M&K S-150 THX surround loudspeaker system Page 4

Set 'em up...
With the obvious exception of the loudspeakers, the system I used to audition the S-150THX speakers was the same one I described in the Aerial Acoustics review elsewhere in this issue.

The morning Ken Kreisel came to set it up, he found my home-theater spic'n'span and me bleary-eyed. Not realizing just how complex the 150 series was, I'd put off unpacking it until late the night before—and had stayed up 'til the wee hours exploring the possibilities.

Kreisel arrived in a car packed with test gear and cool tools—my favorite was a level incorporating a laser—which made aligning speakers with the listening position a piece of cake. Truth be told, however, I found set-up of the 150THX system to be simple and straightforward. Pay attention to simple placement rules and you won't need anything fancier than a tape measure to get the job done.

Because of the angled faces of the S-150s, side-wall reflections and interference from that big ol' monitor in between the speakers were both greatly reduced. Focusing the S-150AC was also a snap, as its downward angle went a long way toward aiming it at the listening position to begin with.

The trickiest part of the procedure was determining where to put the subwoofers. We started by testing response in the front corners, but the MLSSA measurement system showed real doubling and discontinuity problems. We began to creep the woofer along the side walls and found two positions—reasonably close to the listening position, I should point out—that tested well. But after hours of testing and fiddling, the single best position for the subwoofer—according to some very expensive time-domain test gear—was in front of the closed door of the room's only entrance! Or, as my wife had predicted that morning, in the single most inconvenient place it could possibly go. We backed the subwoofer several feet along the rear wall, which allowed the door to open about two-thirds—MLSSA told us that this was almost as good, so that's where it stayed. Or should I say, they, as I stacked the second woofer on top of the first.

So, without the fancy test equipment, how close would I have come to the optimal subwoofer placement? That's a poser. I'd already begun experimenting with bringing subs out along the side walls, almost but not quite as far as the two positions that tested well near the listening position. Because of the rule of reciprocity, there is a simple way to eliminate major room nodes in subwoofer placement. All you have to do is put the subwoofer in the listening position and listen to it from the points at which you'd like to place it. You'd be amazed at how much variation there can be from point to point. I'd done this, but suffered from a failure of imagination—it had never occurred to me that the best position might be the length of the room away from the front speakers. So persevere and try everything—even if you're sure you already know the answer.

...and knock him down
I had certain preconceived notions about THX systems going into this review. Since I knew that THX specs don't guarantee "good" sound, I had begun to believe that THX don't sound good. Certainly, many of the systems I've heard did not. A number of them had a harsh, clangy sound that offended the audiophile in me. I knew that THX-certified systems could play loud—that's in the specs—but I questioned whether they could sound involving. You've got to watch those preconceptions; to follow them blindly is to wallow in ignorance.

The M&K system proved to sound natural, dynamic, and detailed. It's certainly one of the best I've ever heard. Elsewhere in this issue, I review the Aerial Acoustics surround-sound speaker system—which is also truly spectacular—but is quite a different kettle of fish. While the Aerial is accurate and dynamic, it doesn't match the M&K in those categories. Does that make the M&K "better"? In those parameters, perhaps. But it would be a mistake to discount the Aerial's strengths, which include an amiability that I find irresistible.