Yamaha was one of the first companies to see the possibilities of soundbars (or, as Yamaha likes to call them, "digital sound projectors"). I reviewed two of their earlier-generation efforts (the YSP-1 in May 2005 and the YSP-800 in Feb/March 2006) and was thoroughly impressed. In particular, Yamaha used aggressive digital signal processing and a vast array of drivers to tackle the problem of creating spatial immersion from a line source, and the results were exceptional.

The YSP-4000 is Yamaha's newest entry in the soundbar category. It's a full-featured system containing decoders, amplifiers, and speakers. It also adds automatic room tuning, as well as full video hookups and an onscreen menu. When I say full-featured, I'm not kidding - this system has a full complement of HDMI jacks, can control an iPod, has an FM tuner onboard, and is even XM Radio-ready. (Hey, the owner's manual is 116 pages long.) In many ways, it's the most sophisticated soundbar in this roundup.

Features aside, the YSP-4000 is also a minor sonic miracle. It houses 40 full-range 1.5-inch speakers and two 4.25-inch woofers driven by 40 amplifier channels with maximum output power of 2 watts (into 4 ohms) and two channels rated at 20 watts (into 4 ohms). The speakers are used in conjunction with upstream signal processing to create and steer "beams" of sound that mimic a surround-sound field. Different modes, known as 5 Beam, 3 Beam, 3 Beam + Stereo, My Surround, and My Beam, let you choose and customize soundfields that sound best to you in your room. The system also contains Dolby Digital and DTS decoders, as well as Yamaha's Cinema DSP ambience programs. This loaded feature set is match by the YSP-4000's loaded $1,800 price tag - the heftiest among all the bars tested here.

Setup The YSP-4000 is a beefy bar with a prominent, silver metal grille that will either complement your silver flat-panel display or overwhelm it. Either way, it will add some bling to your room. Its front panel has an auxiliary input and a jack for the IntelliBeam microphone. There are also input select and volume buttons and an LCD readout. The back panel is as thick with jacks as some stereo receivers. You'll find two HDMI inputs and one output, two component-video and three composite-video inputs, component- and composite-video outputs, a subwoofer output, two analog stereo inputs, four digital-audio inputs, an XM Radio input, IR input and output, an RS-232C port, an antenna jack, and a system connector used to hook up an optional Yamaha subwoofer. There's also a port to mate Yamaha's YDS-10 iPod dock ($100).

I placed the soundbar under my TV and, taking the path of least resistance, connected it to my DVD player and display via HDMI cables. I connected my own subwoofer to the Yamaha's output. Next step was the IntelliBeam setup, which meant connecting the supplied microphone, placing it at my listening position, and then waiting while the system's test tones probed the room's acoustics. In about three minutes, the system was optimized for my space.

For fun, I also connected a YDS-10 iPod dock using the cable supplied with the dock. I was able to use the remote to control the iPod, and the on-screen display (OSD) made it easy to browse the player's contents. While you can view video and photos when using a simple remote mode, you can't see video using the more advanced OSD mode.

Music Performance Features and high-powered virtual surround are cool, but they're useless unless the speakers sound good. Fortunately, I was immediately impressed with the YSP-4000's stereo sound quality. Kashmir's vocals were properly warm and detailed, and the ultra-cool snare sound was appropriately dark and moody - though crash cymbals were a touch bright. The soundbar played extremely loudly, but it also degenerated into seriously shrill distortion. (Even though this extra gain might be useful for sources with very low output levels, the system lets you set a maximum volume, and this small chore is worth doing to muzzle any potentially loud and distorted levels.) My subwoofer handled the bass line nicely and meshed well with the bar, but when I turned down the sub's level, the Yamaha produced some decent bass on its own.

Turning to Blue Man Group, I punched in the surround modes. The first time you hear these, you'll smile. Sounds appear to originate from places where there are no speakers. Both the 5 Beam and 3 Beam + Stereo modes successfully placed images far on each end of the soundbar. The whooshing sound of the whipped boat antenna on "Sing Along" quickly swept far from side to side. Perhaps more important, the processing didn't significantly affect sound quality: Vocals and instruments remained tonally correct.

Movie Performance I punched in the 5 Beam mode and spun Superman Returns. The sequences leading up to the "death" of Superman are dense with effects, both obvious and subtle. The YSP-4000 maintained dialogue intelligibility and timbral quality, while successfully expanding the soundfield far beyond the ends of the bar, placing images almost to either side of my listening position. (Your room acoustics might give a different result.) This yielded a broad and realistic sonic space that was plenty big enough to enjoy movies with surround soundtracks. Without my subwoofer, the LFE was a bit thin but serviceable; adding the sub delivered all the low end I needed, and the overall result was excellent.

Bottom Line This is an impressive soundbar and - no pun intended - it raises the bar for any competitor. The YSP-4000 has every feature I can think of, and handles every detail of audio playback. Most important, it takes its "sound projector" name seriously and performs near-miracles in its ability to project a soundfield that reaches far beyond its physical cabinet. The soundfield isn't as immersive as with discrete speakers, but it's darn impressive. It's not an inexpensive solution - you can certainly buy a decent A/V receiver and surround speaker package for the cost of a YSP-4000. Still, if you've been considering a soundbar because of the convenience or cosmetic factors, but aren't willing to give up the perks of true surround playback, this system might well overcome your objections.