Roman Audio Centurion Loudspeakers
 About seven years ago, I moved
away from God's own borough and discovered I needed something that, like good manners, is
considered essential everywhere but New York: a car. This inevitably led me to discover
how bad most car audio was -- mine most certainly included -- and I set off on a mission
to discover whether there was such a thing as high-resolution car hi-fi.
Attending the IASCA (International Auto Sound Challenge
Association) finals, I discovered that high-resolution mobile audio certainly did
exist (a point many hardcore audiophiles refused to even consider). Yes, there were a lot
of maximum-dB-pumpin' bass-heavy monsters, but there were also some amazing car
stereos that had tonal accuracy, soundstaging, realistic dynamic range, and all the other
components that create audio goosebumps.
I also discovered, however, a very different mindset from
that of the usual home hi-fi enthusiast. The average high-end audiophile reacts to
equalization, extra speakers, and most forms of DSP the way vampires greet the dawn --
that is to say, with concern and alarm. Most mobile-audiophiles embraced those items as
necessary antidotes to a far-from-perfect listening room.
Then I met Dale Fontenot. His car eschewed all of that:
Relying on Cabasse drivers, tube amplification, and thousands of hours of
crossover/driver-placement tweaking, he produced a car audio system that gave my reference
system a run for its money.
Over the years, I continued to run into Dale at IASCA
finals, Consumer Electronics Shows (CES), and the various Home Entertainment shows
co-hosted by Stereophile. One day, I got a call from him. "Wes, I've just
heard Ray Kimber's DiAural circuit and you have got to hear this thing -- it is
absolutely amazing! You've got to check it out -- and, by the way, I've just licensed it
for my own speaker-building company."
"!!?"
The Roman Conquest was, however, a Good Thing
If there's one thing the world doesn't lack, it's small
speaker-building companies. When I was commissioning product reviews for Stereophile,
it seemed as if every table saw sold must have come with a how-to manual called So You
Want to Start Your Own Speaker Company. What on earth made Dale think he should start
one?
First, there was his 25 years of speaker-building
experience, not to mention his retirement, which gave him time to devote himself full-time
to the hobby that had given him so much fulfillment. Of course, there was also his
discovery of the DiAural circuit and his missionary zeal to promote the technology. But
more than anything else, there was his passion to produce the kind of loudspeakers that he'd
like to buy.
The DiAural crossover circuit was developed by Kimber
Kable's Eric Alexander and is being marketed and promoted by Ray Kimber and Bruce Bastion.
The process (or circuit or technique -- pick one) is designed to eliminate what its
promoters have dubbed "Doppler-encoding distortion." This is the tendency of low
frequencies to interact with (modulate) upper frequencies when reproduced by
multiple-driver loudspeakers.
Doppler encoding happens when a microphone records music.
If, for example, a low note and a high note are produced at the same time, a microphone,
using a single diaphragm, has to capture both the high frequency's rapid vibrations and,
at the same time, the low frequency's slower ones. In reality, the slow pulses of the low
frequencies cause distortions in the rapid ones of the highs.
If you were to play your recording back on a speaker that
used only one driver, the Doppler-encoding distortion of the high frequencies would be
canceled out by the driver's reproduction of the low tones. However, in a multiple-driver
loudspeaker (such as a simple two-way design), the speaker's crossover separates the highs
from the lows, sending the highs to the tweeter and the lows to the woofer. As a result,
the highs aren't modulated by the woofer's motion -- and the speaker reproduces the
Doppler-encoding distortion.
DiAural crossovers combat Doppler distortion and several
other common speaker colorations using only a few common electronic components. Each
driver reproduces only its assigned frequency range, but all of them are modulated by the
full-range signal -- which means the Doppler distortion is effectively cancelled.
Another problem common in speakers utilizing crossovers
(which is almost all of them) is called phase-shift distortion. Phase refers to a signal's
timing, and the shift is the amount of delay that occurs when the signal passes through a
crossover. Each order of crossover introduces a 90-degree phase shift (first order is 90
degrees; second order is 180 degrees; third order is 270 degrees; fourth order is 360
degrees -- or no apparent shift). When two drivers are 180 degrees out of phase, they will
cancel each other whenever they produce the same frequencies. Phase-shift problems are
most severe in second-order (and sixth-order!) crossovers, but they are frequently also a
problem in multi-driver speakers, which use several two-way crossovers.
DiAural crossovers keep the drivers in the same phase
quadrant from 20Hz to 20kHz.
In addition, keeping the drivers in phase at all
frequencies makes the off-axis signal and polar response much more coherent. And there are
other benefits as well: Because the woofer protects the tweeter (and vice versa), the
speaker is more bulletproof; the impedance-versus-frequency curve flattens without
changing the frequency response. Sensitivity also increases, the company claims, while
efficiency stays the same.
There are some tradeoffs, however. The speaker designer
loses the ability to fine-tune each driver's response in the crossover, which means the
drivers must be extremely well designed and made. And the speaker can no longer be
biwired, either. However, the DiAural circuit supposedly produces more of an improvement
in a speaker's sound than biwiring tends to -- and since the tradeoff saves the
manufacturer (and consumer) money on wiring and connectors, that almost seems like a plus.
Dale Fontenot was one of the first converts to DiAural.
"When I first heard it at the 1998 CES -- Ray Kimber just happened to be
demonstrating it with a Cabasse tweeter and Cabasse woofer I had been experimenting with
-- he was getting sound that I literally couldn't believe."
For the duration of the show, Fontenot would seek out the
best-sounding speakers on demonstration and then rush back to the DiAural demo to confirm
his initial response. "Finally, I signed the non-disclosure form and got a look at
the circuit. I said to myself, 'There's just no way this will work,' but I went home and
built two speakers with the same drivers -- one had a 24dB/octave crossover with the
finest military-grade components available, the other was a plain-vanilla basic DiAural
circuit. I've been sold on DiAural ever since."
Let’s do it after the high Roman fashion
The Roman Audio Centurion is the lynchpin of Roman Audio's
product lineup -- the others include the stand-mounted two-way Senator, the Pro Consule
center-channel speaker, the Gladiator subwoofer, and the Vesuvius subwoofer -- a monster
with a 21" inverted-dome woofer that offers response down to 14Hz! There's also a
dedicated HT system, the Home Cinema series.
The Centurion is a ported two-way floorstanding system. It
stands 38" tall and has a footprint only 16"D x 10.5"W. Its baffle slopes
back at an angle, offering time-alignment between the two drivers, both sourced from
Cabasse -- a 1.5" hard-dome tweeter and an 8.4" midrange/bass driver. Inset
flush into the 10.5" x 11.75" top plate is an elegant marble tile -- my demo
pair (in Galaxy Crème) sports vividly veined samples of what looks, to my untutored eye,
to be Turkish Rosalia. The speaker utilizes a down-firing Polk-developed Power Port --
four metal posts lift the cabinet above a baseplate, which uses four PolyCrystal Speaker
Spikes to decouple the Centurion from the floor.
The cabinet itself is hand built and rigidly braced. The
baffle is twice as thick as the sidewalls and damped with lead and asphalt-based material.
The cabinet's edges are rounded to minimize edge-diffraction and the drivers are flush
mounted. Internal wiring is Kimber Kable, the coils are sourced from Goertz, and only
hand-matched Niles resistors are employed. There are no capacitors. WBT binding posts are
standard. The Centurion is available in piano-black lacquer and a color Dale calls Galaxy
Crème -- he matched a paint chip from a '63 Galaxy to obtain its warm butterscotch glow.
The Centurion costs $5995 USD per pair.
A Roman thought hath struck him
During my audition of the Centurion, I employed a variety
of different amplifiers, ranging from the 25Wpc Music Pumps to Ayre's V-5 and V-5x,
Linn's Climax Twin, Simaudio's Titan (in two-channel mode), a pair of Musical Fidelity
M250 monoblocks, and Aloia's ST 15.01i. Just for fun, I also connected Linn's Classik music system (a fantastic
match, by the way).
Preamps included the Music Purse, the Conrad-Johnson
Premier 16LS, the Monolithic
Sound PA1, and my old standby, the Ayre K-1x. CD spinning was
accomplished by the Musical Fidelity Nu-Vista 3D CD player and the Audio Research CD3. Wires
were Shunyata Research throughout: Taipan power cables, Lyra speaker cables, and Aries
interconnects.
Si fueris Romae, Romano vivito more
The first things I noticed when I took delivery of the
Centurions were the grilles, which are set into a bulky oval wooden frame. They just
didn't match the elegance and precision of the rest of the speaker. I don't generally
listen to speakers with the grilles on, so I had no problem packing them away in the
Centurions' cartons and sending them off to storage. But those large hard-dome tweeters
are finger magnets, so I don't know what you should do if you have kids or unrepentant
tweeter-pokers in your household. Designing a handsome, non-sonically-obtrusive grille is
a real challenge -- I can think of few high-end speakers that have really solved that
problem.
At 85 pounds each, the Centurions aren't really hard to
move around, but their slick lacquer-like finish and smooth, rounded corners don't make
carrying them easy -- your best bet is to leave the PolyCrystal spikes off until you have
jockeyed them into something approaching their final position. In my room, that was about
42" from the front wall and a similar distance from the side walls, pointed straight
ahead (no toe-in). It's more important to give these babies lots of room to breathe than
it is to attempt bass-response reinforcement with near-boundary placement.
It's also important not to take their 93dB sensitivity
measurement too literally. I was able to drive the Centurions with the 25Wpc Music Pumps,
but the Pumps could not extract the effortless low-end response supplied by the Ayre V-5x
(150Wpc), Linn Climax Twin (100Wpc), or Musical Fidelity M250 (250Wpc). I suspect that the
same resistors in the DiAural circuit that make the tweeter and midrange resistant to
overloading also make them harder to actually set in motion (or something like that). Of
course, I've never been a microwatt kind of a guy, so SE triode enthusiasts should
probably take my caveat with a grain of salt and listen for themselves.
If you're not able to make the Roman Audio Centurions sing,
live, and breathe, you should probably examine your system for weak links -- once I had
them set up properly and fed 'em a high-resolution audio signal, they were astonishing
musical performers.
Early on in my audition of the Ayre V-5, I was in love with
the Centurions' open and transparent sound -- and amazed at how vast their soundstaging
seemed from almost anywhere in the room. Nevertheless, they seemed lightweight to me. They
were willing enough, but they just didn't give music -- even solo acoustic guitar -- its
physical presence.
Well, I thought, how much bass do you expect from
an 8" woofer? But the Centurions aren't small loudspeakers and they do cost $6000
-- surely they shouldn't need to make excuses for their performance. And they didn't.
When Ayre upgraded the V-5 to the V-5x, I learned for
myself the importance of that lesson three paragraphs above -- I shouldn't have blamed the
Centurions for a problem in the amplifier. Their bass response is just about the best I've
ever heard from an 8" woofer: tight, deep, and immensely tuneful.
Notes tremendous from her great engine thundered out on
the Roman air
While I'm touching on driver matters, I should mention that
I've never been wild about two-way designs built around 8" woofers, feeling that
whatever they've gained in bottom-end extension over a 6.5" driver, they've
sacrificed in agility. But before encountering the Centurion, I'd never heard a two-way
that paired such a large tweeter with an 8" driver.
It makes a difference, of course, in the crossover point. A
typical two-way with an 8" woofer and a 1" tweeter would probably cross over at
about 3kHz (between three and four octaves above middle C); Roman Audio doesn't specify
the crossover frequency of the Centurion, but it has to be an octave below that. As far as
the reproduction of fundamental tones is concerned, it doesn't make a lot of difference --
except for the very top of the range for violin, harp, clarinet, and flute (and piccolo),
most instruments don't sound above 1.8kHz. That’s not to say there's not sound at
that frequency; there is. In fact, that's where the complex harmonic overtone structure
that truly defines an instrument's sound is happening -- and that's where an 8"
woofer is getting beamy and screechy. Taking that load off the woofer makes an amazing
difference in a speaker's dispersion and freedom from strain.
This explains -- hey, I'm guessing here -- why the
Centurions throw such a huge soundstage no matter where you sit. It's almost certainly why
they sound as free from strain as live music does -- they just ain't straining.
What's that? You've never heard a speaker strain? Actually,
you probably have -- if the sound gets hard, constricted, and tight-arsed, chances are the
speaker's straining. The Centurions are the complete opposite of that. They sound natural,
open, and rhythmically supple.
I first began to notice just how accurately the Centurions
conveyed pitch definition and timing when I began to obsess over scat singing. I was
listening to an early Louis Armstrong side, "I'm a Ding Dong Daddy (From
Dumas)," (Louis Armstrong: 1928-1931 [Nimbus HRM-6002]), a typical piece of
disposable Tin-Pan Alley schlock that the peerless trumpeter was apparently forced to
record by his record label. Satchmo was so unimpressed by the material he apparently
didn't even manage to remember its lyrics. When the second verse rolls around, he starts
out confidently, "I'm a ding dong daddy from Dumas and you ought to see me do my
stuff/I'm a ding dong daddy from Dumas and . . ." We have no way of knowing now
whether he'd planned this next part or not, but it sounds as though he suddenly realizes
he hasn't got a clue beyond that, but that doesn't stop him for an instant. Without -- you
should pardon the expression -- missing a beat, he continues, "and I done forgot the
words and I don't know." He then proceeds to sing the words "ding" and
"dong" as though playing one of his astonishing trumpet solos. If jazz is the
instant art, then Armstrong created a powerful piece of it that day in 1930. (Armstrong is
credited with "inventing" scat on 1927's "Heebie-Jeebies," but I've
always loved "Ding Dong Daddy" because of the way it illustrates his grace under
pressure, not to mention his talent for creating something from nothing.)
Now the thing about scat singing is that it relies on
incredible timing and pitch-precision or it's just a bunch of "oobie-doobie"
nonsense. There aren't many singers who can pull it off -- and there are a lot fewer
loudspeakers that you think that do it justice. The phenomenal clarity of the Centurion's
presentation of "Ding-Dong Daddy" had me running to my record collection for
great examples of the art.
There's Ella, of course. So, I cued "Mack the
Knife" from Ella in Berlin [Verve 825670] -- which, like "Ding-Dong
Daddy" is an example of what panic can do, since the incomparable Ella forgot the
lyrics to the song and substituted her own (including a spot-on Satchmo impersonation).
Equally compelling is that concert's closer, an epic "How High the Moon" in
which she quotes Charlie Parker's "Ornithology" solo. The ways she toyed with
time and pitch were perfectly portrayed by the Centurions -- as was her remarkable range.
Simply amazing!
But best of all was Sheila Jordan's remarkably haunting
rendition of Louisiana governor Jimmie Davis's "You Are My Sunshine" from George
Russell's The Outer View [OJCCD-616-2]. Jordan never possessed the marvelous
instrument Fitzgerald had, but she worked every bit as hard at expressing herself through
the medium of scat -- and this performance manages to pack passion, pathos, and profundity
into a song few people would suspect capable of them. And again, the Centurions' ability
to contrast the huge sound of Russell's nonet against Jordan's small voice played a major
role in presenting the song as the musicians performed it. Possibly even more important,
the speakers delivered the dynamic extremes and all the shadings between them -- and
that's where much of the pathos lay. Think you're a hard sell? Listen to Jordan's
"You Are My Sunshine" through the Centurions and then tell me -- after
you've composed yourself, of course.
Who is here so rude that would not be a Roman?
The Roman Audio Centurions can't really be criticized for
anything they do, but they aren't perfect for all their virtues. They don't have the truly
deep bottom-end extension and authority of speakers with multiple woofers, for instance.
Nor do they have the phenomenally refined sound of, say, the Dynaudio Evidence Temptations
(few speakers do). On the other hand, I can't really think of any speakers in their price
range that can outperform them. They remind me a lot of B&W Nautilus 802s, except I
found them easier to drive and more rhythmically supple; they had a lot of the same
pitch-precision as the original Eggleston Andras (I haven't yet auditioned the Andra II, I
hasten to add), except they lack the Andra's bottom octave -- as well as their
only-one-distance-delivers-phase-coherence listening position restrictions; and they have
the balanced tonal presentation of the Gershman Acoustics Opera Sauvage with a much
smaller footprint. That's elevated territory -- not a speaker under $11,000 per pair --
but that's where the Centurion deserves to be.
This was the noblest Roman of them all
I found Roman Audio's Centurion easy to tumble for, but
hey, I'm easy.
You can tote it up for yourself. They are relatively easy
to drive and their DiAural crossover makes 'em hard to kill, so they play well with just
about any amplifier that delivers over 50Wpc. They have a huge, seamless presentation of
music -- one that preserves dynamic variations and absolutely honors pitch accuracy. They
are compact, physically quite presentable, and packed with high-quality audio jewelry.
They aren't cheap, but they're handmade (always
expensive) in limited quantities. That might not be your idea of value, but in
their defense I'll point out that they aren't expensive compared to speakers offering
similar performance.
They are only available in limited quantities, however --
and, unless you want to buy a pair via mail order direct from Dale Fontenot, you won't
find them easy to audition. Perhaps that will change as the word gets out.
There is, of course, the fact that Roman is a small company
and a relatively new one. No matter how good a product is, these are perilous times for
small businesses and some customers will prefer to deal with a larger manufacturer -- one
they feel will be around for the long haul. Fair enough, although I have a feeling
Fontenot is in the speaker-building business for good.
I certainly hope so. If the Centurion is an example of what
he is capable of now, I just can't wait to see what he can come up with when it's
time for him to make a statement product.
...Wes Phillips
wes@onhifi.com
Roman Audio Centurion Loudspeakers
Price: $5995 USD per pair
Warranty: Five years parts and labor
Roman Audio Systems
3828 Lay Avenue
Groves, TX 77619
Phone: (409) 962-0498
Fax: (409) 962-8554
E-mail: romanspeakers@aol.com
Website: www.romanaudio.com
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