This is a loooong post, but I figure you're looking for all the info you can find.
Before I start, here are some useful reviews of the OMD-28:
-- TAS review by Chris Martens, who bought the review pair and made it his new reference
-- Soundstage review by publisher/editor Doug Schneider
-- UltimateAVMag review by Thomas J. Norton. The measurements are a poor indication of the quality of this speaker, as they are taken quasi-anechoically while the speaker is designed to interact with the room to achieve a flat power balance. The Manufacturer's comments bear reading; they match my personal experience in tonal balance and optimum in-room placement.
I have been a Mirage user for over 12 years, starting with a pair of M5si's anchoring an all-Mirage 7.2 HT surround system in the family room. I have a pair of the OMD-28's little brother, the OMD-15, in a 2-channel system in the living room, which is my primary music-listening system. The OMD-15s replaced a pair of 1st gen Omnisats w/matching LF-150 sub. I have Mirage speakers from their bipolar, Omnipolar, 1st gen Omniguide, and 3rd gen Omniguide product lines.
The Omnisat satellites I bought in 2005 proved to be a revelation. I had just gotten married at home 4 months earlier, featuring live music in the same living room. The Omnisat principle energized the room and achieved very realistic tonal balance, timbral balance, and soundstage--just like live musicians in the room.
Originally the Omniguide was designed to provide a forward-bias omni pattern in a tiny speaker. But the design proved so effective that it took over Mirage's entire product line from top to bottom, including their new flagship, the OMD-28. The Omniguide showed such potential that Mirage started developing a $20K statement speaker around the design, but new owner Klipsch yanked the plug on that project and instead came out with their own $20K statement speaker.
The OMD series has a very realistic, transparent, neutral midrange with focused, real-sounding vocals. The singer doesn't sound like she's standing in a hole as with so many "audiophile" speakers with a purposely recessed midrange. Nor is the vocalist in your face as a '60s-era horn-based studio monitor. Perspective is just right, and duly fast and transparent.
Compared to the previous gen (e.g., OM-9) bipolars, the OMD series throws 60% (or a little more) of the sound directly at the listener. Compared to the first generation Omniguide speakers, the OMD-series baffle surrounding the omniguide assembly is larger, which seems to throw more sound forward and focus the vocals better. This 60/40 bias was based on Mirage's extensive research into creating a soundfield that sounds most like live music to the greatest number of listeners. The new OMDs have far more direct, precise midrange location than either the old omniguides or the earlier generation bipolars.
The OMD series also features a highly effective mid- and woofer innovation--the ribbed elliptical woofer surround that enables the bass driver to maintain linearity over a longer cone excursion. My OMD-15s put out astonishing bass speed, clarity, extension, and fullness from a couple of 5.5" active drivers, and nail the depth and fullness of orchestral concert bass drum, timpani, and large gong. Yet when playing fusion jazz or with a nimble bassist the OMD's bass is also appropriately quick.
As for soundstage, it's just like if you were at a club. At center stage you hear a balanced, detailed presentation. Move to the side, the soundstage remains where it was, while you hear it from an off-center perspective. Because of the omni characteristics, you hear plenty of the far channel in perspective with the near.
The speakers also scale very well. Put on solo voice or solo voice with guitar, and it hangs a realistic-sized image in space between the speakers. Then, when you go to 4-piece jazz combo to choir to big band to full scale 100-piece orchestra, it scales up accordingly. By the time you get to 100-piece orchestra, the soundstage takes over all room space even with and behind the two speakers.
The OMD series is far easier to drive and more transparent than the old MXsi series, requiring less heroic amplification and cabling to get them to sing. I'm driving my OMD-15s with a 100wpc Onkyo A-9555 integrated, bi-wired with some $100 Belkin OCC speaker cable. The OMD system totally kicks the M5 system with its 150wpc amp and $1500 PS Audio bi-wire cables. The OMD's clarity, transparency, realistic soundstage, tonal balance (not as dark), and dynamics all trump the M5si on significantly less power. Yet the OMD-15 is rated to accept 250w. I wonder what that would yield, because it sounds awfully good with the Onkyo integrated. Maybe they just like switching amps?
As for putting the omniguides to work in surround sound, that's also great. When I replaced my living room Omnisats with the OMD-15s, I installed the Omnisats as rear surrounds in the HT system. I think it's the best way to implement a 5.1 or 7.1 system. The broader soundfields combine to make a completely enveloping soundfield with no gaps or obvious handoffs from one speaker to the next. Yet when the soundtrack calls for pinpoint location they deliver.
Can't say enough good about the OMD series. They broke in easy, but 10 months later I'm *still* hearing things in my recordings i hadn't noticed before. I'd love to upgrade to a Phonomena phono stage and a NuForce stack of separates to see just how resolving the speakers are.
The performance of the OMD-28s should significantly better the OMD-15 in every way: The cab is larger and the midrange and bass drivers are made with lighter, more rigid materials. But they're also less sensitive and would demand better amplification. With the larger cab and woofers, the OMD-28s stand to perform their best with a high current powerful amp with a high damping factor. A powerful switching amp should also do the trick.
Before I start, here are some useful reviews of the OMD-28:
-- TAS review by Chris Martens, who bought the review pair and made it his new reference
-- Soundstage review by publisher/editor Doug Schneider
-- UltimateAVMag review by Thomas J. Norton. The measurements are a poor indication of the quality of this speaker, as they are taken quasi-anechoically while the speaker is designed to interact with the room to achieve a flat power balance. The Manufacturer's comments bear reading; they match my personal experience in tonal balance and optimum in-room placement.
I have been a Mirage user for over 12 years, starting with a pair of M5si's anchoring an all-Mirage 7.2 HT surround system in the family room. I have a pair of the OMD-28's little brother, the OMD-15, in a 2-channel system in the living room, which is my primary music-listening system. The OMD-15s replaced a pair of 1st gen Omnisats w/matching LF-150 sub. I have Mirage speakers from their bipolar, Omnipolar, 1st gen Omniguide, and 3rd gen Omniguide product lines.
The Omnisat satellites I bought in 2005 proved to be a revelation. I had just gotten married at home 4 months earlier, featuring live music in the same living room. The Omnisat principle energized the room and achieved very realistic tonal balance, timbral balance, and soundstage--just like live musicians in the room.
Originally the Omniguide was designed to provide a forward-bias omni pattern in a tiny speaker. But the design proved so effective that it took over Mirage's entire product line from top to bottom, including their new flagship, the OMD-28. The Omniguide showed such potential that Mirage started developing a $20K statement speaker around the design, but new owner Klipsch yanked the plug on that project and instead came out with their own $20K statement speaker.
The OMD series has a very realistic, transparent, neutral midrange with focused, real-sounding vocals. The singer doesn't sound like she's standing in a hole as with so many "audiophile" speakers with a purposely recessed midrange. Nor is the vocalist in your face as a '60s-era horn-based studio monitor. Perspective is just right, and duly fast and transparent.
Compared to the previous gen (e.g., OM-9) bipolars, the OMD series throws 60% (or a little more) of the sound directly at the listener. Compared to the first generation Omniguide speakers, the OMD-series baffle surrounding the omniguide assembly is larger, which seems to throw more sound forward and focus the vocals better. This 60/40 bias was based on Mirage's extensive research into creating a soundfield that sounds most like live music to the greatest number of listeners. The new OMDs have far more direct, precise midrange location than either the old omniguides or the earlier generation bipolars.
The OMD series also features a highly effective mid- and woofer innovation--the ribbed elliptical woofer surround that enables the bass driver to maintain linearity over a longer cone excursion. My OMD-15s put out astonishing bass speed, clarity, extension, and fullness from a couple of 5.5" active drivers, and nail the depth and fullness of orchestral concert bass drum, timpani, and large gong. Yet when playing fusion jazz or with a nimble bassist the OMD's bass is also appropriately quick.
As for soundstage, it's just like if you were at a club. At center stage you hear a balanced, detailed presentation. Move to the side, the soundstage remains where it was, while you hear it from an off-center perspective. Because of the omni characteristics, you hear plenty of the far channel in perspective with the near.
The speakers also scale very well. Put on solo voice or solo voice with guitar, and it hangs a realistic-sized image in space between the speakers. Then, when you go to 4-piece jazz combo to choir to big band to full scale 100-piece orchestra, it scales up accordingly. By the time you get to 100-piece orchestra, the soundstage takes over all room space even with and behind the two speakers.
The OMD series is far easier to drive and more transparent than the old MXsi series, requiring less heroic amplification and cabling to get them to sing. I'm driving my OMD-15s with a 100wpc Onkyo A-9555 integrated, bi-wired with some $100 Belkin OCC speaker cable. The OMD system totally kicks the M5 system with its 150wpc amp and $1500 PS Audio bi-wire cables. The OMD's clarity, transparency, realistic soundstage, tonal balance (not as dark), and dynamics all trump the M5si on significantly less power. Yet the OMD-15 is rated to accept 250w. I wonder what that would yield, because it sounds awfully good with the Onkyo integrated. Maybe they just like switching amps?
As for putting the omniguides to work in surround sound, that's also great. When I replaced my living room Omnisats with the OMD-15s, I installed the Omnisats as rear surrounds in the HT system. I think it's the best way to implement a 5.1 or 7.1 system. The broader soundfields combine to make a completely enveloping soundfield with no gaps or obvious handoffs from one speaker to the next. Yet when the soundtrack calls for pinpoint location they deliver.
Can't say enough good about the OMD series. They broke in easy, but 10 months later I'm *still* hearing things in my recordings i hadn't noticed before. I'd love to upgrade to a Phonomena phono stage and a NuForce stack of separates to see just how resolving the speakers are.
The performance of the OMD-28s should significantly better the OMD-15 in every way: The cab is larger and the midrange and bass drivers are made with lighter, more rigid materials. But they're also less sensitive and would demand better amplification. With the larger cab and woofers, the OMD-28s stand to perform their best with a high current powerful amp with a high damping factor. A powerful switching amp should also do the trick.