I was looking into "cheap" surround sound systems and was amazed at the disparity of choices and overall stagnation of the scene. There are a few $50-$70 systems, but they include use a DVD player as "receiver" and have no other form of input. These were altogether useless for me because I was looking for something to connect to my Xbox 360.
I was walking past my poor dead desktop for the millionth time and started thinking about my desktop speakers. I have a decent digital quadrophonic (4.1) set of speakers from Boston Acoustics that have followed me for years as my primary set of desktop speakers. I haven't made use of them with my laptops because they refuse analog signals and only respond to digital signals. I started wondering if I could use them with my Xbox 360...
My first stop was Radio Shack, because I forgot for a few minutes that we live in the era when Radio Shack was just another uninformed consumer grinder. Then I turned to the internet. The Xbox 360 has an optical surround output, which is named Toslink (after Toshiba). The speakers have a coax surround input, which is named SPDIF (after Sony and Phillips). Come to find out, thanks to Wikipedia, that the signals are the exact same for both Toslink and SPDIF with the only difference being between cabling types, one of which uses extremely expensive, short-distance-only cabling (Toslink) and the other using the same forms of cabling man has used for decades in audio (SPDIF). It was then just a simple matter to get an optical to coax converter from Amazon and voila I have surround sound now on my 360 for just $20 and a 6 or 7 year old speaker set.
Okay, for my technical friends, I lied a little, it's not really the "exact" same signal some Toslink or SPDIF devices may send/respond to slightly different signals, but the protocol (meta) signal is the exact same for both. You just have to keep in mind that there are two perpetually competing encoding formats for the actual data over that protocol: Dolby Digital (AC-3) and DTS. My speakers only respond to/decode Dolby Digital, but that's fine because the Xbox 360 does hardware transcoding between the two as necessary and its a simple setting to fix the output in one or the other. Therefore I don't have to worry about it. If a game or DVD only has DTS output I can still play it because the Xbox 360 does that work for me, no need for a more expensive receiver than the simple AC-3 one already built into my speakers.
Interestingly enough, the ability to transcode between AC-3 and DTS is a requirement in the HD-DVD specification and all HD-DVD players should be able to do it (that way film producers can encode in just the format they deem best, saving them a few bucks, and consumers can play it regardless of their own setup).
Here's where I start to wonder about the state of current surround sound electronics: what do I need such expensive receivers for? Why do I still need to pay for Dolby Pro Logic? I don't watch any VHS tapes any more and think "Man I wish this was in psuedo-surround sound". Why do I need to pay for both Dolby Digital and DTS reception when modern systems can do their own transcoding? Beyond that, why does a simple switch between several sources and a single speaker set, with simple digital to analog conversion and a little old amplitude modulation knowledge, need to cost $150+ dollars?
So, digital SPDIF computer speaker set and a simple converter and that's all I needed for all the surround I could want from my Xbox 360, but no one in the retail world had a single clue. I visited Radio Shack, Circuit City, Wal-Mart and Best Buy and no one out there seems to understand that the Toslink and SPDIF worlds are the exact same and that converters exist. Further reason for me to give up on shopping at retail stores altogether... I still don't understand why there aren't more simple digital-only solutions out there. Speakers have been sold for computers that just do Dolby Digital decoding for about a decade now, but no one in the "Home Theater" world could sell me just a Dolby Digital decoding set that I could hook directly into my 360. I don't understand why there isn't a growing market for digital-only surround sound in the "Home Theater" segment.