Thanks htfan17 for listing the alternatives. It will be helpfull. Will the Logitech speakers give the true 5.1 digital surround sound? I want to explore more on option 2 & 3. Option 1 seems to be bit expensive.
But what I am not getting is then why are there 5.1 speakers which does not give the kind of surround sound effect for which people the buy them? Are they worthless?
You are Welcome moday. Btw, clicking on thank button is sufficient . No need to mention it.
To answer your first question, yes Logitech's one and only model Z906 has a coaxial as well as optical input which will connect to your STB and give you true 5.1 surround output.
To answer your second question, the cheaper and local 5.1 speakers in the market are all capable of providing true 5.1 But they are not made for cable box/ STB usage. Their primary usage is limited to PC /Laptop 5.1 sound card and / or the 5.1 analog plugs found at the back of every standalone dvd player today. When connected to either of these, any 5.1 speaker no matter how cheap will give u the true surround sound. The only thing that will differ is the quality of sound itself because of the speaker brand/ build quality.
The Logitech Z906 and Yamaha HT system are on borderline pricing between 19-21K. So u may choose either one as per your need. I wud say go for Yamaha as its more flexible and also has HDMI inputs to take from STB. IN logitech, u will be limited to use the provided speakers and the cable lengths are limited. But in systems like Yamaha/Onkyo/Denon/Pioneer, in future, u can buy and use high end speakers of different brands and use as long independent cable as u want. Though logitech is the most powerful and recomended 5.1 speaker set of its category (compared against iball, Intex, F&D, moserbaer, Creative etc), all that flexibility of Yamaha isn't possible with it.
To answer your further question, I searched a bit on official websites for latest models and here is list of DVD/BD HTIBs having Optical Inputs at the back. Sorry I cudnt go through alll. The website prices are all MRPs so most probably they are all cheaper in showrooms. So please call the showrooms and check for latest prices. The only feature u r looking for is whether it has got Optical input.
a few models on quick search:
Sony DAV-DZ350
Sony BDV-E3100
Philips HTD3510G/94