Thiel Audio - Audio Focus

ELECTRONICALLY REPRINTED FROM SEPTEMBER 2013
the home entertainment authority
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t e s t r e p o r t s s p e a k e r s
Thiel Audio
CS1.7 tower SPEAKERs / $3,999 per pair / by BRENT BUTTERWORTH
W
hat happens when a speaker company gets sold ? It depends. Definitive Technology is still doing pretty much the same thing 9 years after it was acquired.
Acoustic Research (AR), on the other hand, produced good speakers for 3 decades
after its original sale in 1967, yet the once-hallowed brand is now applied mostly to accessories. ¶ Thiel Audio was sold to an investment group just last year, so it’s too early to
tell, but at least the products haven’t changed. The new CS1.7 continues design concepts
that the company embraced in the late 1970s — specifically, a focus on phase coherence.
i l l u s t r at i o n b y K e v i n s p r o u l s
Most speakers alter the phase
of sound as the frequency changes.
For example, a 500-Hz tone might
start with the speaker cone pushing
forward, while a 5,000-Hz tone might
have its phase shifted so it starts with
the speaker cone moving backward.
In a typical speaker, the phase of
the sound might be flipped several
times as you go from the lowest to
the highest frequencies. In extreme
cases, this shift could cause some frequencies to be substantially delayed
relative to others.
Unless phase shift is radical, it’s
not readily audible. To my ears,
though, the few speakers that are
phase-coherent — maintaining the
same phase response, plus or minus
a few degrees, at all frequencies —
present a more realistic and dramatic
sense of space than non-phasecoherent designs do.
That said, phase coherence isn’t a
magic equation for sonic excellence,
because there are many trade-offs.
The shallow crossover slopes needed
to maintain phase coherence put
extra stress on the tweeter, potentially causing distortion or even
failure. They can highlight the woofer’s tendency to beam in the midrange
and create “cupped hands” coloration.
And they can increase interference
between the drivers, which leads to
inconsistent vertical dispersion. The
late Jim Thiel — the company’s chief
engineer for most of his life — openly
acknowledged these problems, and he
worked for decades to overcome them.
The CS1.7’s 1-inch tweeter and
6.5-inch woofer mount on a slanted
baffle, so their acoustical centers
are aligned vertically. The stampedaluminum, flat-diaphragm woofer is
said to be capable of smooth operation to 10 kHz, although it’s crossed
over to the tweeter at a very low 1.44
kHz. The unusual, slot-shaped front
bass port is designed to reduce air
Percussionist
Airto Moreira’s
agogô bells imaged
spookily about 2
feet from the inner
side of the left
speaker, nestled
in the sonic wash
of Keith Jarrett’s
electric piano like
a Chihuahua in a
beanbag chair.
turbulence and eliminate audible
port noise. Thiel says the heavily braced enclosure is 42 percent
heavier than the one used for the
CS1.7’s predecessor, the CS1.6.
Like other Thiel speakers, the
CS1.7 uses a first-order (–6 dB per
octave) crossover, the response of
which allows the drivers’ outputs to
sum without substantial phase shift.
The CS1.7 is also like other Thiels in
that its crossover uses extra filter
networks to smooth the frequency
response and achieve consistent
impedance at all frequencies.
Although a first-order crossover can
be done with just one capacitor and
one choke, I counted eight capacitors
and five chokes arrayed across two
separate circuit boards in the CS1.7.
Another trait the CS1.7 shares
with other Thiels is its flawless
craftsmanship, with gorgeous wood
veneering done at the company’s factory in Lexington, Kentucky. Let’s
hope the new owners never abandon
this tradition.
setup
I connected the
pair of CS1.7s to a Krell S-300i integrated amplifier (later adding a Job
225 amp), using my Firestone Audio
ILTW USB digital-to-analog converter and Pro-Ject RM-1.3 turntable
as sources.
In my experience, highly tuned and
tweaked speakers such as the CS1.7
almost always benefit from careful
experimentation with positioning.
First, I placed the pair in the same
positions I customarily use for tower
speakers, then backed them closer to
the wall until I got enough bass reinforcement to produce a satisfying
tonal balance.
Next, I experimented with toe-in.
I started with the speakers pointed
straight at me, but the tonal balance
sounded a bit bright in this position. So I tried pointing the speakers
straight ahead, parallel to the room’s
side walls, but this reduced the focus
of the center image and also muted
the upper treble response a bit. I got
the best sound with the Thiel speakers toed in a little bit more than
halfway toward me.
Thiel includes a set of heavy-duty
pointed feet for leveling the CS1.7.
The company also offers optional
“outrigger” legs that stabilize the
speaker — a good idea if young kids
are around, because the speaker’s
9.5-inch width makes it a tad tippy.
performance
My first Thiel speakers review — of
the CS2.2 tower and the SCS bookshelf — dates to about 20 years ago.
Back then and still today, Thiels had
a rep for highly detailed sound that
is best suited to more delicate music
like classical, folk, and jazz, but not so
good for rock.
Continuing my longstanding
tradition of starting with material
I think will sound bad with the
speaker under test, I cued up an MP3
download of “Dumb Disco Ideas” by
Brooklyn synthpop duo Holy Ghost!
(The exclamation point is theirs.)
With its jamongous ’80s-style drum
sound, a bass line that sounds like it
was swiped from a Cameo tune, and
the verdict
plus + Incredible detail + Dramatic ambience + Unsurpassed craftsmanship
minus – Not suited for heavy music or deep bass – A tad trebly at times
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t e s t r e p o r t s s p e a k e r s
key features
+ 6.5-in aluminum-diaphragm woofer + 1-in aluminum-dome tweeter
+ 36.5 x 9.5 x 11.8 in; 54 lb
test bench / fr eq r esponse
percolating keyboard effects soaked
in digital reverb, this is music
composed to play through crappy P.A.
speakers, not through $4,000-perpair audiophile speakers.
Heard through the CS1.7, however,
“Dumb Disco Ideas” astounded. The
phase-coherent design worked just
as much magic with EDM keyboard
squiggles as it did with acoustic
guitars on audiophile recordings.
The ambience wrapped my room,
the sounds swirled behind me, and
the bass pulsed deep and tight. I
turned the system up to the kind of
volume this music demands, then
pushed it further to see how loud
the CS1.7 could get before it sounded
raspy: about 98 dB from my listening
position, or about 6 dB louder than I
might usually listen.
This wasn’t what I was expecting.
Wanting to explore the CS1.7’s bass
dynamics further, I kicked over from
Holy Ghost!’s fake-’80s tune to a real
one: “What It Is” from Miles Davis’s
1984 album Decoy. On this recording, Miles, guitarist John Scofield,
and saxophonist Branford Marsalis
sounded natural and detailed. But
Darryl Jones’s explosive, thumbslapped bass line lost its impact, and
the sound got too thin.
While I was still in the Miles folder
on my laptop, I decided to play the
similarly titled “What I Say” from
1971’s Live-Evil — and suddenly, we
were back to amazing. Michael
Henderson’s finger-plucked bass
line proved no problem for the
6.5-inch woofer; in fact, it sounded
exceptionally precise and grooving.
Percussionist Airto Moreira’s agogô
bells imaged spookily about 2 feet
from the inner side of the left speaker,
nestled in the sonic wash of Keith
Jarrett’s electric piano like a Chihuahua in a beanbag chair.
The rest of my listening sessions
with the CS1.7 went like that. The
closer I got to heavy rock, like ZZ
Top’s “Chartreuse” (from the current La Futura), the more the CS1.7
sounded thin and trebly, more like a
mini-monitor than a tower speaker.
The closer I got to purist, minimalist
10 dB
0
-10
–20
–30
20 Hz
50
100
200
Tower 41 Hz to 20 kHz ±7.2 dB
500
1 kHz
2
5
10
20
recordings, like NYC avant-jazz
group Flip City’s self-titled debut, the
more the CS1.7 amazed. With that
last recording in particular, the CS1.7
completely blew me away, capturing
even the subtlest breaths and key
clicks of saxophonist David Aaron.
I did notice as I was listening to
Aaron’s tenor that the CS1.7 appeared
to have a little bit of a lower-treble
push — I guessed around 3 kHz —
which enhanced detail but also made
the sound slightly bright. Middleof-the-road pop music, such as Joni
Mitchell’s “All I Want,” from her
classic 1971 LP Blue, and my old Toto
fave “Rosanna,” also revealed
a mild tilt toward the treble on
the CS1.7.
bottom line
While the Thiel CS1.7 isn’t a speaker
that every listener will love, it’s not
intended to be. It’s a speaker for those
who want to hear every last sonic
detail and every subtle ambience in a
recording, and who want to feel like
they’re attending a live acoustical
performance rather than slumping
in a living-room recliner listening
to a hi-fi. In other words, it’s a Thiel
through and through. ••
The Thiel Audio CS1.7 measures differently from what
subjective impressions suggest, with a downward
(reduced treble) tilt in the tonal balance. The large ±7.2-dB
variance you see here is largely due to rolloff at very high
frequencies; with the measurement limited to 10 kHz,
response measures ±4.8 dB. Off-axis response is excellent: Below 10 kHz, the CS1.7 measures almost the same
at ±60° as it does at 0° on-axis. Impedance runs below 5
ohms through most of the audio range, so be sure to use
an amp with a 4-ohm power rating that’s double or nearly
double its 8-ohm rating. With 88 dB measured sensitivity
at 1 meter, though, the CS1.7 doesn’t need a whole lot of
power; even 50 watts would be plenty. Bass output is
decent for a speaker with a 6.5-inch driver, averaging
113.6 dB in the low bass (40-63 Hz) octave and 84.4 dB
in the ultra-low bass (20-31.5 Hz); you’ll get roughly 6
dB more output from a pair of CS1.7s. — B.B. // For more
Thiel lab data, go to soundandvisionmag.com or consult the
tablet edition of this issue.
Posted with permission from the September 2013 issue of Sound & Vision ® Bonnier Corporation. Copyright 2013, All rights reserved.
For more information on the use of this content, contact Wright’s Media at 877-652-5295.
103826
THIEL Audio Products ● 1026 Nandino Boulevard, Lexington, KY 40511
Phone: 859.254.9427 ● Fax: 859.201.9600 ● Email: [email protected] ● Web: www.thielaudio.com