| The Harbeth Super HL5 Loudspeaker |
| A
Masterpiece of Speaker Design Art |
| Paul Szabady |
|
October 2004 |

Every once in a while in the endless
flux of audio components, one encounters a
truly great musical performer. The Harbeth
Super HL5 loudspeaker is one such product. The
HL5 has been in production since 1977, eons in
the often-faddish world of audio. Now, in its
sixth iteration, it remains both
state-of-the-art contemporary and part of a
glorious loudspeaker design tradition that
traces its roots back to the BBC-inspired
research that was partly responsible for what
can be called the classic British loudspeaker.
The classic British loudspeaker has
consistently been a deep source of musical
pleasure, particularly so on orchestral and
acoustic music. Its hallmarks have been a
sweet and neutral tonal balance, free of the
harshness, artificial brightness and edge that
still are the main audiophile complaints about
the sound of their systems, and a pure and
true-to-timbre midrange neutrality that allows
listening for hours without aural fatigue.
Refined and subtle, CBLs often seemed as if
they had ugliness filters installed, so easy
on the ear were they.
Such results do not happen accidentally, nor
are they strictly the result of market
demands. The roots of one branch of the
classic British loudspeaker tradition anchor
into the need for the British Broadcasting
Corporation to have standardized and neutral
monitor speakers available for all its
recording and broadcast activities. The
BBC-funded research into loudspeaker design
led to a wide-ranging investigation of the
science of loudspeaker design, including
cabinet construction, damping, and the
acoustic properties of various driver
materials. The research spurred a very
talented team of designers and engineers who
later formed companies of their own to
manufacture the classic BBC monitors under
license, and to continue research and
development further in their own speaker
designs. Rogers, Spendor and Harbeth are the
speaker companies most closely associated with
this BBC tradition. Dudley Harwood, the “Har’
of Harbeth, was at the core of that very
talented original BBC team. Though Harwood
sold his company some years ago, Harbeth,
through its current owner Alan Shaw, has
remained faithful to the company’s ideals and
proudly maintains the best traditions of the
classic British speaker.
Much of the continued excellence of the
Harbeth speaker line stems from their research
into the properties of the plastics used in
building cones, expanding and continuing that
seminal BBC research that once led to the
first Bextrene-coned drivers. Harbeth’s superb
and patented RADIAL™ bass/midrange driver is
the fruit of this research; its most current
incarnation is incorporated into the Super
HL5. Harbeth claims state-of-the-art accuracy,
neutrality, and freedom from spurious
colorations and artificial resonances. Music
lovers and audio critics have agreed: the
RADIAL™ driver has received worldwide praise,
being hailed by many as the best midrange cone
driver available.
The Super HL5 is Harbeth’s largest domestic
speaker and, at $3895 per pair, its most
expensive. Weighing 36 lbs. each and standing
25 inches tall by 12 inches wide by 13 inches
deep, the HL5’s cabinet is finished with the
customary quality that has been a mainstay of
UK loudspeakers. Cabinet design and
construction are also based on BBC-research
findings. The HL5’s cabinet is cleverly
constructed and tuned to place resonances into
non-obtrusive frequency areas, aided by the
multiple cabinet screws on the front and back
panels that trace their origin back to the
days of easy field repair for BBC monitors.
The speaker belies the sophistication of its
cabinet design by its unassuming presence in
the listening room. If you’ve really got it,
you don’t have to flaunt it.
Harbeth did not design the Super HL5 to be
overly sensitive to stand design. I used 2
different pairs of wooden speaker stands to
raise the cabinets to properly match the HL5’s
tweeters to ear height. Stillpoints Universal
Resonance Dampers were used to isolate the
speakers from the stands. The HL5’s grills are
designed to be left in place during listening
and complete the speaker’s stealth room
presence.
The Super HL5 is a 3-way design, though
unusual in that its third driver is a
super-tweeter. Two SEAS metal-domed tweeters,
an aluminum one-inch tweeter and a titanium
one-half inch super-tweeter cover the top
octaves; the 200 mm RADIAL driver handles the
midrange and the reflex-loaded bass down to a
claimed minus 3dB point of 40 Hz in free
space. Although the speaker can be bi-wired, I
followed the recommendation of Harbeth’s US
importer and ran the speakers with single
wiring.
The consistent and lasting impression of the
Super HL5 is its exceptional ability to get to
and to communicate the heart of music. Never,
at any price or design type, have I heard a
speaker that so completely got out of the way
and let the music speak for itself. Never have
I heard a speaker that exceeds the HL5’s
ability to reveal the artistic quality of the
music and its performance. Never have I heard
a speaker that does so many of the
fundamentals of music reproduction so right:
timbre, rhythm, phrasing, articulation,
parsing, dynamic flow, sound stage
reconstruction, placement of instruments, and
the delineation of the ambience of the
recording site are all produced with an ease
and natural-ness so convincing and so adept at
evoking musical gestalts that immersion into
the music was as easy as breathing.
The quality of the Harbeth RADIAL™ driver is
at the heart of this remarkable achievement.
Harbeth’s painstaking research, development,
and implementation have indeed paid off. Since
90% of music lies in the midrange, getting the
midrange really right is essential. The
Harbeth’s reproduction of instrumental timbre
is exceptional, among the best I’ve ever
heard. I ran through my acid-test orchestral
LP’s, including Britten’s Guide to the
Orchestra, Rimsky Korsakoff’s Capriccio
Espagnole, and Ruggiero Ricci’s The
Glory of Cremona on which Ricci plays a
variety of classic violins from the great
violin-making center. Each instrument of the
orchestra was immediately identifiable, and on
Ricci’s record, the differences between the
Amatis, Stradivari and Guarneris were obvious.
Finally I randomly chose a classical LP,
played it without looking at the title and
tried to identify the instruments “blind.” The
Harbeth passed this difficult test with flying
colors.
To get timbre really right demands that the
driver(s) reproduce the initial transient
correctly and properly sequence in time the
expansion of the note, thus revealing its
harmonic structure and pitch. While initial
transient speed seems paramount, equally
important is coherent release in time and
correct volume tracking: any note will have
multiple degrees of loudness occurring
simultaneously. Correct reproduction and
identification of its timbre and the
instrument playing the note depends on
reproducing the proper relative volume of each
overtone correctly. As important as the
initial attack and expansion is, correct
volume tracking of the note’s decay must be as
good. Notes have to start and stop coherently.
The more instruments playing, the more
fiendishly difficult this tracking becomes.
Where the RADIAL™ driver truly excels is in
its ability to clearly reproduce many
differing volumes of sound simultaneously.
This not only nails the tone and pitch of each
note, but also recreates the flow of volume
and dynamics between notes: you hear not only
the identity of the instrument, but also WHAT
it is playing and HOW it is doing it. The
Super HL5 achieves the Holy Grail of music
making: it reveals inescapably WHY the notes
are doing what they’re doing. It manages to do
this with as many instruments as are playing,
extremely important in guaranteeing that the
larger whole of musical movement and argument
is conveyed.
Of course, a state-of-the art midrange driver
cannot do all this by itself. It has to be
loaded into a cabinet that does not color its
output and be integrated with treble drivers
of equal quality. The Super HL5 does this with
terrific coherence. I could not identify where
the crossovers to the tweeter and
super-tweeter occurred, the high frequencies
sounding like the natural extension of the
RADIAL™ driver. The Super HL5 speaks with one
voice. The high frequencies are simply
wonderful: no edge, no false brightness, no
‘metallic’ artifacts from its metal high
frequency drivers.
Unlike some classic British loudspeakers, the
HL5 did not sound too polite, too reticent, or
endowed with too stiff an upper lip. Music
emerged with its natural vivacity and élan.
The coherence of the RADIAL driver with the
extended high frequency response of the 2
tweeters leads to a natural clarity and
resolution. The superb ability of the HL5 to
simultaneously reproduce a wide range of
volumes allows the low level information of
the acoustic of the recording space to emerge
clearly. This is no distorting Black Hole
“sound emerging from a pitch black
background”: the sound emerges from and fades
into the ambience of the recording site, as it
should.
The HL5’s do not have to play loudly in order
to come alive. They convey their musical
communication and resolution even at quiet
volume levels. This is very welcome, and
increasingly important as evidence mounts that
long-term exposure to sounds as low as 85 dB
(down from the 90 dB levels previously thought
to be the threshold) can cause hearing loss.
The Harbeth maintained its resolution, its
superb 3-D sound field recreation of the
recording site, and its sense of rhythm and
brio even at levels that allowed social
listening with conversation. You don’t need to
play them at hyper-volume levels to enjoy
them.
My long-time reference loudspeaker has been
the Sound Lab Dynastat. This
electrostatic/dynamic hybrid uses 6-foot tall
electrostatic panels from roughly Middle C
(250 Hz) on up, mated to a 10-inch woofer that
goes down to 27 Hz. Although it was a steal at
its original price of $2500 per pair in 1990,
its evolution through the years now places it
at $4770 per pair. Its overall clarity, speed
and resolution have made me very skeptical
about very expensive cone-driver speaker
designs. Although the better tweeters of the
past 25 years have come close to matching
electrostatic high frequency reproduction, no
cone driver is ever going to match the speed
of a thin, essentially mass-less membrane
driver, be it electrostatic, ribbon, or
whatever. Listening to the Harbeth Super HL5
in direct comparison with the Sound Lab
revealed that HL5 did not have the ultimate
transparency or speed of the electrostatic.
But the HL5’s utter coherency made this a
non-issue, leading to the challenging question
of just how much transparency is necessary. If
a slightly ‘slower’ design still reproduces
the gestalt of an instrument playing with
utter and convincing ease, is pursuing
ultimates an unnecessary exercise?
The bass response of the HL5, while described
in their product brochure as ‘warm,’ is more
aptly described as rich in tone rather than
austere or acerbic. The lowest bass notes of
the double bass were clearly rendered, and my
acid test of bass differentiation – Ron
Carter’s Piccolo, a live album where
Carter’s piccolo bass plays with Buster
Williams’ lower-pitched double bass – featured
both clear differentiation in pitch and the
tunefulness and rhythmic speed of their
interaction. My second audition room, 18 by 14
feet in dimension, augmented low bass even
further than my larger free-standing reference
room, and tightness of bass response varied a
bit with the quality of the 2 stands I used.
The overwhelming ultimate conclusion, however,
was that the use of Stillpoints underneath the
speakers made the biggest difference: not only
in the tautness and definition of the bass
region, but also in the overall coherence,
clarity, and musical brio of the speaker.
The HL5 proved a non-fussy, non-neurotic
speaker to use. It is very ease to drive, its
8 ohm load and 86 dB sensitivity complementing
a wide variety of amplifiers, from my antique
1960 EICO HF89 tube amp, to my middle 1970’s
Marantz 1060 integrated, and on through the
Rotel RB 980, Meitner STR55 and Crimson 630
power amps. The HL5’s have the rare and
near-magic ability to extract the best from
any electronics driving them. While
differences between electronics were clearly
differentiated, they were never in the
spotlight and did not interfere with musical
perception and flow. Speaker cabling had the
same effect: I tried 5 different cables, none
of which interfered with the Harbeth’s
strengths. I had particularly wonderful
musical and sonic results with the DNM/Reson
Solid-Core. Since this cable retails at $5 a
foot, users of the HL5 will not have to
mortgage their house to find a compatible
cable. Differences in turntables, arms,
cartridges, and phono sections followed the
same pattern: obvious delineation of the
differences, but a focus on the components’
strengths. While this might be misunderstood
as perhaps a lack of ultimate revealing
qualities, I think a more apt description is
that the HL5 is so right and has the basics so
well done that it’s hard to capsize its boat.
While $3895 speakers aren’t exactly pocket
change cheap (though compared to the insane
prices of many High End dynamic speakers they
are) the fact that the Super HL5 does not
require obscenely expensive electronics to get
them to sing makes them a very rational
product. Extremely musical and reasonably
priced products like the Rotel integrateds and
power amps, the Creek A50i integrated amp, the
Rega P2 turntable, Shure V-15 V xMR cartridge
and the DNM/Reson interconnects and speaker
cables will allow complete access to the
Harbeth’s compelling and magical musical
world.
The Harbeths successfully tread the finest of
balances between resolution and musicality.
The recording signatures of the Mercury, RCA,
Columbia, Argo, Philips and DG labels are
immediately obvious; yet never interfere with
musical communication. A long listening
session comparing performances of Beethoven’s
Eroica and Berlioz’ Symphonie
Fantastique revealed the Harbeth’s
aesthetic power: the quality of performance
was completely transparent, first-rate playing
completely distinguishable from the
second-rate and the also-ran. As a direct
access into art, the Harbeths are
unparalleled.
The conclusion is obvious. The Harbeth Super
HL5 is a true masterpiece of speaker design.
_____________
Specifications:
Transducer system: Vented 3-way loudspeaker
Drive Units: (Woofer) Harbeth 200mm RADIAL™
polymeric composite cone, antimagnetic.
(Tweeter) Custom 25mm ferro-cooled aluminum
dome. (Supertweeter) 20mm titanium dome
Neodymium magnet, waveguide face.
Frequency response: 40Hz - 24kHz ± 3dB free
space, 1m
with grill on, smooth off-axis response.
Sensitivity: 86dB 1W/1m
Amplifier suggestion: 25-150W
Nominal Impedance: 8 ohms nominal
Power handling: 150W program
Connector: Four 4mm gold-plated binding posts
(biwireable).
Dimensions (h x w x d): 638mm x 322mm x 300mm
Finish: Cherry, Maple real wood (standard).
Others available to special order.
Weight: 16.8kg each, 19.6kg packed singly
Special Features: AV ready with controlled
magnetic field and suitable for close
proximity to TV and computer screens.
Recommended listening: On stands at approx.
tweeter height
Technology: Low-Q critically damped crossover
SuperTunedStructure™, SuperGrilleT
Address:
US Distributor: Fidelis
303 South Broadway (Route 28)
Salem, NH 02079
Tel: 603 894 4226
E-mail: info@fidelisav.com
Website: http://www.fidelisav.com
Manufacturer: Harbeth Audio Ltd
3 Enterprise Park
Lindfield, Haywards Heath
W Sussex, UK
RH16 2 LH
Tel: 01444 484371
E-mail:
sound@harbeth.co.uk
Website:
http://www.harbeth.co.uk

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