I had to temporarily disassemble my primary multimedia PC system last week (it sits in front of a window that was being replaced) and decided it was finally time to provide some thoughts on multimedia surround sound systems. This is long overdue. How long overdue? One of the systems I intended to review, Klipsch's ProMedia 5.1, was discontinued a few years ago and replaced with the ProMedia Ultra 5.1. The other, a Logitech Z-5500 system the company was kind enough to send over last year, is no longer a new model either. Logitech added the Z-5450 to the line, which offers wireless surround speakers, though, unlike ProMedia, at least the Z-5500 is at least still on the market!
Both THX systems are impressive, and can pressurize my small room to over 110 decibels without distortion - true THX reference level, and way too loud for normal listening without causing permanent hearing damage. As a PC peripheral, they're definitely pricey add-ons. Hard core gamers buying $4,000 PCs should be able to set aside a tenth of that for audio, but with a $400 budget PC it may be harder to justify spending nearly the same amount on the speakers as on the whole computer. Still, when considered as home theater speakers, the systems are quite reasonably priced - you simply won't find HTIB speakers under $400 that compete with them.
However, there is a huge caveat: multimedia systems are designed for use with a PC. With XP Media Center systems and large LCD monitor/TVs proliferating, perhaps that's not as unusual a proposition as it was a few years ago, but there are other considerations as well. Multimedia systems are designed for near-field listening: like studio monitors, speaker designers know where you'll be sitting -- right up in front of the speakers, not ten feet away on your couch. Therefore, while the power and THX certification of these systems ensures often spectacular audio performance in a small room with one or two listeners, they simply aren't designed to be cheap replacements for a living room system. But for secondary systems, dorm rooms, gaming, and small rooms, the performance and value a 5.1 multimedia system can provide is impressive.
My initial experience with Logitech's first generation 5.1 speaker systems was not a positive one: the subwoofer was boomy, and the main speakers added a modest amount of unwelcome colorization to the sound. Klipsch has a long history (decades of experience, actually) with the MicroTractix horn drivers used for upper frequencies in the ProMedia system, and the resulting sound was clearly superior to Logotype's first effort. However, with the Z-5500, Logitech upgraded the main drivers to "polished aluminum phase-plug" units that "combine two drivers into one--the clarity of a tweeter with the richness and fullness of a separate mid-range." Despite my usual skepticism about product marketing drivel (in a past life, I was a product marketing manager myself), in this case, the marketing copy basically has it right. The new driver array is a marked improvement. The subwoofer didn't improve nearly as much; it can play louder than before, but is still too boomy for my taste, overemphasizing sounds in the upper bass region (I'd guess in the 70 - 90 Hz range). In comparison, the Klipsch's sub is well controlled down to about 35 - 40 Hz, after which it basically disappears, which is a fair trade-off for a small system. I suspect that consumers - particularly gamers - may actually prefer the Z-5500's boomier sound, but I'm a home theater snob and wish for better accuracy. The Klipsch sub also provides more flexibile placement options than the Logitech, which comes with a prominent warning not to place the rather large unit directly next to a PC - the exact spot I suspect most users intend to use.
One area where the Logitech solidly trounces the Klipsch and edges closer to HTIB territory is the control unit. The Digital SoundTouch Control Center is quite a bit more than just a volume control. As you'd expect, it can accept multi-channel audio from a PC, but it can also do multichannel decoding itself, supports DTS 96/24, and connects to as many as 6 sources simultaneously. For some users, the flexibility and versatility will be a deciding factor; you could hook up a DVD player directly to the Z-5500 and avoid firing up the PC altogether.
Either of these systems provides a fabulous home theater experience for a PC-based system in a den, home office, or dorm room. To my ears, the Klipsch provides better sound thanks to a tighter subwoofer, but gamers who want things to go "boom" along with consumers looking for additional input and decoding flexibility may want to consider the Logitech first.
Correction: the Logitech Z-5450 has wireless rear surround speakers, not the "Z5540," as originally posted.