November 2009
BG Radia BGX-4850 In-Wall Subwoofer System - It’s What You Don’t See
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When I first heard that Igor was working with Laurie Fincham (THX’s chief scientist and VP of research and development) on a project to develop the world’s first THX Ultra2–certified in-wall subwoofer, I thought maybe he’d been swigging from one of those vodka bottles that were meant for me. After all, THX Ultra2 certification is for products that are designed to be used in large home theater rooms, typically around 3,000 cubic feet with a viewing distance of approximately 12 feet. It’s tough enough to design a free- standing subwoofer for that kind of application. Coming up with an in-wall version that doesn’t require significant modifications to the wall—requiring 8-foot-tall back boxes or stud relocation, for example—seems like it would be darn near impossible.
Or so you might think. It turns out that, after a longer period of time than they originally anticipated, Messrs. Fincham and Levitsky have come up with just such a thing. Better than that, they’ve come up with an in-wall subwoofer that can hold its own against the best subwoofers of any configuration on the market. And they’ve done it in a form factor that’s surprisingly simple and amazingly easy to install, in either new or existing construction.
Dead on Arrival BG Radia’s BGX-4850 system consists of four BGX-S12B subwoofer modules and a BGA-2104 subwoofer amplifier. Invariably, anyone who looks for the first time at the naked BGX-S12B modules before they’re hidden in the wall will experience a definite “What the…?” moment. The dark-gray modules look more like high-efficiency space heaters or some extremely bogus ionic air purifiers than they do subwoofers. Of course, unless you’re an uber-techie and decide to attach them to the wall sans covering (which, by the way, you could do, and they’ll work fabulously), your only chance to marvel at their unique design will be as you or your installer attaches them to the studs in the wall. Each module measures 14.5 inches wide by 26.75 inches high and is only 3.5 inches deep (more on this a bit later). This means they will easily fit in any standard 2-by-4 studded wall.
You’d expect to find a large single driver or, as is the case with some other in-wall subs, a powered driver paired with a passive radiator. Instead, each BGX-S12B module contains a dozen 4-inch “micro-precision” woofers—yes, 12 4-inch woofers, not four 12- inch woofers. Each one is sealed in its own individual chamber or pod. The pods are arranged in balanced pairs that fire in phase directly toward each other. Sound exits through a narrow channel that runs down the center of the module between the opposing drivers. BG claims that the 48 drivers included in the four modules have a total combined radiating area that’s equal to two 18-inch drivers. (My math says it’s actually about 20 percent more area than two 18-inch drivers, but I’ll take BG’s word for it.)
The unique design is part of a new technology from Fincham and THX called THX Balanced Bassline. In addition to generating a lot of bass, the tightly coupled opposing drivers inherently cancel vibration. Levitsky tells me that the subs reduce vibration even further by using small, specially shaped woofer pods made out of a glass-reinforced composite material. The design minimizes internal standing waves and shifts mechanical structural resonances much higher than the operational range of the subwoofer, and it’s amazingly effective. Even with the lowest bass information, the drywall around an installed module vibrates no more than any other spot of drywall in the room. Impressive as that was, I was even more amazed when I laid a module on its back on the floor and placed a filled wine glass on one of the pods. (In order to protect our new carpet, I used water in the glass rather than wine—just in case BG’s claims were slightly exaggerated.) With the sub playing at near painful levels, the filled glass barely budged.
Wall-Easy The 3.5-inch-deep BGX-4850 subwoofers easily fit in a standard wall without any special modifications, dog ears, or heavy-duty clamps to hold the enclosure tightly against the drywall. In fact, the subs will be a breeze to install for anyone who’s ever held a drywall saw and a cordless screwdriver (not necessarily at the same time). Even if you don’t install the system yourself—which is entirely doable—it’s still a bonus because the less time it takes your installer to install the sub enclosures, the lower your labor bill will be.
Inappropriately named NCBs (new construction brackets) are required for retrofit installations as well as new construction. Two grille options are available, and your choice depends on whether the install is a retrofit or new construction. For new construction, the NCB and sub enclosure are installed before the drywall. When the wall goes up, the contractor cuts a hole in the drywall around the 7-inch-wide protective cover on the front of the enclosures. After the wall has been painted, the cover is removed and replaced with a narrow 7-by-28-inch grille. In a retrofit application, the NCB is used as a template to cut the hole in the drywall. After you secure the NCB to the studs with four screws, you’ll screw the module into the NCB. After the speaker wire is attached, a 15-by- 29.5-inch grille snaps into place. This latter option isn’t as stealthy an install as the slender 7-inch grille, to be sure. However, since you don’t need to make any other modifications to the wall, it’s a decent trade-off.
I’m sure by now, you’re wondering, “How do they manage to fit 12—or, for that matter, even two—4-inch woofers sideways in a module that’s 3.5 inches deep?” That’s such a good question, I asked it myself. It turns out that the 3.5-inch depth spec is the installed depth. The remaining half-inch or so of the drivers extends through the opening in the drywall, and the grilles bow outward slightly to provide a smidgen of extra room.
All Amped Up The system’s BGA-2104 power amplifier/controller is a standard rack-mount-sized component that generates two channels of 1,100 watts each. Each amplifier drives two modules connected in parallel. Since all processing and amplification happens in the BGA-2104, a single run of speaker wire is all you’ll need to connect the subwoofer modules to the amp. In terms of aesthetics, it has a basic LED display panel on the front with a large rotary encoder knob next to it. While it’s not ugly, the lackluster look may make you relegate it to one of the less prominent shelves in your rack. The main menu functions (including level, mode, crossover, phase, and input) are all accessible from the front panel via the encoder knob. Anyone who has ever worked with a subwoofer will find it easy to set up, but the amp is somewhat slow to respond after it receives a menu command. The included creditcard-style IR remote control lets you turn the sub on or off—the system does have auto signal sensing capability with three sensitivity settings. You can also change the volume level and switch between user-adjustable Music and Movie preset modes. There are also power and mode triggers. It’s unusual for a subwoofer this expensive to not include some sort of automatic room correction circuitry, but according to BG, it’s not that necessary thanks to the acoustic benefits of the four separate sub modules. (More on that in a moment.)
The most frustrating part of the installation will probably be connecting the speaker wires to the outputs on the back of the subwoofer amplifier using the two included Neutrik SpeakOn connectors. Levitsky says BG likes to use these locking speaker connectors because they provide a highly reliable connection that protects against electric shock and shorting. That’s correct, but it still doesn’t make them any easier to terminate. Fortunately for me, Levitsky offered to do the wiring. However, I did have to let him borrow a tiny screwdriver to do the job.
The Why Four and the Where Four If the amp has only two channels, what’s up with having four modules? Couldn’t BG have just made the modules a little taller, added a few more drivers, and called it a day using only two?
First of all, in order to achieve the volume levels that are required for THX Ultra2 certification, the system needs driver surface area. (BG also makes the $4,995 BGX- 2450 that includes the same amp and two of the sub modules. This configuration is THX Select2 certified and may be fine in a smaller room and satisfying at lower listening levels. ) However, volume is only part of the story.
As Levitsky explained, if you’re a single, action-movie junkie with no prospects of romantic involvement any time soon, put your subwoofers in one corner of the room. This will generate the maximum amount of bass and the most complaints from the neighbors. Unfortunately, this setup will typically be annoyingly inconsistent in terms of output from seating position to seating position. Equalization can help smooth out the response curve, but only for one specific listening location in the room.
Thanks to research done by Floyd Toole and others, one simple solution to the problem of uneven bass throughout a room is to use multiple subwoofers positioned on opposite walls (if possible). While two is good, four (although more expensive) is even better—thus the choice of four modules for the BGX-4850. In addition to being able to produce the amount of output required for a large room, properly installing the modules on opposite walls provides a smoother overall frequency response and greatly reduces variations in output from seat to seat.
The locations where I could install in-wall subwoofers in my theater weren’t ideal, but after we finished dialing in the system, the BGX-4850’s performance was about as ideal as you could want. To prove the point about the value of multiple sub locations, Levitsky captured the response curves in the room with one, two, and then all four subwoofers in action. We didn’t need to see the graph because we could hear the differences. It was especially interesting to see the results on paper. There’s no doubt of the benefit from having four woofers.
But how do you know where the best locations in your room are? In theory, you’d place one sub in the center of each wall, or one in each corner. Since the BGX- 4850 modules are acoustically self-contained, you can easily move the modules to different places in your room and listen to the system in order to find the best spots. Unfortunately, you can’t do this if you’re building a new home and the modules need to be installed before the drywall goes up. Then it’s best to rely on theory and your custom A/V designer’s judgment.
What a Blast Earlier this year, my wife and I were lucky enough to be at Cape Canaveral for a launch of the Space Shuttle. Even from our vantage point five miles away, the sound of the fury of the launch was damn impressive—at one point, it even elicited a stunned “Whoa!” from most of the assembled geeky types on the crowded beach. Of course, having seen and heard the real thing, and being prompted from the hoopla surroundng the 40th anniversary of the first moon landing, I decided I needed to find out how well the BGX-4850 could handle Hollywood’s version of a launch in Apollo 13.
I have to admit that I always get a lump in my throat when I watch Apollo 13. It’s partly because I’m old enough to barely remember it happening and partly because it was such a tremendous human achievement. When I watched the launch sequence, the lump in my throat was joined by quivering in the rest of my body as those 48 little woofers in the BGX-4850 flooded the room. Eager for more, I dug out my three-disc set of actual Saturn V launch footage taken by NASA cameras, some of which were located right on the launch pad. Visually, the real thing isn’t as spiffy as the theatrical version (although I think it’s more awe- inspiring); but hearing the actual audio, including a bird or two in the background before all hell breaks loose, is almost frightening. The BGX-4850 system was superb in its reproduction of the sonic fury. However, at one point, while I had the volume up a bit past the point of comfort, the system’s limiters kicked in. But I only know this because I happened to be looking at the amp’s display when it happened. Audibly, the limiter circuit’s action was imperceptible.
Other than the time I crashed an Apache helicopter in an Army training simulator, I have very little experience with real military helicopters. I feel I have the experience, though—and the emphasis is on the word feel—after watching numerous helicopter-happy scenes in Transformers. A lesser sub would certainly be able to pressurize the room with each pass of the rotors. But the BGX- 4850 is cleaner and tighter, so you get the sense of blades slicing through the air rather than the heavy slaps you’d usually hear.
Normally, I’d spend the rest of the day marveling at the plot twists and turns in Transformers, but as it happens, sometimes I like to listen to music. As with flying helicopters, I’m no expert on playing the bass guitar—my kids won’t even let me hold our PS3 Rock Band bass guitar controller—but I think I’m on pretty solid ground when I say that the three bass players who make up S.M.V., Stanley Clarke, Marcus Miller, and Victor Wooten, are pretty good. (That ought to qualify as the understatement of the year, if not the decade.) As I listened to the long-awaited Thunder disc, I quickly realized that the BGX-4850 is as musical and nuanced as it is powerful. With nothing else in the recording to overshadow the textures of the two bass guitars in the hands of Wooten and Miller jamming on “Classical Thump (Jam),” for example, I heard each hand slap, as well as the way the sub comfortably and cleanly reproduced the power of the initial release of the guitar strings. Reviewers often use the term effortless to describe speakers, and the word applies here, except that it doesn’t go far enough. It’s not so much that the sub’s performance gives a sense of ease as much as a sense of “is.” It’s hard to think about the sub as being separate from the music. It’s just as apparent with music a little more outrageous, such as Flight of the Cosmic Hippo (which included Wooten as part of Béla Fleck & the Flecktones). Despite the extension and duration of some of the low bass notes, the BGX-4850’s output always seemed natural. Cuts from Big Bad Voodoo Daddy’s Live recording jumped with the same enthusiasm.
Conclusion I shouldn’t have praised the BGX- 4850 as much as I have, as it has one seriously large drawback. The BGX-4850’s $6,995 price tag means that I can’t afford it. A lot of you probably can’t afford it, either. (If you can afford it, did I mention that I hate you?) It’s terribly sad because there’s no doubt in my mind that the system is well worth the money. It’s not only the best in-wall subwoofer I’ve reviewed, it’s one of the best subwoofers of any configuration that I’ve heard. Knowing that the BGX-4850 is out there will always make me look at my current subwoofer and muse on how amazing things could be if we didn’t have kids, tuition, a mortgage, and all the other things that suck the money out of our bank account. Curses on you, Levitsky and Fincham! You’ve ruined just about any system I’ll ever own. I think I’ll open that bottle of vodka now.
Let’s play a word association game. If I say “state-of-the-art subwoofer,” what thoughts first come to your mind? My bet is that you are picturing a big, honkin’ precision-made woofer (or two) loaded into a beefy, bank-vault-like enclosure and that is powered by a take-no-prisoners amplifier with enough output to propel a hybrid car. Well, apart from the amplifier part of the equation, let me tell you that the BGX-4850 subwoofer system ($6995) is nothing like that.
Flying in the face of tradition, Fincham and the BG Radia team have developed a multi-component woofer system comprised of four extremely compact yet very high output in-wall woofer modules that are—get this—inherently vibration canceling, plus an outboard controller/amp module to power them. Interestingly, Fincham never saw the in-wall aspect of the system as a performance-limiting factor. On the contrary, he felt the size constraints of an in-wall sub compelled him to think—quite literally—“outside the box” to create new woofer technologies that offer a fundamentally better-sounding way of reproducing bass frequencies. To appreciate the true character of this BG Radia woofer system, then, don’t think of it as an in-wall product, per se, but rather as a world-class sub that also just happens to support in-wall mounting.
Specifically, the BGX-4850 subwoofer system is meant to address five specific design goals:
As the THX/BG Radia press briefing came to a close back in 2007 I expected that a production-release version of the BGX-4850 system would appear within a few months, but it was not to be. When manufacturers are chasing state-of-the-art performance it can take longer than you’d think to get those final few product details just right, which was certainly the case with BG Radia’s new super woofer. Trade shows came and went yet the final production version of the BGX-4850 system remained tantalizingly beyond reach—until just recently. But as you’ll see in a moment, it was worth the wait.
Consider this subwoofer system if: you judge subs by their sound, not by their looks. (BG’s system looks fine, but—in in-wall form—is essentially invisible). This system performs exactly as advertised; it provides high output, deep bass extension, lightning fast transient response, great pitch definition and timbral purity, and evenly balanced bass output all over the room. Unorthodox though it may be, this is one of the two or three best subs I’ve heard at any price.
Look further if: you want massive “trophy subs” to show off to your buddies (the BGX system duplicates the output of two conventional 18-inchers, but is low on “bling factor”). Look further, too, if you are cost conscious or require an in-room solution (BG’s in-room enclosures won’t be available ‘til later this year). The only serious omission is lack of a built-in room/sub EQ system—a touch we would certainly expect in a woofer system in this price/performance class.
How can this be? The answer involves two important BG Radia design decisions. First, by using many small bass drivers (48 x 4-inch units) rather than a few much larger and more massive woofers, BG Radia has produced a woofer that not only moves huge quantities of air at low frequencies but that—quite remarkably—offers flat frequency response all the way up to about 4.5kHz (a claim few if any other subs can make with a straight face). Second, BG Radia’s THX Balanced Bass Line cabinets effectively eliminate problems with cabinet resonance, which can be a huge problems with many box type subs. Even when the BGX-4850 is belting out powerful deep bass, you can put your hands on the BG woofer enclosures and pretty much feel, well, nothing at all. Though I admit that it initially seems a bit strange, it’s a wonderful thing to experience powerful and articulate bass with no cabinet shakes, quakes, or bad vibes of any kind.
Planar ribbon drivers employ an ultra-thin, low-mass diaphragm or membrane coupled with strong Neodymium magnets to move air and thus create sound. The low-mass of the diaphragm is not only lighter but has a larger surface area than a dome or a cone midrange or tweeter, which gives them the ability to move more air quickly and uniformly. The output of a planar ribbon driver is evenly distributed over the entire radiating surface, which results in no wave cancellation, diaphragm break-up or resonances. The flat radiating surface also results in a coherent wavefront with even dispersion. The result is exceptional clarity, accuracy, detail and a certain sparkle in the high-end that sets them apart sonically from standard cone drivers.
Ribbon or planar drivers are not new – they were first introduced in the 1930s, but with mixed results and uncertain reliability. New diaphragm materials, stronger magnets and improved manufacturing techniques have made ribbon drivers as reliable as cone drivers and with the ability to create realistic output levels needed for today’s dynamic music and movie content. The sound wave created by ribbon drivers also provides wide horizontal dispersion for a broad listening area, ideal for a home theater or stereo system.
I noted in my review of the R-800s that the ribbon drivers sound outstanding, particularly with percussion instruments, such as the piano. They have a smooth and strikingly realistic sound quality with excellent transient response due to the low mass of the diaphragm. Likewise, vocals have a palpable in-room presence and uncolored sound quality that is hard to match. Subtle musical details that are otherwise lost are more easily resolved. Listening to a ribbon driver brings the listener closer to the live performance. All of these characteristics lead to excellent imaging and soundstage characteristics. They also reveal weaknesses in recordings, but that’s kind of interesting, too.
In many respects, the Z-92s are similar to the R-800s. Their clarity and high-definition qualities present a clean, uncongested midrange presence and a high-end that resolves details that otherwise go unnoticed in music and movie soundtracks. The quick attack of the ribbon drivers results in very good transient response. The guitar in Acoustic Alchemy’s “One for the Road” (GRP Records) sounds snappy and sharp like the pluck of a guitar string should sound. The R-800s have a taller image and bigger sound stage than the Z-92s, but that’s to be expected given their height.
I thought the two 6.5-inch woofers in the Z-92s sounded tighter and punchier than the two 8-inch woofers in the R-800s, though not as deep. The smaller size of the woofers in the Z-92 gives them a quicker, tighter response. When placed correctly in the room, the bass in the Z-92s is well balanced with the rest of the system.
It’s a trick question. The R-800s offer an unbelievable sound experience, but it’s not realistic to compare a floorstanding tower speaker with an eight-foot tall speaker with 22 ribbon drivers. So, I give the Z-92s a Guide rating of 4 1/2. The ribbon drivers are outstanding and the Z-92s produce tight, well-defined bass response. They deserve serious consideration for a mid-priced to high-end stereo or home theater system. I can’t give them a five rating because that designation is reserved for the R-800s. Check out the BG Corp.website to locate a dealer near you. Good listening!
Specifications
About four years ago I reviewed a surround system based on BG’s first Z-series speakers and found it to be very good, though with the minor caveat that you could sometimes hear discontinuities in transient speed and resolution between the speakers’ blazingly fast planar ribbon tweeters and audibly slower conventional woofers. What would have helped, I thought at the time, was a planar ribbon midrange driver to help bridge the gap in the middle. And as it turns out a planar ribbon midrange driver is precisely what BG Radia provides in its newest Z-series models—the Z-92 and Z-62. In theory, these speakers should offer greater clarity from top to bottom and a more seamless blend between drivers, and to test that theory I decided to review a surround rig comprised of two Z-92 floorstanders (used as L/R main speakers), three Z-62 L/C/R speakers (used in the center channel and L/R surround positions), plus one of BG Radia’s 210i subwoofers. How does the complete package sound? Read on.I've reviewed many excel- lent in-wall speakers, but none quite like the new Radia R-800 in-wall speaker from BG. With 24 drivers in each speaker, this giant stands almost 7 feet tall and is clearly designed for extreme listening—extremely satisfying listening, that is. Each speaker has two 8-inch woofers mounted at the top and bottom, six Neo10 planar-ribbon midrange panels, and 16 Neo3PDR planar-ribbon tweeters in a vertical-line array pattern. An outboard amplifier, the BGA-2500, which is included with a pair of Radia R-800s, powers the two woofers.
This was an exceptionally ambitious review, but one I was eager to start. My first preview of the Radia R-800s at CEDIA 2005 in Indianapolis was very convincing. I was glad to have the assistance of Ed Jaeger, president of BG, and Fred Yando, vice president of sales, to help me install and set up the Radia R-800 speakers. In fact, I couldn't have unpacked, moved, or installed them in the walls without their help. Beware, because, once they were installed, their appearance in my living room was formidable. If the room didn't have high ceilings, they wouldn't have fit as well as they did.
If their appearance is formidable, their sound quality is awe-inspiring. I've reviewed other BG in-wall speakers and was pleased with the sound quality, which entailed a clean, open midrange and excellent high-frequency detail. But the Radia R-800s define a new standard. Almost immediately, they produced a you-are-there sense of midrange clarity and presence, as well as high frequencies that were pure and uncolored. Each instrument and vocal element was easy to distinguish from others in the soundstage. Detail and definition was outstanding, with a strong center image. Since these speakers were shipped fresh from the production line, their sound quality continued to improve after several hours of breaking in.

In particular, vocals were strikingly clear, creating a feeling of immediacy and intimacy with the music, as if I were listening to a live performance. With a new recording from Renée Fleming, Haunted Heart (Decca Records), the speakers revealed every detail and nuance in her voice and breath, which helped convey the sad emotions present in many of the songs. The piano sounded as if it were in the room, with a solid foundation of bass and newfound clarity in the midrange and higher frequencies. The Voices Unbound DVD-Audio (AIX Records) by Zephyr showcased two of the best examples of vocal alacrity in the Radia R-800s: "Now Is the Month of Maying" and "Le Chant des Oyseaux." They are a cappella recordings in the round, with a single microphone placed in the center of a ring of vocalists. When I played these tracks in multichannel mode with the rest of the speakers in my system, the voices' transparency and dynamic range were amazing, as if I were seated in place of the microphone. The sound was enveloping, detailed, and accurate.
The Radia R-800s do what any good speaker should: They allow you to hear the music, not the speaker. They are incredibly transparent. Many speakers force you to listen—they have a so-called in-your-face sound—but the Radia R-800s let you listen. They connect you with the music and let you pick out various details and elements of a recording as you wish. There are only two other speakers I've had in my home that impressed me this way: the KLH Model 9s (electrostatic speakers made in the 1950s) and the Dahlquist DQ-10s (phase-coherent speakers made in the 1970s).
Don't be surprised if the Radia R-800s reveal weaknesses in some recordings. As much as I enjoy listening to older discs, these speakers bring out the best and worst qualities in a recording. This was evident in Django Reinhardt's duet with Stephane Grappelli in a 1940s-era monaural recording, Djangology (Snapper Music). As you might expect, the lack of dynamic range was immediately exposed. It's like driving a high-performance sports car with a tank full of the cheapest grade of gasoline.
The Radia R-800s also exhibited a unique characteristic I've not encountered before: When playing music, especially vocals, they retained a strong sense of clarity and detail, even when I was listening from an adjacent room.
The Radia R-800s are the first in-wall speakers I have auditioned that do not need a subwoofer, although BG offers an in-wall subwoofer, the Radia R-88, with two 8-inch woofers. Without a subwoofer, bass response was tight and extended in every music disc and movie soundtrack I played. The bass track in James Taylor's "Line 'Em Up," (Hourglass SACD, Sony Music) sounded authoritative, well defined, and solid, as did "Why Can't It Wait Till Morning" from The Best of Fourplay (Warner Brothers Records). The separate amplifier, the BGA-2500, that drives the two long-throw 8-inch woofers in each speaker employs BG's BASH technology, using a switching power supply and a discrete analog output stage for high efficiency and very cool operation. (The BGA-2500 is available with or without rack-mount ears.) Since the midrange planar driver's crossover is set at 250 hertz, you can drive the rest of the system with an amplifier or receiver, and BG recommends power output of 100 to 250 watts per channel to adequately handle musical peaks. The Radia R-800s have a rated sensitivity of 93 decibels and are capable of a claimed maximum SPL output of 120 dB. I don't think I achieved that level, but, even at high levels, the Radia R-800s retain their high degree of clarity and detail.
I only enjoy watching movies with a good sound system, and, in my opinion, the quality of the sound is more critical than that of the picture. I'm in the process of acquiring an LCD flat panel, and, in the meantime, I'm using a 19-inch CRT TV. Although listening to 7-foot-tall speakers and watching a small TV was a sensory disconnect, the Radia R-800s more than compensated for the small picture size. With the Radia R-800 speakers, it seemed as if I were seated in a widescreen cinema when watching the March of the Penguins and Crash DVDs, two very different but equally compelling films with full, enveloping soundtracks. My 19-inch screen suddenly seemed like it was 19 feet.
The Radia R-800 speakers present a very wide, tall, deep, three-dimensional soundstage with pinpoint imaging. The soundstage makes the musical presentation sound large, enhancing the feeling that you're listening to a live performance. The wide sweet spot is also ideal for large rooms and off-axis listening where everyone may not have the best seat.
Construction Quality
The construction quality of the Radia R-800s is excellent, with a steel frame complemented by a finely machined aluminum baffle. Each speaker secures to the wall with 12 dogleg clamps, six on each side, and the grille slides into a channel along the sides of the frame for a clean appearance.
The Radia R-800s are suitable for new construction or retrofit installations. BG strongly recommends cavity bracing with construction adhesive and/or building dedicated back boxes or enclosures for the speakers, and I agree. The woofers are capable of moving lots of air, and, unless the cabinet or wall cavity is very solid and well sealed, vibrations and resonance are inevitable. I used an entire tube of caulking with drywall screws spaced every 6 inches on each speaker with good results but still had a few rattles. If I were to install them permanently, I would build back boxes, brace the walls, and seal every joint. Make sure your installer does the same. The benefits will become evident in solid bass reproduction.
In Summary
The BG Radia R-800 speakers are a giant step forward in architectural loudspeakers. Priced at $12,000 per pair (including the external amplifier) they are ideal for installation in a dedicated media room. The Radia R-800s aren't for everyone, but, fortunately, BG has introduced a line of five new Radia in-walls that use the same drivers and design principles with similar sound qualities and more affordable pricing. The new, smaller models are also certain to please those who must convince a wary spouse. But, if you have a large room or theater and want outstanding audio performance, don't overlook the Radia R-800s. Describing the sound quality of the BG Radia R-800s with words doesn't match the experience of hearing them. I can only imagine what a multichannel system with five Radia R-800s would sound like—now that would be extreme listening.
Highlights
• Full-range in-wall speakers with planar-ribbon midranges and tweeters in a vertical-line array
• Excellent detail and definition
• Clean and open-sounding midrange performance
• Solid, well-defined bass response
At A Glance: BG Radia R-800 In-wall Speakers
Features
Number of Channels: 2
Power Rating (watts per channel): 500
Frequency Response: 20 Hz–20kHz
Dimensions (H x W x D, inches): 3.95 x 16.9 x 14.7
Weight (pounds): 17.5
Price: Included with speaker pair
Connections
Inputs: Line-level RCA (2)
Outputs: Line-level RCA (2), high-level speaker
outputs with five-way binding posts (2 pair)
Speaker: Radia R-800
Type: Three-way in-wall
Tweeter (size in inches, type): 3 x 2.5, Neo3PDR planar-ribbon panels (16)
Midrange (size in inches, type): 10 x 5, Neo10 planar-ribbon panels (6)
Woofer (size in inches, type): 8, long throw (2)
Nominal Impedance (ohms): 4
Recommended Amp Power (watts): 100
Available Finishes: White
Dimensions (H x W x D, inches): 81.5 x 11.58 x 3.7
Weight (pounds): 68
Price: $12,000 per pair including BGA-2500 amplifier
Ratings: BG Radia R-800 In-Wall Speakers
Build Quality: 96
Well built with a steel frame and machined aluminum baffle
Value: 96
One of the most expensive in-walls, but well worth it for a no-holds-barred media room/home theater
Features: 95
Separate bass amp reduces demand on main amp or receiver
Performance: 98
Excellent transparency, detail, and definition, especially with vocals
Ergonomics: 93
This is not a speaker for the do-it-yourselfer. Have them professionally installed with extra wall and cavity bracing
Overall Rating: 96
These huge BG in-walls employ planar-ribbon drivers to remarkably transparent ends. They can be both subtle and powerful.
General Information
Radia R-800 In-Wall Speakers, $12,000/pair
BG Corp.
(775) 884-1900
www.bgcorp.com
Company
Bohlender-Graebener Corporation, now known as BG Corp., is a Nevada-based company that since 1994 has produced a broad range of loudspeakers, all of them featuring BG's proprietary ribbon-tweeter technology. In addition to a line of conventional speaker pairs—the flagship of which, the Radia 520i ($4000/pair), Larry Greenhill reviewed in December 2004—BG manufactures a wide range of in-wall, on-wall, and custom-installation speakers. The Z1 ($499/pair), the first model in BG's affordable Z series, is a fairly unassuming shielded bookshelf speaker in which BG's ribbon tweeter is coupled with a 5.25" aluminum-cone woofer.
BG feels strongly that a ribbon driver is the best way to reproduce midrange and high frequencies. The mass of BG's tweeter diaphragm is 30–50 times less than that of a typical dome tweeter. Thus, according to BG, the tweeter's mass is comparable to that of the air that is vibrating along with the diaphragm. It can be energized more quickly, stores much less energy and inertia, can stop vibrating sooner, and its decay pattern is cleaner.
BG credits two major developments in materials science over the last two decades that have enabled further advancement in ribbon technology. First, neodymium has become less costly, making it viable for use in the motor structure of ribbon tweeters. Magnets made of neodymium have magnetic energy 20–30 times greater than the ceramic magnets used in the ribbons of the 1970s and '80s. Second, BG makes their diaphragms of Teonex film, developed by DuPont in the 1990s. BG feels that Teonex can withstand higher temperatures and is stronger than the Mylar film used in earlier ribbon designs.
BG set out to design a ribbon tweeter with smooth frequency response, low noise, wide horizontal dispersion, and high efficiency, all at low cost. Their patented ribbon design uses fewer magnets than conventional ribbons by eliminating side magnets positioned close to the clamping frame and, instead, placing strips of acoustically semitransparent absorptive material close to the diaphragm in the area between the diaphragm and the metal plates. BG says this allows them to largely retain the transducer's necessary sensitivity while providing sufficiently wide horizontal dispersion.
Sound
I placed the Z1s on my trusty Celestion Si stands, loaded with sand and lead shot. Although BG felt there would be a slight improvement in sound on-axis with the speakers' grilles removed, I got the most timbrally natural sound with them left on, which is how I did most of my listening. The difference was slight, however.
The Z1's detailed, delicate, coloration-free, and holographic midrange presentation impressed me with all vocal recordings. The notes I took while listening to the acappella introduction of Brian Wilson's "Our Prayer," from SMiLE (CD, Nonesuch 79863-2), read the same as my notes for Madeleine Peyroux's "Hey, Sweet Man," from Dreamland (CD, Atlantic 82946-2): "gorgeous, silky, holographic vocals." The Peyroux track also had me fixated on Marc Ribot's dobro; the extended and detailed high-frequency capabilities of the Z1's ribbon tweeter revealed levels of detail, delicacy, and immediacy that I'm not used to hearing from a $499/pair speaker.
The Z1's resolution of the high frequencies of vocal sibilants was so accurate that I felt I was listening to Janis Ian's Breaking Silence (CD, Analogue Productions CAPP 027) for the first time—a tough thing to do, considering that it's the most-played recording I own. The Z1's combination of low-level dynamic articulation and what appears to be a remarkable tweeter let me hear tactile nuances from this recording that I'd not noticed before through any speaker costing less than $2000/pair.
I began to mine my collection for recordings of acoustic stringed instruments. Don Fiorino's lotar—a fretless, four-string Moroccan lute—on Attention Screen's La Tessitura (CD, Hojo HOJO 10) sounded as if it was in the room with me. My listening notes: "Texture! Timbre! Transients!"
The Z1's low-level dynamic capabilities made me want to listen to woodwinds and brass as well as strings. On his Way Out West (CD, JVC VICJ 60083), Sonny Rollins' tenor sax was incredibly realistic in timbre, texture, and dynamics. Similarly, the saxes and trombones on the Jerome Harris Quintet's recording of Duke Ellington's "The Mooche," from Editor's Choice (CD, Stereophile STPH016-2), bloomed with a sense of organic and linear dynamics, with no trace of compression. The ride cymbals during the horn solos also seemed very lifelike.
The Z1 was also able to articulate transients with senses of speed, delicacy, and attack that I've come to associate only with much more expensive speakers. The transient attacks, decays, and timbre of Gary Burton's vibes on his first album, New Vibe Man in Town (LP, RCA LSP-2920), were sufficiently lifelike that I dropped my notebook. My mouth was agape as I focused on Burton, then an 18-year-old wonder trained in the classical marimba, trading fours with Joe Morello's brushes on "Joy Spring."
One acid test I use to test a speaker's high-frequency articulation is "Tiden Bar Gor," from Depth of Image (CD, Opus3 CD 7900). The beginning of the track features the interplay of two acoustic guitars, one steel-string, one nylon-string. With speakers of exceptional HF resolution, it's pretty obvious which guitar is which; through many affordable speakers, they can sound quite similar. With the BG Z1, the difference between the two guitars' textures was as easy to delineate as it is with my $12,000/pair Nola Circes.
One aspect of the Z1's HF performance concerned me, though only with certain recordings. If I played music with significant high-frequency energy and fast transients, such as the more pyrotechnic piano solos on the Jamie Saft Trio's Astaroth (CD, Tzadik TX 7348), the highs seemed to have an "etched" quality, particularly when the speakers were driven hard. But this, the Z1's sole deviation from neutrality, reared its head only occasionally.
The Z1's midbass and upper-bass performance was quite natural. A slight bit of warmth in the midbass was evenly distributed across a broad frequency range and did not detract from the musical experience. Ray Brown's bass solos on Way Out West were warm but natural, it was very easy to follow the pitches, and there was no sense of sluggishness or overhang.
Although the Z1 never sounded bass-shy, it didn't seem to have much in the way of low-bass extension. The bass drums on Antal Dorati and the London Symphony's recording of Stravinsky's The Firebird (CD, Mercury Living Presence/Classic SR 90226) and the CD layer of David Chesky's Area 31 (SACD, Chesky SACD282) sounded natural but did not shake the room much, and the lower register of the organ pedals on John Rutter's Requiem (CD, Reference RR-57CD) were missing in action.
To achieve a well-balanced midbass presentation that didn't sound bass-shy, I had to follow JA's setup recommendations. Normally, I place bookshelf speakers on stands anywhere from 2' to 4' from the front wall, depending on the speaker. To achieve a natural bass balance with the Z1s, I had to place them 1' from the front wall, which affected their soundstage presentation. On any well-recorded acoustic music, the speakers "disappeared," placing pinpoint holographic images across the soundstage. However, when the Z1s were only 1' from the front wall the depth become somewhat foreshortened. At 2' from the wall the soundstage depth increased significantly, but then the speakers sounded a bit bass-shy. This effect was sufficiently noticeable that I preferred the sound of the Z1s closer to the wall rather than out in the room.
For a bookshelf model with limited low-bass extension, the BG Z1 performed admirably as a rock speaker, and at fairly high volume levels. Wandering down memory lane, I cranked up "Jingo," from Best of Santana (CD, Columbia CK 65561), one of my favorite tunes from the set list of my old high school band, and started twitching around the room in my T-shirt and shorts, playing a mean air B-3. (My wife and kids weren't home. The dog looked at me strangely and left the room.) I had a similar reaction to the dramatic power and authority of Kraftwerk's Minimum-Maximum at 95dB (CD, EMI ASW 60611).
In fact, almost all the recordings I threw at the Z1 sounded natural and involving. Bill Frisell's idiosyncratic arrangement of "I Heard It Through the Grapevine," on East/West (CD, Nonesuch 79863-2), was devoid of coloration. This live recording sounded so immediate that I felt I was sitting in Yoshi's club in Oakland listening to the band.
Comparisons
I compared the BG Z1 ($499/pair) to the NHT SB-3 ($600/pair), the Nola Mini ($695/pair), and the Epos M5 ($650/pair).
The NHT SB3's rich midrange was similar to the BG's, but with much less detail in the midrange and highs. The NHT's bass extension and high-level dynamics were more impressive than the BG's, however. The Epos M5 revealed more midrange detail than the BG Z1, and had a tighter, slightly less warm midbass. The M5's highs were also rather extended, but the Z1 was a bit more detailed. The Nola Mini had better resolution of midrange detail than the BG Z1, and even better articulation of low-level dynamics. The Mini's highs were as extended as the Z1's, but the BG's highs seemed a bit more delicate. The Nola Mini's bass extension and high-level dynamics were superior, however.
Summing up
Overall, the BG Z1 was a top performer on a wide range of music—it played a lot of music for its price. The Z1's ribbon tweeter is a detailed and colorless transducer as long as it's not pushed too hard with complex material, and appeared to integrate seamlessly with the speaker's dynamic woofer over a broad range of program material. You may have to experiment with speaker placement, however, to achieve your optimal blend of bass extension and soundstage depth.
I congratulate BG Corp. on producing a cost-effective loudspeaker for audiophiles on a budget who nonetheless seek something a bit more innovative than "two dynamic drivers in a bookshelf box." Excellent work!
Certain loudspeaker manufacturers are known for "signature" speaker technologies, such as Klipsch for its horn drivers or MartinLogan for its curved electrostatic arrays, and Bohlender-Graebener is best known for using planar magnetic or "ribbon type" drivers. Based on the few, too-brief listening experiences I've had with them, Bohlender- Graebener's full-size planar magnetic speakers struck me as promising and impressive performers, but whose pricing put them beyond reach of some listeners. Happily, though, Bohlender-Graebener offers a great option for budget-minded enthusiasts: the affordable Radia Z-series—speakers that use hybrid combinations of traditional, piston-type bass/midrange drivers and ribbon tweeters. Does the hybrid approach work? There is certainly good reason to think so, judging by the comments made by my colleague Neil Gader in his recent review of the Radia Z7 tower-type speaker for our sister magazine, The Absolute Sound. In fact, Neil found the sound of the Radia Zs sufficiently interesting that he suggested I review them for AVguide Monthly, this time evaluating the Z7s as part of the complete Radia Z-series 5.1-channel surround system. And so the idea for this review was born.
The Radia Z surround system comprises the tall, slender Z7 tower type speakers as reviewed in TAS, plus a companion Z5 center-channel speaker, a pair of small Z1 monitors used as surround speakers, and a matching Z Sub subwoofer with built-in 150-watt amplifier. All models in this lineup (save for the subwoofer) feature Bohlender-Graebener's 5 ¼" aluminum-coned mid-bass drivers, proprietary Neo3PDR (Progressive Drive and Radiation) ribbon-type tweeters, and Linkwitz-Riley crossover networks (which allow steep crossover slopes, yet keep drive units in phase with one another through the critical crossover region). This shared driver and crossover technology made for desirable consistency in voicing among all the Radia Z speakers—a factor that really helped this speaker system create smooth, well balanced surroundsound fields during my listening tests. The Radias are supplied with attractive press-on grill frames, but to enjoy all the clarity and openness of which these speakers are capable, you willwant to remove those frames and set them aside. My review samples were covered on all sides (rear panels included) in a gorgeous cherry veneer that received a strong "thumbs up" cosmetic approval rating from my wife and kids.
There's no denying that the Radias are lovely to look at, but are they as easy on our ears? In many respects they are. In the interest of clarity, let me comment first on the semi-full-range Z7 tower speakers, and then on the complete Radia surround system.
Before I first heard the Z7s, I wondered if BG's exotic ribbon tweeters and metal-coned bass/midrange drivers would draw undue attention to themselves, but it took only a few minutes of listening to recognize that the opposite was more nearly the case. Why? First, because the Radias' aluminum bass/midrange drivers sounded notably warm, rich, and smooth-not in any way edgy or metallic (dispelling the goofy high-end audio/home-theater myth that holds that metal drivers produce characteristically metallic sounds). Second, the Radias' signature Neo3PDR ribbon tweeters offered articulate, smooth, and extended treble response, with excellent speed and definition on sharp transients, yet without so much as a hint of aggressiveness or excess brightness (this is a fine tweeter, and one that clearly demonstrates the strengths of ribbon technology). Putting these factors together, the Z7s proved to be, exactly as Neil Gader observed in his TAS review, easy to listen to and offering warm and plentiful (though not particularly tightly defined) mid-bass, a smooth and gently recessed midrange, and classy, well-focused highs.
I found the Z7s did have some shortcomings, particularly in the areas of soundstaging and overall textural continuity—areas where my impressions of the Z7's performance varied somewhat from Neil's. While the Z7s are fully capable of resolving the kinds of subtle spatial cues and details that ordinarily make for good soundstaging, I found their soundstaging decent but not exceptional (falling short of the potential I think the terrific BG ribbon tweeter holds). The problem was that the sound, though clear and finely textured, somehow tended to "cling" to the faces of the Z7s rather than breaking free to produce compelling three-dimensional soundstages. Perhaps this problem was related to the issue of overall top-to-bottom textural continuity. My observation was that BG's aluminum-coned bass/midrange driver and its ribbon tweeter, though each a very good driver in its own right, did not speak with a single, unified voice. Instead, the ribbon tweeter sounded just enough "faster" and more finely resolved than the aluminum bass/midrange driver for there to be some audible discontinuity in the crossover region between the two. In fairness, I should point out that the only reason this issue even comes up is because BG provides us with a ribbon tweeter whose performance stands head and shoulders above that of the high-frequency drive units you'd normally find in speakers in this price range.
Even with these minor drawbacks (and they are minor), I do concur with Neil Gader's generally favorable assessment of the Z7.
The game becomes much more interesting, however, once you step up from a stereo pair of Z7s to the full Radia Z surround system, as several performance factors start working in your favor in a big way. First, you suddenly have 5.1 (rather than just two) similarly voiced Radia Z speakers jointly sharing responsibilities for presenting three-dimensional soundstage information. I found this change alone carried unexpectedly big benefits, greatly improving the Radia Zs' ability to create believable three-dimensional soundstages. The improvement was quite clear cut on recordings such as the beautiful "Canon" track from Béla Fleck and Edgar Meyers' Music for Two [Sony Classical]. This live recording captures a haunting duet in the form of an intricate round (think "Row, Row, Row Your Boat" on steroids) between Meyers' acoustic bass and Fleck's banjo. As heard through the Z7s alone, this recording sounded a little flat or two-dimensional; but the full Radia Z surround system created a much more believable illusion of a real banjo and bass playing in a real hall, and in the presence of a real audience. Once you distribute the imaging workload across five voice-matched Z-series speakers and a good powered subwoofer, imaging weaknesses are minimized, and the Radias' inherent smoothness and clarity can assert themselves, significantly improving three-dimensionality.
But the Radia Z surround system also shows improvements in other important areas—particularly in terms of overall textural continuity (or top-to bottom evenness of voicing). Both Neil Gader and I noted that the Z7s showed a slightly recessed midrange sound; but through the full Radia Z surround system, that slightly recessed quality largely went away, and the surround system's midrange sound seemed smoother, too. I noticed these improvements, in particular, on recordings that highlighted (and clearly exposed) the sound of female voices, such as the "Por Causa de Você" track from Rosa Passos and Ron Carter's beautifully recorded Entre Amigos [Chesky]. Passos' voice has a quality that is at once dusky and full-bodied, yet also delicate and ethereal, and the Radia Z surround system did a beautiful job of capturing those elusive qualities with a wonderful touch of human warmth.
Compared to the sound of the Z7s, then, the Radia surround system's midrange voicing sounded more fully fleshed-out and better balanced with respect to the system's warm, rich mid-bass. Bass quality in the surround system was also improved, thanks to the Z Sub powered subwoofer. While the Z Sub is neither the last word in bass articulation nor definition, it sounds more powerful than its power rating would suggest, and it significantly extends the low-frequency reach of the system with bass voicing that is consistent with, and better controlled than, that of the Radia Z main, center, and surround speakers. On music or film soundtracks where the Z7s' bass could sound a little "woolly" and overblown—for example, on the cannon fire in Master and Commander— The Far Side of the World [20th Century/Fox]—the Z Sub added a welcome measure of bass power, extension, and control. Thus, on Master and Commander, the Z Sub enabled me to hear the initial crack and then thunderous low-frequency roar as the sound of the cannon fire carried over the water, and then—a split second later—the shuddering shockwaves of cannonballs sizzling through the air, just over my head.
Finally, the full Radia Z surround system seemed to mitigate, though not completely eliminate, problems of textural discontinuity between the Radia tweeter and bass/midrange driver. Perhaps this improvement resulted from the simple fact that, in a 5.1-channel surround system, there are more speakers to share the workload, meaning that individual speakers do not need to play as loudly as they would in a stereo system to achieve a desired volume level. With the volume levels of individual speakers in the systems reduced, textural discontinuities became less noticeable, even as the Radia Z's natural smoothness and clarity came shining through. This improvement made a worthwhile difference on richly detailed recordings, such as jazz guitarist Tuck Andress' stunning solo album Reckless Precision [Windham Hill]—a recording where textural subtlety means everything, and where the Radia surround system's better-integrated voicing helped create, and then maintain, the illusion that a master jazz guitarist had come to play a private concert in my living room.
To synopsize, let me say that the Bohlender-Graebener's Radia Z surround system preserves everything that is good and right about the Z7 floorstanding speaker, while offering meaningful improvements in several important areas. You'll still enjoy the mid-bass warmth, midrange smoothness, and treble clarity of the Z7, but now with greater three-dimensionality, better midrange balance, tighter and more extended bass, and somewhat more comfortable integration between BG's superb ribbon tweeter and its aluminum bass/midrange driver. Importantly, the Radia Z surround system is easy to drive, not at all fussy about associated electronics, and capable of performing equally well on films and music (a claim not all surround speaker systems can make).
This system's sound won't appeal to everyone, nor will it provide quite the sort of top-to-bottom focus and lucidity you might hear from the larger (but much more expensive) Bohlender-Graebener planar magnetic designs. But for those who have grown weary of speakers that deliver icy, etched, and aggressive sound in the name of definition and detail, the Radia Z system offers an oasis of sonic warmth, smoothness, and relaxation. At a total of just under $2350, it also very competitively priced. As always, we strongly urge you to hear the Radia Z system for yourself, so that you can determine whether its distinctive magic works for you.
Specifications
Manufacturer's Suggested Retail
Price: Radia Z7 mains, $999/pair;
Radia Z5 center channel, $399/each;
Radia Z1 surrounds, $499/pair; Radia
Z Sub, $599/each; Total Radia Z 5.1-
channel system price: $2,496
Type; Mains: Floorstanding, 2-way, 3-driver, bass reflex (40" x 8.75 " x 10.25", 42 lbs.)
Center channel: tabletop, 2-way, 3- driver, bass reflex (10.7" x 6.8" x 9.5", 22 lbs.)
Surrounds: Powered subwoofer: Floorstanding (18.1" x 12.6" x 16.54", 56 lbs.)
Driver Complement L/R: (2) 5 ¼ '' aluminum bass/midrange drivers; (1) Neo3PDR ribbon tweeterDriver
Complement Center: (2) 5 ¼ '' aluminum bass/midrange drivers; (1) Neo3PDR ribbon tweeterDriver
Complement Surrounds: (1) 5 ¼ '' aluminum bass/midrange driver; (1) Neo3PDR ribbon tweeterDriver
Complement Subwoofer:(1) 10" Paper composite cone woofer with 3" voice coil and high excursion rubber surround
Integral Amplifier Power for Subwoofer: 150 watts
Subwoofer Operating Principle: Bass Reflex
Sensitivity L/R 89dB
Sensitivity Center 89dB
Sensitivity Surrounds 88dB
Impedance L/R 4 ohms
Impedance Center 4 ohms
Impedance Surrounds 8 ohms
Manufacturer Information
Bohlender-Graebener
1780 Forrest Way
Carson City, Nevada 89706
(888) 875-2627
www.bgcorp.com
Associated Equipment
Sony STR-DA-9000ES AVR; Sharp SD-HX500 1-Bit Digital AVR/universal player; Integra DPC-8.5 universal player; Pioneer PDP-505 HD plasma display; Chang Lightspeed CLS-HT 1000 Mk II power-line filter; Synergistic Research X2 interconnect, subwoofer, and speaker cables (featuring proprietary Synergistic active shielding system). Equipment Review
© Copyright 2004, Absolute Multimedia
Chris Martens
AVguide Monthly
www.avguide.com
