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Positive Feedback ISSUE47
as reviewed by Arnis Balgalvis
I was smitten with the Salon2 loudspeaker from the moment I first saw a picture of it. Oh, yes! The tall proportions, the lines, the curves, the drivers, it sure was a thing of beauty. But what jumped out at me in particular was the sculpted front panel area where the tweeter and the mid-range drivers were mounted. If Revel is going to such lengths to address the diffraction aspects, I thought, a lot more has to be going on in other areas that contribute to excellence in loudspeaker performance.
Why this leap of faith? Well, Revel has managed to become, in a very short time, one of the prominent players in the loudspeaker arena. Led by Kevin Voecks, Manager of Product Development for Harman High Performance A/V, they launched their initial Ultima series of speakers for the two-channel and home theater venues only some 12 years ago. It did not take long for them to establish a solid reputation in the realm of high performance loudspeakers.
There is one very important reason why Revel got a jump on the rest of the industry. They have a Big Daddy, Harman International. Knowing that a serious commitment is the first requirement for getting serious results, Harman went and outfitted Revel with the best resources and R&D facilities that money can buy.
First off, there's Kevin Voecks, a no-nonsense person if there ever was one. Kevin has no time for hype, folklore, or other non-scientific babble. This means that the product-related activities at Revel have to be based on solid fundamentals of acoustics as well as electrical and mechanical engineering. Everything starts out as a text-book design followed by an involved R&D process where the product is brought to fruition.
Second, Kevin has assembled an eclectic staff of researchers, acousticians, electrical and mechanical engineers to perform the extensive engineering that is always the backbone of any successful product.
And third, Harman International provided Revel with arguably the finest R&D facilities in the industry. They consist of such exceptionally robust resources as Computer Aided Design (CAD), Finite Element Analysis (FEA), Laser Interferometer analysis, Stereo Lithography Apparatus and elaborate Anechoic Chamber facilities.
But Revel can boast of having something truly unique in the industry: the Multichannel Listening Lab (MLL).
In the MLL trained listener panels can compare designs, be they evolving or final, under true "double-blind" conditions. Listening to a wide variety of familial music, they evaluate speakers in a setting that can be varied to simulate environments of residential conditions and room sizes. The MLL contains a computer controlled platform that is part of a pneumatic conveyor system which is capable to reposition speakers and then place them, in a matter of seconds, in the same exact location even if different models are involved. All this is done behind an acoustically transparent curtain hiding the identity of the product under test.
Revel puts to practice these advanced listening techniques to "correlate between objective laboratory measurements like those recorded in an anechoic chamber and ‘in-room' sonic performance like the average listener might experience at home".
Revel also has an additional advantage in terms of scale; almost all their drivers are used in broad across-the-board applications with regard to all the products in the Ultima2 series loudspeakers.
Kevin explained that that is not their specific objective in all cases even though the same transducer ends up being suitable for more than one model as in the case of the 4-inch midrange which is used in the Salon2, Studio2, Voice2 and Gem2. But, in the typical meticulous Revel manner, the 8-inch woofers in the Salon2, Voice2 and Gem2 are actually optimized for each of those specific applications.
The Product Proper
The Salon2 loudspeaker is a four-way design, using a six driver array consisting of one 1-inch tweeter, one 4-inch midrange, one 6 ½-inch mid-woofer, and three 8 inch bass-reflex loaded low frequency drivers.
The speaker stands 53.25 in high, is 14 in wide and 23 in deep. The shipping weight is specified at 178 pounds.
By deliberately choosing to go with several smaller cone woofers and stacking them up vertically, Revel is able to achieve a narrow cabinet profile which is instrumental in managing diffraction artifacts. This approach has the advantage that at the low frequencies the three 8-inch woofers, working in unison, can displace as much air as a single 14-inch woofer cone. Having three woofers per speaker also has the noteworthy benefit of greatly reducing voice coil heating in each driver, which essentially eliminates compression. This is an important aspect that goes a long way to preserving dynamics and "punch," even at elevated listening levels.
Revel claims that the trim cabinet contributes to the speaker's ability to present a finely focused image and aids in originating a soundstage as wide as called for by the recording.
Each of the drivers in the Ultima2 series has been designed from the ground up relying on Computer Aided Design, Finite Element and Laser Interferometer analysis.
The 1-inch tweeter utilizes beryllium for the dome and incorporates a wave guide to achieve dispersion characteristics that match those of the mid-range driver. This new tweeter now boasts a significantly higher output capability and lower dynamic compression than their previous design.
When choosing the material for the tweeter dome, Revel considered three key constants: velocity of sound, density of the material and Poisson's Ratio as an indicator of material elasticity appropriate for audio.
Even though the velocity of sound of beryllium is somewhat lower than Chemical Vapor Deposited Diamond (13000 vs.16200 m/s), its density, and therefore weight, is only 50% of the CVD Diamond. However, when Poisson's Ratio for each material is taken into account, with beryllium being 0.08 while CVD Diamond is 0.31, beryllium becomes the obvious choice. As a result, the Ultima2 beryllium tweeter has the capacity to perform over the more than 4 octave range of 2kHz to well beyond 50kHz as a true piston while holding dynamic compression and distortion to very low levels.
An additional challenge for the tweeter was the dispersion of the upper frequencies. Yes, physics dictates that the tweeter needs to be small if it is to respond very nimbly when dealing with very high frequencies while the midrange driver is significantly larger to handle frequencies that are lower.
But the main reason that the tweeter must be small is for good dispersion at higher frequencies. If a diaphragm is large relative to the wavelengths it is reproducing, it will have too narrow a dispersion pattern, and will thus deliver less high frequency energy to the listening environment. Revel has demonstrated that off-axis response is as important as on-axis, since the off-axis response contributes significantly to the "sound power," or total radiated output of a loudspeaker.
In the case of the Salon2 the corresponding tweeter and mid-range dimensions are 1 and 4 inches.
Revel solved the dispersion problem by implementing a wave-guide for the tweeter. By crafting a wave-guide that has the required conical section in conjunction with specific geometrical details at its entrance and exit, they achieved the desired directivity characteristics to match those of the mid-range driver in the cross-over region. The boost in gain due to the wave-guide allowed the tweeter's cross-over point to be lowered, resulting in an increased power handling capacity and significantly decreased compression. In addition, this tweeter exhibits a significantly wider dispersion pattern covering the region above 9kHz.
In the ideal world loudspeaker drivers should not exhibit distortion-creating breakup modes. For these diaphragms, behavior as true pistons well before and also well beyond the specific range of the desired operating spectrum is an absolute must.
The quest for true pistonic behavior leads to specialized configurations and materials —in the Ultima2 case, beryllium and titanium—which will not yield to deformation despite encountering tumultuous driving forces that are generated during the playback process.
The midrange, mid-woofer and woofer transducers for the Salon2 have been fitted with inverted-dome titanium diaphragms. Titanium exhibits excellent tensile-strength characteristics that, in combination with the inverted-dome geometry, result in very high-frequency break-up modes. This is achieved not only over the required operating regions but well beyond them as well.
To aid in achieving clean high output along with low dynamic compression, these drivers have oversized voice-coils wound with flat copper "ribbon" wire. The transducers are able to maintain pistonic behavior even when operating at very high sound pressure levels.
The list continues with the refined dual neodymium magnet motor configuration, along with the aluminum flux stabilization ring, all to reduce the audible effects of second and third order harmonic distortions.
Looking at the cross-over points of 150Hz, 575Hz, and 2.3kHz we see that the frequency band is divvied up in a manner where each driver is not asked to cover too much of the assigned spectrum. The cross-over slopes have been chosen to provide 24 dB/octave roll-off characteristics and are very close to textbook Linkwitz-Riley 4th-order acoustic filters. Kevin Voecks explained: "All of our Corporate research, which I have also challenged and tested, proves the sonic superiority of high-order filters. It's a cornerstone of our designs." And when I brought up the subject of phase and time alignment, Kevin responded: "Phase is a complex (no pun intended) issue. There was a time when I made 1st-order filters and "time-aligned" transducers for "phase accuracy." Stanley Lipshitz made me see the error in my ways via listening tests, and I have never looked back."
The cross-over was designed using CAD software, sophisticated measurements and controlled listening tests in the Multichannel Listening Lab.
The topography was then implemented with high quality capacitors, air-core inductors, and point-to-point wiring. Ultra-high-purity copper conductors form the connections from the cross-over to each of the transducers.
The whole Ultima2 series of speakers uses discrete filter boards for each specific frequency spectrum. Each filter board has been located strategically within the enclosure to avoid magnetic and physical interference.
Every visitor to my listening room, as soon as they saw the Salon2s, had complimentary comments about their appearance. Not only is it expertly executed to give the speaker a stunningly elegant presence, it is also an integral part of the overall design intended to raise the level of performance that the Salon2 delivers.
The prominent portion of the enclosure forming the sides and the rear in one sweep is actually a single piece of MDF material. That is surprise number one. Surprise number two is that this substantial curved segment is a 9-ply laminate! In addition, to further enhance the rigidity of the speaker enclosure, significant reinforcement is provided by a number of sizeable internal braces. This sophisticated configuration of the enclosure has been devised to withstand the emphatic pressures of the internal waves that the 3 woofer drivers produce so that the cabinet maintains a high degree of rigidity and, consequently, keep colorations to a minimum.
The 2 ½ inch thick front baffle, also MDF, has been sculpted to address diffraction effects. By providing complex-radius edge detailing where the mid-range and tweeter are mounted, diffraction artifacts have been kept to an absolute minimum. As a result, gains in better dispersion and a smoother response were attained.
Connections for the speaker cable are made on a panel at the lower rear portion of the loudspeaker. Two sets of binding posts are provided to accommodate bi-wiring. This panel can be hidden from view with a plastic door that has been sculpted to follow the curvature of the rear of the cabinet.
Also provided on this panel are two switches. A 5 position "Tweeter Level" adjustment permits the tweeter output to be changed over a +/- 1dB range in 0.5 dB steps while the other switch, labeled "Low Frequency Compensation" allows the user to choose a change in the woofer response among three settings: Normal, Contour, or Boundary. "Contour" simplifies placement in rooms with especially troublesome room-mode problems, "Boundary" position compensates for a position where the speaker ends up too close to a wall, or takes into account a placement in a confined area where the speaker might be hidden in home theater applications.
The Equipment, Source Material, and Placement
I usually prefer to hear a loudspeaker in at least two different venues to allow me to get a more thorough idea of what the product is all about. In the case of the Salon2 this was not possible to arrange.
I did the next best thing and listened to the speakers placed in two completely different locations in my listening room. No, I did not just move them a few inches in the same basic area. Instead, I relocated them in my "L" shaped listening room by using each of the two "legs" of the "L" configuration. This allowed me to set the speakers up where they could be a) spread apart quite significantly with loads of space behind them, or b) where they were closer together with less space behind them. Also, in the first version, I had only a couple of feet of space behind the listening position, while in the second case there was more room behind the listener.
I am also for evaluating a speaker, or, for that matter, any product, with as many differing components in the system as possible. A speaker, in my book, should be driven with at least two different power amplifiers to see how it reacts to this kind of change.
I happened to have a very eclectic selection of equipment available so the Sallon2s got quite a work-out. I used 3 digital signal sources (Nova Physics Memory Player, the Perfect Wave Transport, and a "home brew" Music Server—the same configuration that the folks at Reference Recordings suggest as described on their site), 3 DACs (Perfect Wave DAC, MSB Technologies DAC III with the Signature Volume Control, the Signature 32X Digital Filter, the Signature DAC Modules and the Signature Input Oversampling Board, and also the Berkeley Audio Design Associates Alpha-DAC), 2 monoblock power amplifiers (Bryston 28B-SST and the Marantz MA-9S2). To complete my connections, I used the Tara Labs "Zero" Gold balanced interconnects and the Tara Labs "Omega" speaker cables, two components that are, by far, the most detailed, open and neutral cables in my experience.
The Source Material
Though all source material used was digital, it was not exactly just your run-of-the-mill Red Book kind. Since the Nova Physics Memory Player delivers significantly refined 44.1/16 WAV files and the PS Audio Perfect Wave Transport also goes above and beyond in presenting better handled digital data, the Salon2s were evaluated with above-average quality signal sources.
But there's more. Using my computer as a music server and also the Perfect Wave Transport I unleashed digital material at significantly higher resolution than 44.1/16.
The hard disc of the Music Server held a number of 176.4/24 files available on the Reference Recordings' HRx discs. The HRx is Reference Recordings (www.referencerecordings.com) trade name for their DVD-R discs that contain 176.4/24 bit WAV files, material that is a direct bit by bit replica of the Keith Johnson master recordings that he does for Reference Recordings. My music server also contains 192/24 files that David Chesky of Chesky Records (www.chesky.com) has produced.
In addition, I also used a couple of 176.4/24 DVD-ROM discs that Todd Garfinkle of MA Recordings (www.marecordings.com) provided.
These recordings high-resolution recordings are a revelation of how well music can be recorded and then be available for a demonstration of taking musical enjoyment to an absolutely new level.
The Perfect Wave Transport is a component of outstanding merit. It stands out with its capability of being able to directly play DVD-R discs with WAV files, and therefore the HRx discs and also the MA discs, without having to rip them to a hard disc of a Music Server. Just pop the disc into the drawer and away you go. To my knowledge, the only other component with a DVD-R WAV file playback capability is the Boulder 1021 Disc Player but that is a significantly more expensive device than the $3000 Perfect Wave Transport.
I find it particularly exciting that material of this resolution is becoming commonly available today. It has clearly become a distinct category of source material free of tinges of exclusivity. Chesky's HDtracks.com is a very comprehensive source for high resolution downloads with a number of other companies such as MA Recordings, Naim, and Linn making high-rez material available.
These developments raise the quality of the source material to completely new level of refinement and allow components to be subjected to resolution levels of unprecedented sophistication. As a result of the extensive developments in the computer audio high-rez area, the musical enjoyment possibilities are elevated to a completely new plateau.
Placing the Speakers
In my particular listening environment, I discovered that the Salon2s were in need of lots of TLC during the set-up phase. Finding the right place for them and then proceeding to positioning them for best performance was a bit more of a task than I had anticipated.
The locations where the Salon2s sounded the best ended up being situated about a foot or so from where the other speakers had been placed. I know that because the area where the speakers are placed the floor is carpeted and because the Velcro strips I use to mark the position of the speakers were still in place. I can tell you that based on many experiences, using Velcro is far more convenient than relying on tape to mark component placement on a carpeted area. With Velcro, there is absolutely no residue of glue, something that is an absolute given with tape, especially in the long term.
What I found quite daunting during the placement period was the need to have the spikes for the speaker in place. I tried to move the speakers about without spikes, but found, as time progressed, that this speaker "wanted" to be on the floor with the spikes in place to sound its best, even during the set-up phase. Maybe it was because I have a tile covered concrete floor under the carped and the pad, but the whole demeanor of the speaker changed for the better when the spikes were implemented. As can be imagined, this made moving the speakers during adjustments to be quite a task. On top of that, the speaker is quite sensitive to small movements in location as well as small angular changes when searching for the right toe-in. For best performance in both locations, I ended up with the speakers pointing just over my shoulders.
There are a couple of issues that I want to note. I am fully aware that the Salon2 is a speaker that would be more comfortable in large rooms. My listening room could not be called large by any stretch of the imagination and a situation where I end up quite close to the speakers. And that is where the very high position of the Salon2 tweeter comes into play. Or, actually, does not come into play. You see, because of the tweeter location near the top of the enclosure, its axis is pointed above my head and I do not get the full measure of the high frequencies. Had I not remedied the situation by elevating my couch by 8 inches I could not have enjoyed the Salon2s to their full capability. In addition, I also tilted the speakers slightly forward, and therefore pointing the tweeter downward. This was accomplished by slightly extending the rear spikes and retracting the front ones.
I found the Salon2 to be an exceptionally remarkable product. What sets this loudspeaker significantly apart from the crowd, is its ability to perform with great finesse and extraordinary ease no matter the dynamic demands or the complexities of the musical content. And, yes, all of the above applies while covering the sum total of the complete audio spectrum.
Note: The Salon2's driver-to-driver transitions have been implemented in a strikingly superior manner. When I refer to a particular driver it is only to point out its exceptional performance per se without any implication that that part of the spectrum was disconnected from the rest.
What made this review very daunting was the Salon2's innate ability to respond to everything that came its way: every track of every recording and every piece of associated equipment was instrumental, usually to a significant degree, in how it sounded.
There were times when I would find myself listening to a particular track and be disappointed about what I heard. But then when I would switch to more familiar material and, lo and behold, the sound would be thrilling with an abundance of newfound resolution and nuances as the bonus. The same was true with equipment changes. Every signal source, every DAC, and every amplifier change would very clearly register as a newfound sound characteristic.
My final impression, therefore, is based on an integration of all the countless various listening situations that I encountered during this review process.
As is the case with stalwarts of such high achievement, singling out particular performance factors becomes especially challenging. That the whole is more than the sum of its parts was never more true than in the case of the Salon2..
But since dissection is the name of the game, I'll get going with that which jumps out at me immediately: the Salon2 is one fast, dynamic, extended, singularly seamless and uncommonly uncolored loudspeaker.
Let's start with fast and dynamic.
This is one of the major reasons why I found the performance of the Salon2 to be exceptionally winsome. Its ability to be very comfortable in the face of a turbulent transient world went a long way to lending credibility to the sound the Salon2. The sheer suddenness of the snaps, crashes, blasts and impacts, and, when called for, the consequent extended decays that the Salon2s sustained, all had a very close relationship to that what we hear in the world at large.
Try as I may, I could not detect that this is a four-way design. The spectral balance was as smoothly integrated as it was extended. Nor could I discern any discontinuities along the Salon2's ample spectral bandwidth, discovering instead its performance to be exceedingly even-handed from top to bottom. This is a bearing that contributed to the coherent continuity that the Salon2 consistently communicates. What I found particularly gratifying was that this essential aspect remained steadfast regardless of how loudly the speaker was energized.
Did I say "uncommonly uncolored" earlier? Well, I think "Clean" will do just fine!
No matter, the Salon2 to me is a salute to clean and pure. Pure is actually what it is all about. It takes everything into consideration: definition, detail, dynamics and delicacy. Purity will as well contribute significantly to the connotation of the authentic and the credible.
For me it is this sense of marvelous clarity that, in combination with the Salon2's superior dynamic capacity, I find to be the foundation on which all the desirable fundamentals of this loudspeaker are built.
And it is this purity that allowed the midrange to shine and imbued the Salon2 with the ability to provide an astonishingly clear window to the performance. It was now possible to hear into musical presentations with great involvement thanks to the remarkable transparency that this speaker offered. Its refined resolution prowess revealed a whole host of desirable sonic particulars. Some brought out the exquisite timbral shadings, some revealed soundspace specifics to a better degree, while others exhibited dynamic shadings with touching tenderness.
No, it was not the transparency that electrostatics do so well. But the Salon2 comes pretty darn close. And when we factor in dynamic capability, the Salon2 is clearly ahead of the game.
What set this speaker apart from all the other speakers that I have enjoyed over the years was what took place at the low end and also the high end of the performance spectrum and how well these performance regions were integrated with the marvelous midrange.
I found the low frequency extension to be awe inspiring. Not only does the Salon2 reach way down, it does so with definition and authority. For low frequency extension to be meaningful, it must have dynamics with very low distortion. Better yet, have these refinements at the low frequency end blend seamlessly with the upper bass and continue on into the lower midrange part of the spectrum. From what I observed, the Salon2 did just that and with a great sense of ease to boot.
What the Salon2 could do dynamically, no matter the playback level, is by far the best that I have experienced in my listening room. It is one thing for a loudspeaker to go low and quite another to actually have might and power when reaching way down. Well, this is yet another area where the Salon2 shines. It can provide the power at low frequencies in a most assertive manner. This clearly defined might was rendered with great consistently and appeared as an essential part of the foundation of the music. The performance gained significantly when the low frequency portion was delivered in the lively and spectrally unabridged manner of the Salon2.
The Salon2 demonstrated similar refinement capabilities in the treble and the very high frequency region. Since the Ultima tweeter handles a spectrum that spans 4 octaves, something that's far and away more than any of the other drivers, it ends up performing the most work in terms of extension. What this wide tweeter response does accomplish is to move any resonance at the very outer reach of its bandwidth away from the audible frequency spectrum and prevents the resonance from intermodulating with the frequencies within the audible region.
It is safe to say that none of us can actually hear the very highest octave (20kHz - 40kHz) that this tweeter is capable of actually reproducing.
But whatever I could perceive was exquisite and stunning. Not only that, the blending with the rest of the spectrum was superb; for me, the most enjoyable treat of the tweeter was its luxuriant sense of ease and outright purity. Of special note was the tweeter's capability to maintain this high performance standard at really loud playback levels.
With the Salon2s loud, demanding works could be enjoyed to a significantly more satisfying degree. Now they could be heard with their challenging dynamics flowing and ebbing with all of their subtlety and resolution remaining part and parcel of the presentation. I have to tell you that when this kind of high frequency refinement is coupled to the kind of overall dynamic creed that is the Salon2s forte, the enjoyment of music reproduction elevates to a new level.
Take imaging, for example. I was captivated time and time again by the Salon2's ability to create an aura of not only a richly detailed lateral stereo image appearing between the speakers, but also with a tellingly defined dimensionality of depth. This ability to replicate complex cues in 3-D space allowed the Salon2s to summon up exceptionally vivid soundspace imagery.
Call it a mirage, or holography, but the Salon2s were capable of creating hypnotically haunting sonic specters. Without the Salon2's exceptional transparency as well as the superb detailing of instrumental and spatial textures, this kind of delicacy and insight could not be recreated to this level. It's a highly resolved vibrancy that contributed to the many instances where a palpably prominent space was established.
And the Salon2s did a disappearing act rarely experienced. For a speaker with as strong a physical presence as the Salon2, I found it remarkable that it could do its stealth act to this degree. On many an occasion I was startled to realize that the sonic image in front of me had actually been created by the seemingly non-existent speakers in the room.
Yes, I have experienced such disappearing acts before. The Eidolons I owned for eight years could do that superbly, as could the TAD Reference One speaker that I had the good fortune to review recently for another publication. Now that I am in the presence of another great speaker that does a great virtual job of staying out of the way of the musical presentation, I can't but be overwhelmed by the performance of the Salon2 in this area.
At this stage, as far as I'm concerned, the Salon2 is the stealth champion in my basement listening room.
The Final Say
It has been an immense pleasure to have enjoyed a product of this sonic sophistication on an extended basis. The Salon2 is an astonishing loudspeaker that combines a host of desirable sonic aspects into one persuasively performing loudspeaker and one that can take on all comers in the realm of high performance music reproduction in the home.
I have not experienced another loudspeaker in my listening room that combined as many positive performance aspects as constructively and satisfyingly as the Salon2 did, while remaining steadfast to the goal of presenting music in an uncommonly faithful manner.
This speaker will bring out the chills in most people with its refined demeanor, and yet it has a wild side: it will thrill those who thrive on being pounded and banged as well as those who enjoy coming as close as possible to the heft that a full-blown symphony orchestra conveys. At the same time, the Salon2 is capable of captivating the listener with its alluring ability to resolve delicate details and create those treasured moments of rapt involvement. This is a finely honed loudspeaker that is destined to please many people while covering the vast spectrum of musical tastes and the associated performance demands.
And you know something, the Salon2 has list price of $22,000. If you have read the whole review then you know how great a bargain the Salon2 really is. For me, it is a testament of what is possible when pricing is approached with realistic profitability in mind instead of attempting to impress with pricing numbers that may not have any bearing on actual value.
The Revel Salon2 has my highest possible recommendation. Arnis Balgalvis