Product Review - Mirage OM-9 Omnipolar™ Floor-Standing Speakers - June, 2001 Jared Baldwin
Product Review - Mirage OM-9 Omnipolar™ Floor-Standing Speakers - June, 2001
In 1987 the Mirage speaker company created the original bipolar configuration. This step was a great advance in speaker technology and big leap toward creating a true to life soundstage. The next step in the evolution of speakers was to not only create an authentic soundstage, but to envelope the listener completely. This step has been taken with the advent of the Omnipolar™ speaker.
"Omnipolar technology uses room reflections to create a greater sense of realism. This realism is accomplished by recreating the same ratio of direct to reflected sound found in nature, 70% reflected and 30% direct. The front and rear mounted drivers, radiating in phase, housed in a baffle shallower than the width of a human head, tricks the brain into thinking that it is listening to a live event."
In other words, by reducing the depth of the top portion of the speaker, Mirage was able to create an even more enveloping radiation pattern from their already superior bipolar design. This is what makes the Omnipolar design (OM) of the Mirage speakers superior to standard bipolar speakers.
Jeff Percy, of Mirage,
explains the difference between bipolar and Omnipolar: "The essential
difference between bipolar and Omnipolar is that the radiation pattern of the
latter is virtually circular. Because the depth of the cabinet is so much less
than that of the bipolar speakers we made, which themselves were shallower
than competing bipolar designs, the off-axis response (and corresponding wall
reflections) are closer in spectral balance and level to the direct sound and
that reflected from those surfaces
As a reminder, with bipolar speakers, the drivers on the front and rear of the enclosure move into the enclosure at the same time, i.e., in phase. With dipolar speakers, such as ribbons and electrostatics (ESLs), the drivers move into the enclosure on one side (e.g., front), and out of the enclosure on the other side (e.g., rear), i.e., out of phase. Here are some links to Secrets animated graphics, to show you the differences in the way drivers move with bipolar designs vs. dipolar ones.
With the release of the flagship OM-1 this Fall ($25,000 - $29,000 per system - two Omnipolar panels and two powered subwoofer enclosures), Mirage is closer to filling out its current OM series which already includes the flagship OM-5 ($3,500/Pair), OM-7 ($2,000/Pair), and OM-9 ($1,300/Pair).
Immediately you would notice that the OM-9s have a summed footprint that is less than 1 ft2. This feature will ultimately allow the user to find the absolute best spot in the room without having to struggle with placing a bulky speaker. The footprint of the OM-9 is a bit smaller the OM-7 and noticeably smaller than the OM-5 since it does not have a separate cabinet structure to house subwoofers attached to the back of it.
The OM-9s have a 1" tweeter and 6 1/2" woofer on both the front and rear baffle. The rear baffle slopes from top to bottom, going from a 6" measurement at the top to 12 1/8" at the bottom. The result is a very sleek and elegant design that put it at the top of the list of great looking speakers. The OM-9s come in two finishes: piano black and cherry wood (which looks very light at first, but may darken over time). The piano black finish costs $100 more than the cherry finish in the OM-9 speakers at $1,300 ($200 more for the piano black finish in the OM-5 and OM-7 models because they are larger).
The OM series utilizes a crossover at 1.9 kHz instead of the usual 3.5 kHz, which puts decidedly less of a strain on the woofers to produce those upper midrange frequencies. The result is a sound that has a truer midrange. To provide a smoother transition between upper and midrange frequencies, the designers lowered the crossover point to 1.9 kHz from 2 kHz (OM-5s, OM-7s) to reach the goal of being less directional (more diffuse). This was incorporated due to the 2-way system being used instead of the 3-way system used in the OM-5s and OM-7s. What allows Mirage to lower the crossover point is the durability and performance of their pure Titanium Hybrid tweeter. With many tweeters of lesser quality, lowering the crossover point would affect the overall performance in a negative way, with lower sound quality and early distortion.
"Housing the tweeter in its own specially designed acoustic chamber extends its potential to an amazingly low frequency of 1.9 kHz, where it can then be crossed over to the woofer. Maintaining a low crossover point prevents the woofer from playing frequencies that might make it appear directional."
So how did Mirage get all of this sound into such a small footprint? First off they started with the same front baffle used to chisel out the OM-7 and went from there. This greatly reduced the cost of production, and we see that a great deal of the savings was passed on to the customer. Second, the OM-9s directly replaced the very popular OM 10s that had a similar footprint and the same driver compliment. However, the OM-9s boast the following improvements: Removable grilles were added to replace the sock wrap's dated design, which helps to minimize diffraction. The cabinet construction is 16 pounds heavier with thicker locking panels. The overall look has been improved with the addition of side trim panels instead of only a finished top. Also, performance has been improved by upgrading the tweeter plate, crossover, injection molded woofers, and copolymer baskets. The results helped to provide a more neutral midrange sound and deeper overall bass response.
When taking these speakers out of the box I noticed the typical and thoughtful packing that all Mirage speakers are treated with. This includes form-fitting Styrofoam packing, thick cardboard corners, and a large plastic bag that shields the speaker from small debris. They also come individually packed so you are not stuck with one gigantic box.
The high quality, dual set of gold-plated 5-way binding posts are bi-amp and bi-wire capable. Instead of taking advantage of these options, I went the traditional route and connected the speakers via gold-plated banana plugs using only the top set of binding posts. This means that I left the existing special bus bars that connect the two sets of posts firmly in place.
Under further investigation, I found that the OM-9s came in closer to 6 Ohms than the 8 Ohm rating given by the manufacturer. Not a problem, however, since most receivers or amplifiers will handle 6 Ohm loads.
Mirage recommends placing the speakers at least 1 foot ( 2' to 3' is ideal) from the back wall to maintain a deeper soundstage and to place them 1 1/2 times the distance they stand apart away from the listening position. So, if the speakers stand 6 feet apart, the ideal listening position will be 9 feet away, equidistant from both speakers. Also it is recommended not to place them an equal distance from the rear and sidewalls, to reduce unwanted acoustical problems such as room reflections. When placed properly in a room, the need for toe-in is eliminated.
These were merely the prescribed recommendations that don't necessarily apply in all real world settings. However, that's the best thing about the Mirage Omnipolar series and its ability to tame less than ideal placement or irregular room shapes. More on this a bit later . . . .
One side note - Mirage recommends 50-100 hours of burn-in time, so before you are ready take a serious listen, give them some time to loosen up.
The OM-9s (that also match the OM series) have two choices for matching center channels in the OM-C2 and OM-C3. The OM-C2 is an Omnipolar center channel using a bipolar array, while the OM C3 is a direct radiating speaker using the same Pure Titanium Hybrid tweeter and bass drivers that the OM series does. A previous article written by "Secrets" mentions that to achieve a perfect match with the OM line, the center speaker needs to be a matched Omnipolar speaker, which would necessitate the need to buy the OM-C2 that has the aforementioned drivers on the front and rear of the speaker. To make this perfect match, it will cost you twice as much as the less expensive OM-C3 (MSRP $350). The OM-C2 is an amazing center speaker and is well worth every penny, but for the current review, the OM-C3 worked just fine. In the event you spent all your money on your main speakers you could even get the Mirage FRx-Center speaker and save yourself a few more bucks (about $100), but it would probably be best just to save up for the C2 or C3.
There never seems to be any shortage of good quality reference discs when considering DVDs. I'm not sure if this made my choice of material easier or more daunting of a task. However, in the end, my choice of "A Bug's Life" and "Batman Returns" provided some great scenes for some serious listening.
Early in the movie "Batman Returns" in chapter 3, several thugs with machine guns set to take out Batman expend hundreds of rounds into an elevator. Bullets and empty shells were given the presence of flying every which way by the wide soundstage available for front effects, while the rumble of the guns was easily handled at the same time. The presence of both parts of the scene were easily distinguishable from each other, but at the same time well blended together.
Panning effects were more from over there instead of from right there, maintaining a solid front soundstage that stayed true, but gave cues of direction when needed. This was more than evidenced in chapters 31 and 32 with the Bat Boat or Bat Plane that Batman and Robin were piloting respectively. The scenes with these vehicles had some great front effects that were reproduced very well by the OM-9s.
During chapter 3 of "A Bug's Life", when the ants are collecting fruits and grains for the impending offering to the grasshoppers, I could hear individual ant crawling up and down the stocks of each plant. Later in the same chapter, a falling leaf threatens to impede the line of ants trying to deliver the harvest. The benefits of the wide soundstage were evident here, while the descending leaf floated back and forth slowly to the ground. These combined effects produced really help to suck you in to the ants' little world.
Just for kicks, I experimented a little with no subwoofer, while watching a few chapters of "A Bug's Life" and found that a sub was definitely in need (no big surprise here). If you take the advice directly from Mirage headquarters you can follow their good, better, best formula for choosing the right subwoofer for your setup. What they suggest is the FRx-12 subwoofer as good, the BPS 150 as better, and the BPS-400 as the best trio maker. My home theater setup included a single FRx-12 sub set at the 12 o'clock position. The same case for matching rears channels can be made as well with the FRx-Rears being good, OM-R2s as better, and using OM-9s all the way around as the best for rear channels.
What is definitely the most exceptional feature of the OM-9s when listening to two channels is their refined ability to fill a large space. Even more remarkable is the ability of the Omnipolar design to tame the most problematic of rooms, including vaulted ceilings or open rooms. Even while walking around a corner you may swear that one set of speakers has followed right behind you. In fact, I listened to them stand-alone in a 3-level room with a vaulted ceiling, and the end result was amazing. Wherever I walked in the room, I was pleasantly surprised at the quality of sound I was hearing. This may seem simple enough and fairly obvious, because when standing behind a pair of Omnipolar speakers, there is a set of drivers still facing you. However, take that extra step of logic and imagine what a pair of forward-firing speakers sound like from the rear.
With all of these great features, it may sound like Mirage has found the Holy Grail of speaker design and in many ways they have. However, all of these great features come with some noted if not arguable trade-offs. The issue at hand is one of precise, pinpoint imaging versus a fully encompassing sound designed to give the definitive answer to wide dispersion. It is all a matter of tastes and preferences.
Many words have been used to describe Mirage Omnipolar loudspeakers: full, neutral, warm, and rich, but I think the most accurate word may be "spacious". The sheer ability of these speakers to energize a room with sound is a great selling point. This makes these speakers very inviting to listen to.
The OM-9s seemed to take the edge off hard rock music like the Def Tones or Smashing Pumpkins. This may not sit well with those who like to turn up the volume like there's no tomorrow, but for those who like to listen to their favorite metal tunes for more than 20 minutes and still keep their interest (and hearing) because they are not burned out from listening fatigue, you'll do well with a pair of these.
Continuing with James Taylor's vocals and accompanying band from the album "Never Die Young", the OM-9 speakers came across with a very relaxed, laid back sound that Mirage has become known for. Even at low volumes, there was a pleasant amount of detail and fullness, although the music still didn't jump out at me. At times, the speakers seemed to disappear into the room, which is exactly what the manufacturer had intended. I really came to enjoy what the titanium hybrid tweeters had to offer in the realm of smooth reproduction of voices. Other “live” recordings by the Dave Matthews Band were also reproduced faithfully, keeping everything from the pick of the guitar to microphone nuances present at live events. I found that many unplugged compilations and acoustical sets seemed to be made for the likes of the Omnipolar line.
I was quite satisfied with the imaging capabilities I heard and would be compelled to make the trade for a fuller overall sound. They were not quite as laid back as say the OM-7s, with a punchier bass, and an ever so slightly brighter sound. Although punchier with its bass, comparatively the OM-9s were somewhat lacking in the lower bass range, which should be no big surprise since they are rated down to 38 Hz. As a consequence of this, at times, I really felt like I was missing the overall dynamic and impact that bass laden material has to offer.
The way it sits right now, the Mirage OM series has a tiered set of price points, starting with the OM-9s at $1,300 (cherry) and topping out with the unbelievable OM-1s (available this Fall) at over $25,000. Now, having come out with these two new speakers to add to the existing OM-7 and OM-5, Mirage has left themselves just enough room to add another speaker to this impressive line, namely, the OM-9s. The Omnipolar sound is not for everybody, and is subject to personal taste just like, for example, the sound of horn speakers. If you've been in the market for a speaker that looks at good as it sounds, you need to take a long look (and listen) to the OM-9s.
Equipment Used in this Review:
- Jared Baldwin -