Topic: Surround sound

[Clive]

Today I have replaced the 42" plasma TV I agonised over in THIS OLD THREAD.  After nearly five years the picture is still very good but a fault developed with the sound which has become steadily worse over time.  These early plasma sets stored their electronics in a "media centre" which was a separate box with inputs and outputs for just about everythung imaginable.  My 2002 prophecy of 42" sets selling for £1000 within 5 years was very accurate!  But I've actually gone for a Sharp 42" LCD this time.  I'm not really convinced that the picture is as good as the plasma but I'm stuck with it now! 

The problem I have is connecting my surround sound system to it.  I  have a Yamaha amplifier with a output sockets for 6 speakers which was connected up to the media centre which also had sockets for 6 speakers.  The new TV doesn't seem to have all those facilities so what am I supposed to do to get my home cinema working again?   

[Simon]

You can only connect the TV to the amp via the 2 channel stereo phono (red and white) inputs, Clive, but if you want cinema sound, you will have to connect the DVD player to the amp (assuming it's a surround amp), via either an optical or digital coax cable.  Same goes for any other boxes you have.  You will have to connect each device separately to the amp, and then switch the function on the amp to whatever device you want to hear.

[Clive]

That's a relief!  I certainly have optical cables but I will have to check up on digital coax cable.  Thanks very much Simon!

[Sandra]

You dont need to spend a fortune on digital coax cable Clive.
If you have some stereo phono to phono cable you can just use one of the pair of wires as theyre the same thing 

[Clive]

I still don't understand how 6 speakers can obtain information individually from just one pair of wires Sandra.  With my old system each speaker had its own dedicated cable from amplifier to DVD. 

[Sandra]

Its not even a pair of wires in the case of a digital signal sent via coax or optical Clive.

Its just a stream of digital data, the same as in your ADSL phone line, that is decoded by the amplifiers internal decoder to send the sound to the correct speaker at the correct time, with the correct volume 

[Clive]

Thanks for the explanation Sandra.  I know I have an optical cable so I'll try that out first.  Now that the media centre has gone I can transfer the amplifier/decoder into the same cabinet as the skybox and dvd recorder thus tidying up a few miles of cable.  That should please Mrs Clive! 

[Simon]

I've never heard of an analogue phono lead being split to form a digital coax, Sandra.  I would doubt that the same sound quality could be achieved by that method.  :Dunno:

[Sandra]

I use a few of them Simon as I have 3 devices with coax digital out running to a 3 way stereo speaker selector switch.
I just use one input to each switch and one output to my amp, the red ones in my case.

As its a digital signal then quality doesnt really matter, it just detects "on" or "off"  or 1 or 0 if you prefer and either works or it doesnt, you never get a degraded signal with digital.

A coax digital cable has an earth wire and a feed wire, just the same as a phono to phono audio cable which normally come in pairs or triple, if composite video is used, as its digital and not analogue then it doesnt even need to be screened.

A lot of shops will try and sell you expensive cables for lots of things but where you may need a good quality cable for a long run in analogue you definately dont need anything special for digital 

[Clive]

I had to remove the feet from the amplifier to reduce the overall height but all my units are now in the one cabinet and there is not a single cable to be seen!  Don't look behind the TV set though!     I had a minor disaster when I removed the amplifier from the old cabinet because the optical cable plug snapped off.  I've put it back together and taped it with pvc tape and I don't see why it shouldn't work.  The only thing left to do now is switch it all on and insert a DVD to see if it actually works!   

[Rik]

I just wonder if you're going to have a heat problem due to lack of ventilation, Clive?

[Clive]

That thought had occurred to me too Rik.  Without the feet the base ventilation holes are covered up and the DVD recorder is blocking the top ventilation holes.  With the old set up, the amp had to be switched on all the time in order to hear the TV sound.  Now it will only have to be switched on when I'm playing a DVD so it's not going to be worked too hard!   
. 

[Simon]

Clive, you may well find that DVDs get extremely hot when played in a machine placed on top of an amp.  Mine did, and in the end, I had to swap things about.  It's surprising how much heat these AV amps generate, and they really should be ventilated, at least at the top.

[Clive]

I have to get a new optical cable anyway Simon because the old one doesn't work.  I'll take that opportunity to shuffle things around.

[Rik]

Might be worth fitting a fan in the case too, Clive.