Polk’s new LSi M, Blackstone, and Vanishing Series speakers

LSI_StudioRendering As I perused the latest Polk speakers at the company’s Baltimore HQ last week, I felt I’d been transported to a more civilized age—to an era before the low end of the speaker market was taken over by HTiBs and soundbars, before the middle of the market withered, and before the high end drifted back to pre-WWII technologies.

The centerpiece of the introduction was the LSi M line, due to ship in January 2011. The LSi M series features no swooping lines, no flashy automotive paint schemes, and no innovations in form factor; it’s just a straightforward attempt to build some really good speakers. But for the journalists in attendance—a group that included several hardcore audio enthusiasts—that simple idea seemed sexy enough.
LSi M: the new flagship

LSi M is the first update of the top-of-the-line LS series in nine years. The line includes two tower speakers, two center speakers, a bookshelf speaker, and a surround speaker. For audio enthusiasts, these qualify as midpriced speakers: The top model, the LSi M 707 tower, will run around $4K per pair, and the bookshelf LSi M 703 will be about $1,500 per pair. (Both are pictured at the beginning of this article.)

The technical core of the line is Polk’s Dynamic Sonic Engine, a single molding that incorporates a ring-radiator tweeter and a 3.5-inch midrange driver, each in its own enclosure. The idea is that these two drivers work together in all LSi M speakers to deliver consistently clear, broad-dispersion treble and midrange, and bass drivers are added as appropriate for each model. (We’ll see this arrangement again later in the article.)

Incredibly, the 1-inch tweeter is crossed over around 1 kHz, a full octave below what would normally be considered a low crossover point. This gives the LSi M line exceptionally wide dispersion in the 1 to 2 kHz range. Normally, such a low tweeter crossover would also result in extreme distortion and rapid tweeter burnout, but Polk says its ring-radiator design can take the punishment.

The woofers on the tower speakers are unusual, “racetrack”-shaped units intended to deliver high bass output from a narrow front baffle. Although they look like passive radiators, they’re all active, and all in separate enclosures venting at the bottom through Polk’s patented PowerPort, which is intended to increase bass efficiency by quelling air turbulence at the port mouth. (Cutaway of the LSi M 707 above right.)

Prototypes of the LSi M 707 sounded exceptionally neutral, with very low sonic coloration—not bad when you consider the circuit boards for the still-being-tweaked crossovers were sitting on the floor behind the speakers. Unfortunately, I couldn’t get a sense of the stereo imaging because other journos beat me to the best seats.

Blackstone TL: the new minis

Polk carries some of the same design concepts into the new Blackstone TL series, a line of subwoofer/satellite systems. The TL series comprises three new miniature satellite speakers, each of which can be purchased separately, plus three new center speakers to match. The smallest and most affordable satellite, the $79-each TL1, is already available at Best Buy.

BlackstoneTL3_grilleon_off For this event, Polk demoed the $99-each TL2, which improves on the TL1 with better drivers and a PowerPort. The TL2 seemed to deliver excellent dynamics and bass response for its size; despite its tiny 3.5-inch woofer, it had no problem blending with the 10-inch subwoofer Polk used for the demo. That’s something few small satellites I’ve heard can do. Metal plates embedded in the molded enclosure minimize extraneous vibration.

The model you’ll probably be most interested in, though, is the “under $200 each” TL3 (pictured above left), which is pretty much the Dynamic Sonic Engine from the LSi M series. “It’s essentially the same components as in the Dynamic Sonic Engine, but not tweaked quite to the same degree,” explained Mark Suskind, vice president of product management.  Polk didn’t have a finished version of the TL3 ready to demo, but it does look promising.

Vanishing Series: the new ceiling speakers

Polk even brought the general concept of the Dynamic Sonic Engine into its new line of Vanishing Series ceiling speakers, which were shown at last January’s CES but demoed here for the first time. The Vanishing Series ceiling speakers mount their woofers in a “throat” behind a 0.75-inch tweeter and a 3.5-inch midrange driver, somewhat similar in appearance to the Dynamic Sonic Engine. The midrange angles down 15° and the tweeter 10°, so the installer can direct the sound to some extent—a great feature for in-ceiling home theater installations.

70LS_Profile All of the Vanishing Series ceiling speakers come with grilles designed to make the speaker less noticeable. The perforations are extra-fine, the bezel is only about half a centimeter wide, and the grilles are magnetic so they’re much less likely to be mangled during installation. Prices range from $229 to $549 each.

The brief demo—which included the particularly demanding cut “Jersey Girl” from Holly Cole’s Temptation CD—impressed me with the clarity of the midrange, the openness of the treble, and the tightness of the bass. I’ve tested a lot of ceiling speakers, but few that sounded this good.

F/X Wireless: the new concept in surround speakers

Last week’s event also marked the first demo of the final version of the F/X Wireless Surround, a $399 system that combines an internally powered wireless speaker and a transmitter that connects to your A/V receiver. The speaker combines four 2.5-inch full-range drivers, a 5.25-inch woofer in a ported enclosure, 100 watts of total amplification, a digital signal processor, and a 2.4 GHz receiver. The unit sits behind you on a floor or shelf, and takes the place of your surround speakers. It uses head-related transfer function (HRTF) processing to trick your brain into thinking you’re hearing wall-mounted surround speakers. The idea is that you don’t have to run any wires at all, except the ones from your A/V receiver to the F/X transmitter.

FXWirelessSuround Polk’s demo showed that the F/X does a pretty good job of sounding like a real set of wall-mounted surrounds; I only occasionally noticed that the sound was coming from directly behind me. Polk says it works with 5.1 or 7.1 systems, and will be available in October.—Brent Butterworth