical), or turn them off then on again.

Sorry, can you clarify this? It sounds like you are just saying if you turn to a 2.0 source, the speakers go 2.0 until you go back to a 5.1 source or reset the signal, Or does this mean you turn to say a 2.0 station and the rears turn off, then you turn back to the 5.1 station and the audio still doesn't come out of the rears? If that is the case you might need to contact logitech support.

If I'm on a TV station where the control pod says DD Digital for the audio (a digital/HD station), and I switch to a station broadcasting in stereo (an SD station), I get stereo sound front and back as I have set it (my default is StereoX2) . However, when I switch back to an HD station, the rears go silent. I have to either power the pod off and on, or briefly switch to coax and back to optical to get those rears going again.

I could even be watching an HD station and if the signal hiccups, the rears go out too. Same happens on an SD station broadcasting in stereo, though less often.

Originally posted by: binister
Sounds like you have 2 issues...

1. You expect surround output from stereo (DD2.0) sources.
2. You need to calibrate your speakers.

I have the z-5500s hooked up to my computer and have them calibrated and I never have to change the individual levels of the speakers.

In my HT my receiver typically shows a DD2.0 signal coming into it from my cable box. I have it matrixed out to 5.1 but I would say 75% of the shows I watch are all 2.0.

I am guessing the Z-5500s can't matrix DD2.0 sources to 5.1.

1. No, hopefully I have clarified this above.

Tell me more of this calibration? I have my z-5500s plugged into my cable box via optical, and my HTPC via coax.

 

[FP]

That is a very odd problem. It sounds like your cable box is wonky, I can't imagine a signal being decoded but cutting off certain channels.

Re: the calibration... I used an SPL meter set up in my seating position to calibrate each speaker to a certain sound level. This would likely fix your low rear speaker issues but won't fix your missing rear speaker issues.