As of late, I've been trying to get better audio to come out of my laptop, after discovering that my Creative SoundBlaster Live! 24-bit External [http://www.soundblaster.com/products/product.asp?category=1&am...duct=10702] (it's a USB sound card with analog 5.1 outputs, and a full optical SPDIF-out) is nigh useless in Windows Vista for everything but music listening. Now, my laptop is an Alienware Area-51 m5790 [http://www.notebookreview.com/default.asp?newsID=3586&revi...ware+m5790] -- it was advertised to have 7.1 surround sound audio, and sure enough it possesses a Realtek ALC880 HD Audio chip. Now, I completely lack the analog 5.1 connectors (most laptops do), but I do have a blue 3.5mm analog Line-In jack, a green 3.5mm analog Headphone jack, and a red 3.5 mm analog Microphone input jack. And, according to my Realtek HD Audio Control Panel, I have a digital SPDIF output -- seemingly integrated into the green 3.5mm analog jack somehow.
Many soundcards integrate SPDIF output into the analog 3.5mm jack, as in the case with the SB X-Fi. What you need is a digital coax SPDIF cable, and a 3.5mm-Mono RCA adapter, remember it has to be mono and not stereo, you can get it from RadioShack. You will then connect the adapter to one end of the SPDIF cable, and plug the adapter into the 3.5mm output jack, and the other end of the cable into your digital speakers or receiver.
I'm using this setup with my SB Audigy 2 ZS and Logitech Z-5500 speakers, the Audigy 2 has a 3.5mm digital out jack but it's not integrated into the analog output jack. Hope this helps.
ADK 1Q AR Laptop
Core i5 520M | 4GB RAM | ATI HD4570
Yes, but as DP said, if you cram enough channels into it (like 7.1), the low amount of shielding on the cable could be a problem. I personally used generic RCA cables just like that for years for 5.1 and never had a problem, though.
I would buy a cheap RCA cable and see if it works well enough -- if it doesn't, you're only out 1 or 2 clams.
You MIGHT need a 5.1 sound card, but you may have the same situation I had with my laptop. I only had three 3.5mm analog audio outputs -- but one of those audio outputs (the green speaker output) was dual-mode. It could function as a standard, two-channel analog audio output (for regular headphones and speakers), or it could function as a 5.1/7.1 digital S/PDIF audio output.
Unfortunately, as you noted, your Logitech speaker set does NOT have a S/PDIF audio input... so you would need some device capable of converting the digital surround sound output from your laptop to analog surround sound that you could then plug into your speakers.
It is with a heavy heart that I must tell you that such a device is unbelievably rare. I've searched long and hard for one, and actually ended up owning one entirely by accident -- the "amplifier" and/or control box for the Tritton AX360 5.1 surround sound gaming headphones just so happens to have this capability -- but they're reallys**tty headphones, so don't buy them just for that box (besides, the box only accepts OPTICAL S/PDIF, not electrical over RCA).
Your best bet would be to probably purchase this sound card:
...(besides, the box only accepts OPTICAL S/PDIF, not electrical over RCA)....
Even though old thread, some folks might not know that SPDIF converters
Optical==>RCA(coaxial) or RCA(coaxial)==>Optical
are available as well. I don't remember the brand I bought but I got them for about $15 each and all have been working great for years. (brand is not printed on the ~1.5"x2.5"x0.5" box)