Sigberg Audio SBS.1 Introduction
Sigberg
Audio is a newer company that launched in early 2020 and specializes in
high-end loudspeakers with a markedly different design philosophy. Their
loudspeaker systems are geared toward the two-channel crowd yet promote a
design that necessitates subwoofers. Historically, two-channel purists shunned
subwoofers as if they were the bubonic plague. Sigberg Audio’s sole loudspeaker (as
of this writing), the SBS.1, doesn’t even attempt deep bass and leaves that
range entirely to subs. There is certainly merit to this idea in that it allows
the loudspeaker to focus on the frequency range that doesn’t require a large
enclosure or massive excursion ability. In other words, it frees up the loudspeaker
to go for a wide dynamic range without the need for a large enclosure that
lower bass output would demand.
Sigberg
Audio also deviates from traditional hi-fi loudspeakers by making their
speakers self-powered, so no amplifier is needed. Not only is it self-powered,
but it also has digital inputs, so the user doesn’t even really need a
preamplifier or DAC; all they need is something with a volume control. If the
source player has volume control, such as a PC, they can hook the speakers up
directly to the source. Furthermore, no outboard equalization is needed since
the SBS.1s have a built-in 9-band parametric equalizer. Audiophiles
traditionally like to have their electronics to be as segregated as possible,
but Sigberg has taken the opposite tack and has consolidated much of the
electronics onboard the speakers. The SBS.1s can be used like typical powered
speakers as well and are likely to do so, but the choice is there to skip some
of the outboard electronics if desired for a minimal setup.
For
review today, we have the Sigberg Audio’s SBS.1 speakers. They are an upscale bookshelf loudspeaker and priced as such at over $7k/pair (pricing in pinned on the Norwegian Krone so other currencies will fluctuate, but the pricing should hover around $7k USD). But for this cost, shipping is included as well as all taxes and import fees.
The questions we
will ask in this review for such an unusual speaker are: what do these
medium-sized bookshelf speakers do to justify that kind of price? What
situation are they best suited for? And how well do Sigberg’s unusual design
theories pan out in practical use? Let’s now dig in to find out…
Packing and Appearance
The
SBS.1 arrived in a double-layered cardboard box and tucked in some stiff foam
stand-off pieces. The packing should be adequate for normal shipping practices,
but I do think that something of this price point might benefit from thicker
foam pieces just in case of an abnormally rough shipping transit.
Once
out of the box, the SBS.1 speakers present themselves as sleek black units with
a fine satin black finish. The edges and corners have a slight rounding and the
cabinet shape has a slight backward lean that combines to give them a
streamlined look that is a definite improvement over the standard oblong box
that most speakers use. The driver cones have a glossy sheen that stands out as
the aesthetic focus of the SBS.1 from an industrial design standpoint. There is
a small Sigberg logo at the bottom front of the speaker to help save it from
being too minimalist. The included grilles hide the entire front of the speaker
and do make them look a bit drab, but some people loathe the appearance of
drivers, so manufacturers must supply grilles. Overall, these speakers look
quite nice without being flashy, and I would call them elegantly restrained.
They would not be out of place in a luxurious decor, and their simple, sleek
styling would enable them to fit in almost any type of interior design.
Design Analysis
As
mentioned before, the SBS.1 speakers are active bookshelf speakers that are
intended to be used with a subwoofer. They are a 2.5-way sealed design that
uses a coaxial driver. Let’s get into the details by starting with the drivers.
The tweeter is a 1” silk dome embedded in midwoofer ,which is used as a
waveguide. There are two midwoofers; one of which is used in the coaxial driver
and one standalone midwoofer mounted below it. Coaxial designs have the
advantage of having the tweeter always be in phase with the midrange driver. One of the advantages of coaxial designs is that
the acoustic center of the woofer and tweeter remains the same irrespective of
where you are in relation to the speaker – above, below, left, right, or center
of the driver. That means the drivers are not only time-aligned on-axis, they
are time-aligned at any off-axis angle as well. With a typical speaker where
the tweeter is above the woofer, that is not true. When the speaker is
time-aligned on tweeter axis, standing above or below the speaker will place
you closer to the tweeter or woofer respectively, so the woofer and tweeter are
no longer time-aligned as the sound from the tweeter will arrive first. This
affects the phase matching between the drivers and causes peaks and dips in the
response.
Since the upper midwoofer shares the same bass range as the
lower woofer, the SBS.1 should be much more of an acoustic “point source”
speaker than typical. Most loudspeakers try to emulate a point source location
from the tweeter’s position. This is often done with mixed success. The success
of this approach is key toward getting all of the drivers to add up to a
coherent, unified sound. The SBS.1 takes this very seriously, with the coaxial
driver blending in with the midwoofer with no timing difference caused by
distance difference, since there is no distance difference. The midwoofer’s
shared frequency ranges also assists here because there is no crossover
transition where they could cause conflicts at any angle. The 600hz low-pass
filter on the lower woofer will enable both woofers to act as a single point of
acoustic emission since the center-to-center spacing of the drivers, which is
about 6.5 inches, is much less than the upper-end wavelength of the low-pass
filter which is 22.6 inches.
As was mentioned before, the midwoofers do not attempt deep bass
at all, and the low end of the response window for the SBS.1 is 90Hz (+/-2dB).
This brings advantages and disadvantages. The obvious disadvantage is the
speaker needs a subwoofer in order not to sound thin due to lack of deep bass.
That is a reasonable compromise because if you can afford these speakers you
can certainly afford a subwoofer or two. There are two big advantages of this design
choice both of which are directly related to that unyielding maxim of loudspeaker
design, “Hoffman’s Iron Law,” which essentially states that you can have two of
the following three attributes but never all three: smaller size, deeper bass,
or wider dynamic range. Most speakers trade each of those attributes to varying
degrees, but the SBS.1 goes in hard for small size and dynamic range at the
expense of deep bass. This means that these speakers should be able to get very
loud, and of course, that they are very reasonably sized. Their specs suggest
that they should get extremely loud for their size, but we will see for
ourselves in the ‘listening sessions’ segment.
The midwoofers use coated paper cones which can be a good material to reach higher
frequencies without severe breakup modes. The cones are attached to the driver
frame with a double-roll surround. Double-roll surrounds can often be used to
trade excursion for sensitivity, and that makes sense in this design which is
going for dynamic range over low-frequency extension. The midwoofers use some
beefy 4” diameter and ¾” thick ferrite magnets. That is fairly heavy-duty for
5.5” midwoofers, and it feels weighty (although what really counts is the
actual magnetic field strength in the voice coil gap rather than the magnet
size). The midwoofers also use a copper shorting ring to reduce distortion
products. The woofers are rated for 120-watt power handling (by the AES 2-1984
standard) and so make a good match for the onboard amplifiers.
Sigberg
uses a sealed cabinet which is another sensible design choice for a loudspeaker
that is intended to be used with a subwoofer. Loudspeakers with ports can often
have rapidly shifting phase responses around the port-tuning frequency range,
and that can make it difficult to get in acoustic phase with the subwoofer.
Sealed speakers tend to have a predictable phase response that is much easier
to integrate with subs. The cabinet has a 4-degree tilt, and this is for more
than just looks; Sigberg says this was done to provide slightly more
high-frequency energy into the room since the on-axis angle is tilted slightly
away from the listener. The paneling is made from ⅝” thick MDF. Each driver has
its own sealed compartment, and the amplifier is in a sealed compartment as
well, so the internal bracing network is very substantial with solid panels
sectioning the SBS.1 internally. Given that it is already a smallish speaker,
that ought to make the enclosure extremely rigid and inert. The driver
compartments are lined on all sides with a composite felt material that is a
much better damping substance that the usual polyfill. The premium build
quality adds up to a hefty little speaker here at 21 lbs. each.
The SBS.1 are the lowest noise active speakers I
have encountered to date.
As
powered speakers, the SBS.1s use some of the highest performing electronics
available. Each speaker uses three Hypex nCore amplifiers. These are
state-of-the-art class-D amps, which are some of the lowest distortion and
lowest noise amps around. In fact, these are the lowest noise active speakers I
have encountered to date. They are dead quiet unless you place your ear right
up against the tweeter where there is a very faint hiss. Each midwoofer gets
125 watts RMS and the tweeter gets 100 watts RMS for a system total of an
astounding 350 watts RMS per speaker. That is a lot of power for such a small
loudspeaker, and it should have a tremendous amount of dynamic range for its
size, especially considering that the drivers are rated to handle that much
power. The SBS.1 uses an active crossover, of course, and the crossover slopes
are not traditional ones. The tweeter/midwoofer crossover frequency is 2.5kHz
and the high and low pass filters start with a gradual 1st order slope but
become a sharper 2nd order slope as the filter progresses. Being a 2.5-way
speaker, the coaxial midwoofer shares the bass range with the lower woofer, but
the lower woofer gets high-passed at 600Hz. Sigberg tells me that this unusual
mixed order filter structure was done to improve the phase response.
The
SBS.1 has a variety of connectivity to accommodate most system types. On the
analog input side, there is a balanced XLR input and through, as well as
unbalanced RCA left and right inputs. On the digital side, there is an AES
input and through, a S/PDIF input and output, as well as a TOSLINK input. For
the digital inputs, there is a selector that lets you designate the speaker to
playback the left, right, or both channels, although the speaker pair come
preconfigured for left and right channels, so it shouldn’t be necessary to make
that selection unless you want to double-check it. Many digital sources only
offer a single S/PDIF or TOSLINK output, and in those cases, the user will need
to get a splitter to divide the signal into two streams. Digital audio signal
splitters can be inexpensive, but they are small and widely available, so that
shouldn’t present a problem.
The
SBS.1 amplifier has three preset response curves to choose from: Preset 1
provides a flat response, Preset 2 gives the treble a slight elevation to
compensate for grille use, and Preset 3 shelves the treble by a few dB for
those who prefer a warmer sound. Users also have the option of tailoring the
response to their own taste because the SBS.1 comes with a 9-band parametric
equalizer when they download the DSP software provided by Sigberg’s website.
Users will need to hook up the SBS.1 to a PC with Windows 7 or higher using the
provided USB cable to access the equalizer, but the equalizer was easy to use.
I would recommend most users to just stick with the provided presets for the
best sound unless they really know what they were doing with an equalizer. The
Hypex software package also allows the user to adjust other parameters such as
gain settings, standby settings, LED brightness, and a few other options.
The
SBS.1 speakers have an active limiter so they can be played loud without
worrying about overdriving the woofers. In my own listening, the amp was
somewhat warm to the touch at idle but never became hot even after higher-level
listening. Sigberg tells me that there are built-in thermal sensors that will
lower the maximum output by 6dB if they detect excessive heat, but that has
never happened in any of their testing. That is not surprising considering the
enormous efficiency of class-D amplifiers where much less energy is lost as
heat compared to class-A/B designs.
Listening Sessions
In my 24’ by 13’
(approximately) listening room, I set up the speakers with a few feet of
stand-off distances between the back wall and sidewall and equal distance
between speakers and my listening position. I experimented with toe-in angles
and ended up preferring the user manual’s recommended angle of the speakers
facing straight ahead in a parallel direction. The listening distance from the
speakers was about 8 feet. The subwoofer in use was the Sigberg Audio 10D
(review forthcoming).
Music Listening
For
an example of the SBS.1’s performance with orchestral content, I choose
“Symphony No.5” by Christopher Rouse. This wildly dynamic recording that I
found in 24bit/96kHz hi-res on Qobuz is released by the Naxos label and was
performed by the Nashville Symphony under the direction of Giancarlo Guerrero.
Rouse was a celebrated American composer whose style fell under the designation
‘neo-romanticism’ and has a distinctly American signature. Symphony No.5 is an
energetic and emotional piece that runs through a variety of moods and gives
every instrument a chance to shine. In fact, this 2020 release won the Grammy
for “Best Classical Contemporary Composition,” although sadly that occurred
only a year after Rouse’s passing. This world premiere recording was given the
excellent recording quality that the Naxos label is known for.
The
precision of the soundstage of the SBS.1 speakers was the first thing I
noticed. It was easy to tell through these speakers that the recording was done
with the microphone over the performing group. That doesn’t break the concert
hall illusion, although it doesn’t have the acoustic ambiance of a distant
listening position. Orchestral sections were easily defined in the soundstage
with much of the brass on the right side and much of the woodwinds on the left.
The different strings were localizable as well, with violins and violas more
toward the left and cellos and bass to the right. The effect was one of listening
at the center of a close row in seating. All the instruments sounded natural in
timbre, and there was no spectral tilt that I could discern. Dynamic range was
quite surprising considering the size of the speakers, although this wasn’t a
shock to me since I already knew the capability of the internal components.
Someone who wasn’t already familiar with the design of the speaker would surely
find their ability to tackle the peaks of the crescendos to be quite
astounding. The depth and the breadth of the presentation by the loudspeakers
left me nothing to complain about. With the inclusion of the subwoofer, it all
sounded very much like what would be expected of a large full-range tower
speaker.
Theprecision of the soundstage of the SBS.1 speakers was the first thing I
noticed.
For
something with an emphasis on a sole vocalist, I found a striking new release
titled “Lysbærer” by Nanna Barslev, again on
Qobuz. Barslev hails from Denmark and stays close to her roots by creating
Nordic folk music, although this is far too eclectic to categorize as just
‘folk’ music. There is an atmospheric and cinematic quality to it, but it would
be too emotionally charged to be labeled ‘new age’ music. Think Enya but with
war paint. This terrifically produced, hi-res recording is Barslev’s first
album, and I have no doubt it will propel her to greater heights. Hopefully,
any forthcoming music by her will maintain the artistry that she exhibits here
in “Lysbærer.”
The
album opens with an ethereal choral effect that sweeps across the soundstage,
and the width of the soundstage seemingly exceeded the span of the speakers’
placement. When the song’s verse hits, Nanna’s voice holds an anchored position
squarely in the center of the soundstage. The imaging was extremely
well-defined. Nanna was flanked by a harp and hurdy-gurdy playing (for those
who don’t know, the hurdy-gurdy is a medieval string instrument that always
sounds sorrowful- you have likely heard it in many movies set in the middle
ages). The percussion including the bass drum was sharply expressed, and the
transient behavior left nothing to be desired. Nanna’s voice was gorgeously
rendered and sounded full and natural. Studio effects sometimes lent her a
dreamlike quality such as in the intro for track 7, “Jagtmarker,” a
gradually-building passage that the SBS.1 speakers gave a monumental sensation
contrary to their moderate size. That story is true for much of this album; the
SBS.1 speakers were able to sound much bigger than they look. Of course, that
size disparity between looks and sound is due in large part to the subwoofer,
but the soundstage and dynamics were the speakers’ doing. “Lysbærer” sounded great on the SBS.1 speakers; other
speakers might offer a different presentation of this album, but not
necessarily a better one.
For
an audio experience like no other, I listened to “Doctor Belief” by Creme
Rinse. Creme Rinse is a Japanese artist who threads all kinds of audio samples
taken from a variety of media and strings them over original music and sonic
atmospheres to form a science fiction narrative that stretches over the length
of the album. As an audio collage used to create a cyberpunk setting, there is
a wide assortment of sounds used to keep things interesting. There is an
eclectic mix of music as well, although much of it is electro in keeping with
the futuristic theme of the album. Throughout the album, a story is ‘suggested’
that a criminal mastermind named Doctor Belief escapes a space prison and
inhabits people’s minds to compel them toward actions that create chaos
throughout the solar system. For those who are curious, the album can be had at
the recording label Seikomart’s Bandcamp page. This bizarre pastiche of
sound effects and music certainly wouldn’t be to everyone’s tastes, but it has
an imaginative sound mix that would show off the abilities of a high-end sound
system.
Sound
effects and spoken word samples were given a crisp reproduction by the SBS.1
speakers and were still perfectly clear even amongst Creme Rinse’s at-times
busy sonic mixture. The soundstage, bizarre as it is in an album like this,
came through with a dizzying effect. The soundstage would rapidly shift like a
quickly edited movie and would require the listener to reorient themselves for
every ‘cut,’ but the SBS.1 speakers were able to make it clear where these
transitions were. The music could pound through the speakers when asked for,
but they could also delicately reproduce the more relaxed and ambient medleys
when they came along. Indeed, they could give my room an utterly club-like
sensation at some moments, notwithstanding the sub’s contributions. Again, the
system sounded much larger than it actually was. This sound mix is quite heavy
in the use of bass, and, of course, the subwoofer carries some of that weight,
but most bass in both music and movie bass is largely mid and upper bass, so the
main speakers must be capable in that range as well. I am happy to report that
the SBS.1 was easily able to keep up with the Sigberg Audio 10D subwoofer in delivering a strong,
punchy bass. My guess is that this music was created using headphones primarily
and that it will primarily be consumed by headphone users, but it sure is a
kick to hear with such a high-fidelity sound system that Sigberg Audio has
provided.
the SBS.1 speakers gave a monumental sensation
contrary to their moderate size.
To
see what the SBS.1 loudspeakers could do at a loud level, I threw on Malux’s
“Motive” on the Vision Recording label. This six-track EP is just one
drum’n’bass banger after another. This is loud and aggressive electronic music
and was intended to be listened at higher levels. Incessant percussion,
growling lead synths, and bombastic bass are the stuff that this music is made
of. “Motive” is more than just repetitive dance music, however. There is
inventiveness in many of the sounds as well as a variation in the compositions
here that make it fun to listen to even if you aren’t out for a night of
clubbing. If music is going to make you go deaf, you might as well have fun
while doing so.
Given
the design of the SBS.1 speakers, I guessed that they would have an ample
amount of headroom, and I was not disappointed. The snares had a visceral snap,
the lead synths screamed uninhibitedly, and the razor-sharp sizzle of the hats
showed that the tweeter had no trouble keeping up with the midwoofers.
Likewise, the midbass of the midwoofers had no trouble keeping up with the
subwoofer. The system could easily get louder than I am comfortable with, and
my tolerance for loud music is likely a bit higher than average. I did not get
a sense that the system was being pushed into distortion, and everything
sounded clear as a bell. I am not sure if I reached the dynamic limits of the
speakers, but I sure as hell reached the dynamic limits of my ears. I enjoyed
listening to “Motive” on the SBS.1 speakers, but at such elevated levels, I was
also relieved that it was over. The designer tells me that the speaker is
heavily protected by electronic limiters and to go ahead and let them rip
because they can’t damage themselves. That being the case, I would say if you
are looking for something that can withstand irresponsible use of the volume
knob such as at a party where the alcoholic beverages are flowing freely, these
look to be a great choice; just try to put the speakers in a location where
drinks will not spill on their fine satin finish.
Movie Watching
One
movie that I decided to watch using the SBS.1 speakers was the latest
adaptation of “Death on the Nile.” I figured that an Agatha Christie whodunit
with an all-star cast would be a good demonstration of a sound system’s
dialogue intelligibility if there ever was one, but more than that, I generally
enjoy Agatha Christie stories, so this was something I was looking forward to.
A major movie like this one should have the best sound engineering that money
can buy along with a top-shelf original music score, so it should stand as a
good all-around test of a loudspeaker’s ability with film content.
“Death
on the Nile” proved to have a flashier sound mix than I expected due to the
heavily stylized direction, and the SBS.1 speakers were able to relay the
bombastic tone that the movie was going for. I would have thought an Agatha
Christie whodunit would be a bit more restrained, but I guess the story and
characters are not thought to be enough to keep an audience’s attention
nowadays. None of that can be held against the SBS.1 speakers which did an
admirable job of bringing about the intended sound of this movie. Dialogue
intelligibility was very good, and I had no problem understanding anything said
by the characters, not even Kenneth Branagh’s over-the-top Hercule Poirot (most
French people who have spent that much time in the English-speaking world do
not have such heavy accents). Patrick Doyle’s elegant music score stands out as
a highlight of this sound mix, and the SBS.1 speakers rendered it with a
properly cinematic depth and scale. They proved that even smaller speakers
could deliver a big-screen experience. I have had much larger speakers in my
home theater, and these two little speakers plus their diminutive subwoofer
partner didn’t leave anything to be desired as far as the sonic experience
went. There are few speakers of their size that I could be enthusiastic about
as a pairing for my 125” screen projection system but watching “Death on the
Nile” with this system proved that I could enthusiastically, live with it.
For
a sound mix with more emphasis on action, I watched 2021’s “Free Guy” starring
Ryan Reynolds. In this big-budget action-comedy, Reynolds plays a non-player
character in an open-world free-for-all game similar to “Grand Theft Auto”
series. To his shock, he becomes aware of the lowly nature of his existence but
then learns to use his plight to his advantage. While I had not yet seen “Free
Guy,” the premise sounded fun and should set the stage for a fantastical sound
mix that could be a great demonstration of the SBS.1’s ability to render
big-screen action.
I
watched “Free Guy” at a fairly loud level, and the SBS.1 gave a clean, dynamic
presentation. I enjoyed the movie and felt that the SBS.1 speakers acquitted
themselves beautifully for this lively and energetic sound mix. Effects, music,
and dialog were well-positioned in the soundstage of the mix using just two
channels, and I didn’t miss the center channel or surround channels at all. Of
course, a phantom center works pretty well when the listener is seated at an
equidistant location but not really anywhere else, so listeners with a wider
seating area would want to use a physical center speaker. One interesting
aspect of the SBS.1 is that you could turn it on its side for a horizontal
orientation, and the design suggests it would work just as well on its side as
upright, so if you needed a lower profile center, the SBS.1 could do that as
well as any other center speaker design. By the same token, if you needed lower
profile left and right speakers, you could use the SBS.1s on their side and it
shouldn’t give up a thing in terms of sound quality. That is just one of the
added benefits of its strong point source design. While I did not miss the
center and surround channels watching “Free Guy” on a pair of SBS.1 speakers
and the 10D sub, I do have to wonder how much the experience would be elevated
if I had an entire surround sound system comprised of SBS.1s. It would be
pricey, but I imagine that would have to sound tremendous.
