Bookshelf Speaker Reviews

The voice coil’s copper-clad aluminum wire maintains low mass with good conductivity, and the wire winds around a polyimide (the stuff used to make space suits) voice-coil former that’s stable to 400 degrees centigrade. This means you should be able to play the XTR-50s Ozzy Osbourneishly loud for an extended period of time without seeing or smelling smoke emanating from behind the grilles. The voicecoil assembly itself is coupled to the aluminum dome using a fiber-dome/coil coupler that looks as though you’ve rolled the top part of the voice coil over and glued the resulting strip to the inside of the dome. It’s supposed to provide more diaphragm support and reduce resonance in the drivers. Interestingly, the drivers’ magnet assemblies protrude through the rear wall of the XTR-50’s cabinet. (Think of it as if the speaker had large, magnetic hemorrhoids.) There’s a thermally conductive gasket that seals the gap between the magnet and the cabinet, and it lets the driver use the aluminum cabinet as a large heat sink to help keep the driver cool.

The two active XTDD drivers are pressure-coupled to four dome-shaped low-bass radiators. Definitive Technology says these radiators “vibrate in sympathy with the active drivers,” but I think they’re more empathetic than sympathetic. It helps extend the speakers’ midbass response, but you’ll unsurprisingly want to use a subwoofer with the XTR50s. In my setup, which included one of the company’s tiny-but-mighty SuperCube III subs along with two pairs of Mythos Gems to make a full-blown 7.1-channel system, Def Tech recommended that I set the crossover in the bass management at 100 hertz. That’s a little higher than the traditional 80 Hz you’d use with a lot of other bookshelf speakers. If you’re going to do this, you’ll need to make sure you use a subwoofer that’s capable of reproducing more than just 60 Hz (a “one-note flatulence cannon” as Paul Scarpelli at Triad once described a competitor’s product to me). The SuperCube III is an amazingly small sub that does an excellent job of smoothly handling deep bass all the way to the upper-bass region where the XTR-50s take over. The result is a great blending of speakers and subwoofer in which you only notice the subwoofer (or actually the lack thereof) when it’s not powered on. When on, it just seems like the XTR-50s have impossibly low bass response.

Sound Quality
Of course, you always want to try out new movies when you have a new system to test. While I could talk about how well the system performed on say, Sherlock Holmes, 2012, or Avatar (no, sorry, you can’t force me to watch that one again), two older movies now on Blu-ray Disc really caught my attention. Even though I’ve seen them both more than once, I found it hard to eject either of the discs out of my PS3 in order to move on to other things. The new XTR-50s are that engaging.

The first movie was the musical, Chicago. As I watched it, I at first thought I’d write about Queen Latifah’s intro song, “When You’re Good to Mama,” but what really blew me away was the intense “Cell Block Tango.” This song, full of snaps, pops, and Ciceros, is at times about as dynamic and in your face as any you’ll see on the stage or screen. Two things become immediately apparent. One, the Definitive Technology tweeter—similar to the one that the Mythos ST speakers use—is as smooth and sweet as I remembered it being. With a lesser tweeter, the sibilants that fill the performance could slice through your eardrums, but not here. If your body could take the driving beat, you could listen to the song all day and not suffer any ear fatigue. The second thing is the XTR-50’s dynamic capability. It’s amazing to me that a speaker this thin—remember, we’re talking about speakers that are only 1.5 inches thick—can handle such dynamics without bottoming out or cracking up. On the opposite end of the acoustical spectrum, “Mister Cellophane,” a slow solo sung by John C. Reilly, shows how revealing the XTR-50s can be with less dynamic source material.

Less dynamic, more bizarre, and equally engaging is how I would characterize the other movie the XTR-50s brought back to life for me: A Scanner Darkly. Surround sound isn’t this movie’s forte, but gritty, slipping, shifting dialogue is. The XTR-50 worked flawlessly as a center channel. It brought out the differences in the drug-influenced voices and their emotions. Likewise, for stereo music, as I was listening to “Promises,” a cut from Lyle Lovett’s The Road to Ensenada CD, the same crystal-clear vocal detail was there at the beginning of the track when Lovett takes a breath just before he starts to sing. The XTR-50s make it sound like he’s in the room directly in front of you. The more dynamic “It Ought to Be Easier” would sound a bit fuller playing on a full-fledged floorstanding speaker (such as the Mythos STs), but the performance for an on-wall speaker was outstanding.

Sade’s voice, on “Morning Bird” from Soldier of Love, is clear, clean, and layered in the center over the accompanying piano and percussion. Although it can sometimes happen that you’ll hear a speaker straining to reproduce Sade’s unique vocal characteristics, the XTR-50s showed none of that. With the disc’s title song, the SuperCube III proved its mettle once again (I reviewed it several years ago as part of a Mythos Gem–based system). The entire system—XTR-50s, SuperCube III, and two pair of Gems—came alive with The Killers’ “Human” video on one of Dolby Lab’s Blu-ray demo discs. The active surround mix showed off how well the Gems blend with the XTR-50s.

Conclusion
There’s no doubt about it. Flat-panel HDTVs rule the day. I feel certain that we’re not in danger of folks suddenly deciding they want big, bulky picture-tube TVs anytime soon; and the days of feeling like you’re slumming it if you don’t live in a 5,000-plus-square-foot house aren’t likely to return, either. That means slim speakers will continue to grow in popularity—whether or not they sound good. In this particular case, the beauty of the new Mythos XTR-50 is more than skin deep. At the moment, I don’t think there’s a better combination of size, appearance, performance, and price in any other on-wall speaker you can buy. The XTR-50’s beautiful styling is apparent upon first sight, but it doesn’t take much listening time to realize that this fabulous-looking speaker sounds fabulous as well. It’s a stunner that will steal the show, regardless of how good your flat-panel HDTV is. The Definitive Technology crew may have a new parent, but they’re still the boss.