Mirage OMD-28 Surround Speaker System Page 2
The OMD-R's sealed MDF cabinet is available only in gloss black, and its grille is removable. Its two pair of input terminals are of a more conventional grade and design than the terminals on the other speakers in the system. They are recessed to accommodate wall mounting, and brackets are provided for this application.
The OMD-28s were set up in my 3200 cubic foot home theater room, well away from the side and front walls and approximately 8 feet apart on either side of my 78 inch-wide projection screen. They were toed in toward the center listening position, though because of the omni configuration of the mid-tweeter array the degree of toe-in is less significant than with conventional speakers.
The OMD-C2 center was positioned on a low stand below my projection screen, about 12-inches off the floor and tilted slightly upward toward the listening position. The OMD-R surrounds were located on stands near the back of the room.
Mirage was working on new subwoofers when they sent us the OMD-28 system, so I elected to request the speakers without a sub. As it turns out, however, most of my movie listening was done with a single (Revel B15) subwoofer engaged.
This section refers to a pair of OMD-28's auditioned in two-channel stereo, without a subwoofer, except as noted.
If, like most of us, you're used to listening to conventional front radiating loudspeakers, your first reaction to omnis can be a bit disorienting. Not that they sound like The Speaker from Planet X, or anything like that, but they do sound different. They bring more of the listener's room into play. For better or worse, your room's reverberant characteristics become part of the mix. This is always true, of course, but it's more obvious with an omni than with a traditional speaker.
All of us become accustomed to the sound of our own rooms to the point where we can almost tune it out. This is one reason why listening in an unfamiliar environment—a friend's house, a dealer showroom, a hi-fi show—can often require a period of adjustment. In a similar fashion, listening to a speaker with a radically different radiating pattern, even in your room, suddenly warps your "room tune-out" mechanism. You have to reboot it by learning to hear past the characteristics of your listening space all over again.
Fortunately this re-learning doesn't take very long. The new acoustic signature will be nearly as familiar to you as the old one after a couple of hours of listening. Only then will you be able to fairly evaluate the OMD-28's distinctive characteristics.
Mirage speakers have never been shrinking violets when it comes to bass output, and this model is no exception. Your room, system, and expectations will affect how you react to it, but at times the Mirages' bass can sound excessive, slow, and indistinct. This didn't happen often in my auditions—perhaps on 10% of the music I played. The primary offenders were complex, interwoven bass lines and, less often, close-mic'd male vocals with fundamentals that fell into just the right range to aggravate the problem. If your taste runs heavily to such material you might hear these bass aberrations more often than I did on a wider variety of recordings.
I did try a subwoofer briefly on music, and it did reduce the problem by moving the bass source to a better location in the room. But it could not completely eliminate the problem since the fullness extended into the upper bass—well above the 100Hz low pass filter I used for the sub. If your room is larger than mine, however (15.5' x 26' x 8'), or has more flexible, bass dampening walls (say, single-layer sheetrock rather than the solid lath and plaster in my built-in-the-1940s abode), the occasional bass anomalies I heard from the OMD-28 might well be a non-issue for you.
Despite its occasional excess, however, the solidity of the bass from a pair of OMD-28s was one of its most attractive characteristics. As noted earlier, I listened to music primarily with the speakers driven full range without a subwoofer. When I felt something was missing it was only because I knew what a good sub could do in the deepest reaches of the bass with some of my often-used reference material. I can't say that the Mirages went as deep with as much power at high levels as a first-class, separate sub, but on music they never disappointed me. In fact, even on their own they were often startling in with what they could do with instruments such as percussive drums and plucked double bass. The weight and authority of the speaker's entire bass range was compelling. Unlike many speakers, the OMD-28s never sounded the least bit lean or wimpy.
Listening at nearly 90-degrees off-axis to any tweeter—as is the case with the Omnipolar designs—inevitably results in reduced treble at the listener's ears. The fact that the Mirage did not sound at all dull reflects well (awful pun!) on its Omniguide diffuser. While the speaker never sounded bright, it did tend to emphasize sibilance on some close-miked vocals. But overall, the OMD-28's top end performance was impressive. High frequency transients never sounded "slow" or rolled-off. Everything was there, and in the right proportion, enhanced by the spaciousness produced by the speaker's wide dispersion pattern.
The Mirages also sound detailed without being "ruthlessly revealing" On more than one recording I heard things I hadn't heard before: a musician's fingers sliding down the strings as he plays a mandolin, his creaking chair, and a pianist grunting softly on a break between notes. But these revelations were never intrusive. In fact, recordings that sound slightly bright on other good speakers suddenly sounded right on the OMD-28s. And the recordings that sound properly balanced on other good speakers still sounded fine on the Mirage. This speaks volumes about the OMD-28's canny voicing.
The midrange of the OMD-28 ranged from satisfactory to magical, depending on the recording. I heard little of the most obvious midrange colorations such as nasality and boxiness. The only time I sensed anything amiss was when the timbre of a singer's voice excited the speaker's sometimes overactive upper bass, which reduced the subjective clarity of the midrange. This happened more often on male vocals than female—no surprise there—and on close rather than distantly mic'd recordings.