Hi I've recently purchased a Hisense 49" TV which has a optical out connection for the audio and a Logitech Z506 speaker system which is can support 5.1 surround sound.

In order to connect the speaker which is analogue to the TV which has digital audio output I have purchased this: https://www.amazon.co.uk/gp/product/B00AZHNXNO (ESYNiC Digital to Analog 5.1 Audio Gear Adapter Sound Decoder SPDIF RCA Dolby AC3/ DTS Optical Coaxial Input - Support for HDTV DVD Player Blue ReyDVD DVD SP3 Xbox 360) and https://www.amazon.co.uk/gp/product/B0009N1MV4 (Wired--up 3.5mm Stereo Jack/RCA Plug X2 Y Cable - Black)

Will this work? Currently I get sound out of all of the speakers but it feels the same as as 2.1 system. I am still waiting for the 2 splitters to arrive.

I'm not really clued up on surround sound. Got the speaker system for cheap on ebay so just wondering if the above setup is possible to do.

pics of the ports on the speakers and tv: http://imgur.com/a/XWHK4

Pretty sure you only need an optical to rca (stereo) converter and a set of stereo phono leads. Alternatively use headphone to stereo phono. Use 3.5mm adapters where necessary.

The audio connections at the top (green, black and yellow) are for a sound card.

The 4x3.5mm connections on the sub are for the L, C, SR, SL speakers, right speaker connects via multi pin connector.

Don't think you'll get true 5.1 from your connections, just surround sound 3D from two channel as advertised.

Provided you match up the audio outputs of the digital decoder to the inputs on the speaker it should work OK.

If you use the stereo phono sockets on the speakers then you will just get stereo out of them. Probably the same signal fed to the rears as the fronts and a mono mix sent to the centre.

But once you have the three phono to jack adapters set up to connect the six outputs of the decoder to the input jacks on the speakers you should be good to go. You do have three phono to jack adapters don't you? You can only use the jack sockets on the speakers for surround, you can't connect to the two phono sockets at the same time.

It is likely one of the jacks will be left & Right Front, the second Left & Right Rear and the third Centre and Sub. So you just need to make sure you pair up the output phonos on the decoder to match.

Yes atm the sound is coming out of all the speakers but it "feels" like 2.1. I am awaiting delivery of the jack to phono adapters.

I have only purchased two adapters. So from what you are saying I cannot use the two phono connections (red/white r/l) at the same time as the other 3 phono connections (green, orange and black) if so I guess I'll modify my amazon order and add another adapter on it.

The green, orange and black are jacks not phonos.

I found the manual for the speakers (if it can be called that!) on their website. Might as well have not bothered with the English translation as it told me three eighths of sweet FA that was any use. It is entirely possible that the two phono sockets (red & white) are wired via the green jack socket (left & right front) so you can use either the jack or the phono sockets with the jack switching away the phono sockets if you plug a lead into it.

But it doesn't explicitly say this in the manual.

You could test the theory though. If you have something connected to the read & white phonos try plugging a jack lead into the green socket (doesn't need to be connected to anything). If that kills all sound then that suggests the red & white phonos are wired via the green jack socket.

Then try the orange and black sockets to see if they mute the rear pair and centre & sub (depending on which socket you plug into).

If they do then you could get away with using the red & white phonos for the front left & right and the orange and black jacks for the rears, centre and sub.

ahh okay I kind of understand. I will await delivery of the adapters and update on how it went.

Surely the audio outputs from the converter need to be connected to the audio inputs on the sub? That would require matching up the colour code from a soundcard to the audio channels correctly, ie Black = Sub and Center.

Pretty sure I tried this a few years ago for a friend, tried everything but only got audio from the stereo audio inputs. Maybe things have change with more current models.

More importantly, does the TV support 5.1 passthrough, not only from its tuner but from external sources too?

Isn't that what I said?

Though not sure what the relevance of a sound card is?

The Speaker system the OP has uses three jack to jack leads to connect a 5.1 audio source to the speaker. That is why he has bough the phono to jack socket adapters, though it might have been better to have used jack to phono plug leads and ignore the leads provided with the speaker, but too late now.

It is just a matter of plugging the phono plugs on the adapters into the correct sockets on the decoder box so you get the various signals appearing on the correct speakers. Though from what little there is in the manual the three jack plugs don't appear to be labelled as to what speakers they feed. So some trial and error may be required to match up the decoder outputs to the speaker inputs.


What were you trying to connect to what?


That is a good point. However the decoder the OP has does sport two optical inputs and one coaxial input. So even if the telly can't pass surround from, say, a DVD player provided the player has a digital audio out the OP can plug it direct to the decoder and just switch inputs as necessary.

Looked to me that you were saying connect the 6 audio outputs to the speakers.

"Provided you match up the audio outputs of the digital decoder to the inputs on the speaker it should work OK."

The audio inputs at the top of the sub ( green, orange and black ) are used for a soundcard/pc connection, find the colour code for the soundcard and if will give to the correct matching for the inputs.

Colour code:

Green = Front Speakers
Orange = Sub and Center
Black = Rear Surrounds

All OP has to do is pair up the speakers as above to jack adapters and then connect to corresponding colours on the sub. Then fingers crossed.


TV with optical to DAC with 5.1 analogue output to similar PC speakers as OP with PC soundcard/stereo audio outputs support. We tried what is being discussed here but had no joy, only connection that gave us audio was the twin phones.

Definitely a solution if 5.1 passthrough is not possible, providing true 5.1 can be achieved by proposed connections.

Not sure I see the confusion the inputs to the Logitech system are on a speaker are they not? See what you mean about the soundcard now.


There is no fundamental difference between the outputs on a PC soundcard and those on the DAC. The only real difference is the connector format. So with appropriate leads there should be no problem at all in connecting the DAC to the three jacks.

And as I posted above it is entirely possible that the two phono sockets on the speaker are wired via the switched contacts on the green jack socket. There doesn't seem to be any way of selecting which set of inputs are in use as far as the next to useless manual shows anyway.

http://www.logitech.com/assets/33015...05326gsamr.pdf

The only controls on the entire system appear to be power on/off, volume and a level control for the sub. No input selector that I could see. So either it switches away the phono sockets via one of the jacks or it is really nasty and just connects the phonos and jacks together with no switching. Hence why I suggested the OP see what effect plugging a jack lead in had on the sound when connected via the phonos.

Probably just the way I read it.

Added colour code for ease of connecting.


If the OP can get it working all well and good, but primarily it is a pc speaker system, which in the past I've found they only work to their full potential if you have the right dedicated inputs and outputs.

I can't see that there is any significant difference between the audio signal coming out of a PC and the digital converter the OP has. The connector format should make not a blind bit of difference to that.

There could be a difference in voltage level but shouldn't be anything the speaker can't cope with.