[taxipaul]

I have a standard Tv, sky+hd and a DVD player with 5.1surround sound. When I play a DVD all the speakers on the surround sound work fine , when I come to watch a tv programme and listen to the sound through my speakers that are connected to my DVD set up ibonly get sound through 2 of them, those being front right and the sub woofer. It has got me totally baffled . The DVD Abdul sky box are connected by an optical cable, and the system has in the past worked fine. Any ideas?? Thank you in advance.

[Chasing Shadows]

You will only get surround sound from the Sky box when listening to a channel (and programme) which is broadcast in surround sound. The majority aren't.

Which channel in particular were you listening to? Try Sky Movies - most of them are encoded with a Dolby Digital 5.1 soundtrack.

If you press the Info button on the Sky remote while tuned to a Sky channel you will see whether the audio is stereo or surround. If the infobar contains DD, it is broadcast in DD5.1. If not, it is broadcast in stereo (so only the two front speakers and the sub-woofer will play any audio).

[taxipaul]

Thanks for that very quick reply.
I have/had tried sky movies and those with DD and still only one front and the sub woofer work.

still mystified.

[chrisjr]

Quote:

Originally Posted by taxipaul

I have a standard Tv, sky+hd and a DVD player with 5.1surround sound. When I play a DVD all the speakers on the surround sound work fine , when I come to watch a tv programme and listen to the sound through my speakers that are connected to my DVD set up ibonly get sound through 2 of them, those being front right and the sub woofer. It has got me totally baffled . The DVD Abdul sky box are connected by an optical cable, and the system has in the past worked fine. Any ideas?? Thank you in advance.

Have you checked to make sure the left front speaker is actually working? Try swapping the left and right speakers around on the connectors on the back of the unit. That should indicate if the amp is putting out any noise on the left front channel and whether the "left" speaker is working or not.

I can't see why you would get stereo sound via only the right and sub speakers. Unless there is something serious screwed in the amp or you've got the Left Front and Sub swapped round on the back of the amp! So it could be the left speaker or the left output of the amp is not working.

Sometimes if you are listening to a full 5.1 surround audio track you can miss the left or right speaker working as generally the centre speaker carries most of the dialogue and other sounds so masks the 'missing" speaker to some degree.

[chrisjr]

Quote:

Originally Posted by taxipaul

Thanks for that very quick reply.
I have/had tried sky movies and those with DD and still only one front and the sub woofer work.

still mystified.

Have you set the Sky box up to output DD over Optical? If it's set to PCM (or LPCM) then it will output stereo regardless of the broadcast audio format.

[Chasing Shadows]

Have you selected optical input as source on the home cinema? It's possible that you have the TV's audio output selected as source, and this is likely to be stereo only.

[taxipaul]

Quote:

Originally Posted by chrisjr

Have you checked to make sure the left front speaker is actually working? Try swapping the left and right speakers around on the connectors on the back of the unit. That should indicate if the amp is putting out any noise on the left front channel and whether the "left" speaker is working or not.

I can't see why you would get stereo sound via only the right and sub speakers. Unless there is something serious screwed in the amp or you've got the Left Front and Sub swapped round on the back of the amp! So it could be the left speaker or the left output of the amp is not working.

Sometimes if you are listening to a full 5.1 surround audio track you can miss the left or right speaker working as generally the centre speaker carries most of the dialogue and other sounds so masks the 'missing" speaker to some degree.

ALL speakers work when playing a DVD/Blueray.
All speakers work when i do i surround test.
Only 2 speakers work when i have normal tv on.
i have changed my optical cable, and tried av plugs(red/white coloured ones)
I really dont want to buy a new one as this is clearly "working"

[56up]

What make is the surround sound system?

Mine you can set to Pure Audio on any input and when that input is selected I will only get stereo sound with no sound processing. You can change the sound processing individually for each input. Does your system have that facility?

Also, most surround sound systems have DSP (digital sound processor) that can give pseudo surround or extract the prologic information from the stereo signal. Can yours do that and, if so, what setting are you using?

[spiney2]

all tv is broadcast in surround sound format. whatever the actual source is.

when the 5.1 signal is not broadcast, a home cinema system will have to use the pro-logic decoder to correctly interpret the dolby surround information in the 2.0 sound feed. so its a question of setting up correctly or possibly a fault ........

[spiney2]

Quote:

Originally Posted by 56up

What make is the surround sound system?

Also, most surround sound systems have DSP (digital sound processor) that can give pseudo surround or extract the prologic information from the stereo signal. Can yours do that and, if so, what setting are you using?

the broadcast signal is dolby surround. ie, pure sq matrix.

pro logic is the particular type of decoder used in most home cinema systems. it partly compensates for the haas effect - used in cinemas - not working in small living rooms ........

sorry to be pedantic. and i dont know the correct setup for the particular home cinema system being discussed .....

[spiney2]

..... no heavy machine gun fire, good (removes flak jacket) ........

..... i wd suggest removing the optical cable - in case the digital carrier signal with nothing on it is being "auto detected" then make sure the analogue 2.0 inputs are working, then fiddle around with settings so that pro logic kicks in ...... then u can try the optical again ......

... if set up correctly, in theory, it should default to 2.0 via pro logic when there is "no content" on the 5.1 ........

[chrisjr]

Quote:

Originally Posted by taxipaul

ALL speakers work when playing a DVD/Blueray.
All speakers work when i do i surround test.
Only 2 speakers work when i have normal tv on.
i have changed my optical cable, and tried av plugs(red/white coloured ones)
I really dont want to buy a new one as this is clearly "working"

It is perfectly possible that when fed with a plain stereo source that only two speakers will produce any sound. They should be the left and right front pair, with possibly the sub as well. So in that respect nothing is wrong.

But what you seem to be getting is only right front and sub? If so then that is very definitely wrong. So either the left front and sub speakers are connected incorrectly (swapped round) or the system is faulty.

You need to check carefully whether or not the front left speaker is really working. When you do a surround test do you have the ability to select each channel in turn? And is there a display that indicates which speaker should be making a noise? If so does the display match the speaker?

So double check all the speaker connections and ensure the correct speaker is connected to each amplifier output.

Swap speakers round to see if the fault follows the speaker or stays on the same channel. For example if you swap the left and right speakers physically and the right channel is now dead that implies it is a speaker fault. If however the left speaker is still silent that implies an amplifier fault.

It's basically a process of elimination. Checking everything in a logical sequence to ensure that each connection is correct and that each speaker works properly.

[spiney2]

surround sound systems usually have some adjustment for the sub, but if what comes out of it sounds "fairly normal" at human speech frequencies (ie 3 KHz) then this does suggest it is on the wrong output socket. which u can check by tweaking the crossover frequency adjustment and listening for any difference .......