| The Celestion F15 Bookshelf
Speakers |
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Pursuing the Cheap and Cheerful |
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March 2005 |

The rise of the Home Theater
phenomenon has made purchasing loudspeakers
for music playback fraught with peril. To
paraphrase Frank Zappa on the subject of
ponchos: “Is that a real speaker or is
that a home theater speaker?” Adding
sonic violence to already stupidly violent
Action Movies hardly strikes me as a viable
aesthetic for music playback. On the other
hand, overly laid-back and mellow speakers
that sink music into a Lawrence Welk
somnolence are an unsatisfactory alternative
to Boom and Sizzle ear-frying nastiness. There
is no inherent reason why HT should be so bad.
Whether one is reproducing intelligible
dialogue or the human singing voice does not
matter. The goals are cognate. I’m naturally
suspicious about HT speakers, especially when
reputable manufacturers produce HT lines that
are obviously inferior to their music-based
speaker lines. You can sense that their hearts
really aren’t into it.
There was been a revolution occurring in the
UK hi-fi world. Many classic and
quintessentially English companies are now
owned and manufactured by the Chinese: Quad,
Wharfedale and Celestion come most readily to
mind. One of the grand old UK speaker
companies, Celestion’s illustrious history
dates back to 1928, its founders having fair
claim to the invention of the dynamic cone
loudspeaker. Under their Chinese ownership,
Celestion speakers are designed and developed
in England and manufactured in China.
Most audio enthusiasts are probably familiar
with the Celestion SL 6, SL 600, and SL700
speaker series of some years ago; speakers
that pioneered the successful application of
the metal-dome tweeter (copper in the original
SL6) and Celestion’s highly sophisticated
aluminum-honeycomb cabinet construction
technology. Celestion’s application of laser
interferometry allowed visual scrutiny of a
driver’s behavior while actually producing a
sound. For the first time designers could see
if a driver was working correctly as a piston,
or had lost its marbles and was producing
trash. Most recently, Celestion’s inexpensive
“Number” series, particularly the Model 3 and
5, retailing at $289 and $399 a pair
respectively, set a new standard for
inexpensive speakers in rhythm, phrasing, and
overall musical sense. A recent comparison of
my own Celestion 3 MkII’s against a $7500 High
End monstrosity found the $289 speakers
outperforming the monsters by all musical
criteria. The Celestions created the magic of
music; the monsters just made sound.
Celestion currently produces two HT-compatible
speaker lines: the rather self-conscious
“Sound Style” line of plastic and metal, and
the “F” series with traditional wood cabinets.
The F Series is available in 3 wood finishes:
black ash, maple and dark apple. There are two
bookshelf speakers, a center channel speaker
and two floor-standing speakers. A subwoofer
is available. All are shielded. The F15 is the
larger of two bookshelf speakers.
My F15’s were finished on all sides in the
Dark Apple veneer, a very attractive and
rich-looking finish. The bookshelf F15 has a
partner in the floor-standing F20, which uses
the same drivers and lowers the –2dB point of
the F15’s 65 Hz to 55 Hz. Sensitivity is the
same at 89 dB. This raises the familiar
quandary of which speaker to choose: the
smaller, less expensive speaker which, with
its smaller cabinet less likely to resonate
a-musically, can more closely approximate the
Ideal Point Source; or the larger
floor-stander which does away with the need
for speaker stands and allows for lower bass
response. I chose the F15 because of its
similarity in size to my 3 MK II’s and because
I wanted to try the F15 in a variety of rooms
and placements. I also wanted to see just how
little one can spend these days and still get
music.
The F15’s, at $220/pair, are certainly
inexpensive. Shop around a bit and they become
downright cheap. Say “cheap” to the average
American and the reaction is too often “cheap
and nasty.” Say it to a Brit and the result is
equally likely to be “cheap and cheerful.” The
Celestion F Series, while HT compatible, was
also forged in the demanding crucible of the
ultra-competitive British budget speaker
market - the archetypal sub-$400 per pair,
2-way, 6-inch reflex-loaded woofer,
stand-mount. The High End dogma that only
ultra-expensive gear is even worth considering
is balanced by UK listeners who not only
expect budget speakers to be excellent and
musically compelling, but secretly expect them
to be near-perfect. Both viewpoints are
unrealistic; however, the UK’s pressure cooker
demand has forced the evolution of the budget
speaker into a very high form indeed.
Viewed cosmetically, the F15 looks far more
costly than its grandfather, the UK-built,
non-HT, Celestion 3 Mk II. Its veneered
cabinet looks far more deluxe than the 3’s
vinyl wrap; double 5-way binding posts with
removable links for bi-wiring trump the single
4-way posts of the 3; overall build quality is
far more substantial. The 3 looks like a good
budget speaker built to a price; the F15 looks
quite luxurious, striking because the F15 is
actually $70 cheaper. Score one for the lower
cost of Chinese manufacture.
I ran the F15 with my usual Rogue’s Gallery of
electronics, representing each of the last 5
decades, from the Eico tube preamp/power amp
of the 60’s to the new digital Sonic Impact
T-amp. Six turntables and three CD sources
entered the fray. I played them in 4 different
rooms (2 rooms 8 by 12, one 9.5 by 11, and one
14 by 40) and tried 5 different set-up/speaker
stand-height combinations. I ran the F15’s
through the gauntlet of my Snake Pit of
cables. I even hooked them up to my 20” TV and
watched Ingmar Bergmann’s movie of Mozart’s
The Magic Flute. The differences in these
various set-ups were clearly audible, and more
importantly, the F15’s nailed the individual
signature of each component.
Consistent through all these variations was
the F15’s excellent reproduction of the voice;
lyric intelligibility is first rate. Bass
response was tight and controlled, without a
built-in mid-bass (100 to 125 Hz) rise.
Indeed, when positioning the speaker, care
should be taken not to induce a suck-out in
this crucial region, which so influences
subjective bass drive. This well-damped woofer
alignment leads to easy integration with a
subwoofer, part of Celestion’s plan, one would
logically assume. Whether a slight opacity
from the bass driver was due to its reflex
loading, re-radiation of signals back through
the cone, or to the inherent limitations of a
P-P-treated paper cone I cannot tell.
The presence range did not exacerbate the
typical Pop rip-your-ears-off EQ, being
slightly flattering and allowing violin to
sound like violin. Celestion’s titanium dome
tweeter, capable of producing fine detail and
a delicate sense of the recording venue
acoustic, announces the initial distress if
you over-drive the speaker. It will also
spotlight the weakness of sources,
electronics, cables, and poor recordings. The
difference between LP playback and CD was
immediate and clear.
“Location, location, location.” Small speakers
have an obvious and distinct advantage over
their larger brethren in flexibility of
placement. Indeed, placing them can be a
deviously fine art, ameliorating the
limitations of small speakers – limited power
handling, curtailed bass response - while
maximizing their strengths: vivid and
uncompromised stereo imaging and near-field
detail and transparency. The standard
‘mini-monitor’ set-up: 24-inch tall high-mass
metal stands that position the tweeter at face
height is not the only way to go. I tried
shorter wooden stands (12, 16, and 20 inches
tall) and applied Mapleshade Records’
technique of placing monitor speakers very
near the floor to utilize the floor/rear wall
boundary to reinforce bass response. I also
used the Audio Physic technique of placing the
speaker on the long wall of a rectangular room
and placing them so that there is at 5.5 feet
between the speaker and its side-wall. Finally
I experimented with angling the speaker back a
bit to time-align driver output, and also
inverting the speaker to place the woofer on
top of the tweeter to achieve similar effect.
The first limitation of small speakers –
limited power-handling and thus sound pressure
levels – was easily bypassed. The F15’s 89 dB
sensitivity and 8 0hm load allows it to get
quite loud without a lot of watts, even more
so in smaller rooms. I rarely exceed 85 dB or
so SPL in my listening. It sounds more than
loud enough, and new standards for avoiding
damaging one’s hearing now point to 85 db
against the old 90 dB SPL maximum. I was able
to hit the high 80’s in both my 12 ft. by 18
ft. rooms without problems, even with the 5
watt/channel Sonic Impact digital amp. On the
quiet end of things, every speaker has a
certain volume threshold where it seems to
come alive, and while the F15 did not match
the champions of that criterion, it was making
music in the low 70 dB volume range.
Maximizing bass response was another matter.
Personally, I demand that any speaker get down
to 42 Hz in room to qualify as full-range.
Despite all my sneaky set-up tricks, bass
response met Celestion’s spec, extending to 62
Hz before nose-diving. Response at 40 Hz was
13 dB down from a 1 KHz reference level.
Furthermore, exciting the woofer floor-bounce
cancellation phenomenon by unhappy height
placement could cause a suck-out in the 100
–125 Hz range, leading to a lack of both bass
response and subjective bass drive. The F15’s
HT-design side is hereby revealed. Rather than
trade-off sensitivity or use a larger woofer
or box to extend bass response another
half-octave, Celestion opted for HT standards.
Not enough bass? Add a subwoofer. I can hear
the deafening chorus of “Duh” clearly.
Celestion makes a dedicated and inexpensive
subwoofer, but in my determination to see how
cheap (and cheerful) I could go, I used the
$124 Dayton Loudspeaker Co. powered 10-inch
subwoofer from Parts Express. Having dealt
with satellite/subwoofer set-ups since the
late 70’s (the original Visonik David 50 and
M&K Goliath subwoofers,) set-up was quick and
easy. I placed the F15’s on 24’’ metal stands,
moved them far enough into the 12 by 18 foot
room to optimize their already exquisite
stereo imaging, placed the subwoofer exactly
between them, set the crossover to 80 Hz, and
began smiling like a clam.
Bass response now was rock solid to 30 Hz, and
the F15’s 5¼-inch woofer, freed from most of
its bass demands, danced and swung with a
new-found rhythmic certainty and confidence.
The stereo illusion, already superb due to the
airiness of the F15’s tweeter and its
point-source-approximating cabinet, became as
good as it gets with the low bass information
illuminating the size and subtle detail of the
recording venue. The tweeter’s tendency to
tell you too much news in the 5 KHz region was
less obvious due to it being balanced by the
bottom two octaves.
It was by isolating the speakers from their
stands that the F15’s really came into song. I
tried the Stillpoints, the Aurios PRO’s, and
the Ganymede VCS devices (I did not have the
Townshend 2-D Seismic Sink stands in-house.)
State of the Art isolation produced a greater
difference than type or quality of speaker
stand or speaker cable. The increase in
clarity and resolution was profound; the
slight opacity of the bass/mid driver dropping
below the threshold of perception and the
thorny issue of the titanium tweeter producing
too much energy at 5KHz disappeared. What I
had been assuming as the inherent limitation
of the tweeter was actually being caused by
resonant interference. Since isolation removes
the bass contamination from the environment
and since it also removes the speaker-produced
floor and return mechanism, the F15’s limited
bottom end was more obvious, making a
subwoofer essential. Isolating the subwoofer
too yielded a truly exceptional 3-piece system
that should satisfy all but the most picky.
Since the F15’s and subwoofer can be bought
for less than $300 total, this is indeed a
price breakthrough for high-performance audio.
The F15’s bass/mid driver lags behind the
state-of-the-art Harbeth Radial cone driver
and the lower mass of electrostatics and
ribbons, as well it should. Though far more
controlled, refined and subtle than its
Celestion predecessor the 3 MK II, it doesn’t
quite match that speaker’s inherent exuberance
and magical way of phrasing, rhythmic
certainty, and overall immersion into the
quality of the playing. Care should be taken
that sources, amplifiers, and cables can do
the basics of music well. Garbage in, garbage
out.
So a very high recommendation for the F15 when
used with a subwoofer. $300 is less than what
many audiophiles spend per foot of speaker
cable: in that High End context the system’s
cost is practically free. Allocating funds for
isolation allows the system to be truly cheap
and cheerful, making one wonder what the hell
High End orthodoxy means when it calls $10,000
speakers “budget designs.”
Paul Szabady
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Specifications:
2-way bookshelf loudspeaker.
¾ inch titanium dome tweeter
5¼ inch polypropylene-treated paper woofer.
Bass-reflex loading at top rear of cabinet.
Sensitivity: 89 dB
Frequency Response: 65 to 20,000 Hz +/- 2 dB
Crossover frequency: 2500 Hz.
Dimensions: 12.6” x 7.8” x 10.7” (HxWxD)
Weight: 11 lbs.
Price: $220 per pair.
Address:
Celestion Consumer Division
Eccleston Road
Tovil, Maidstone, Kent
ME15 6QP UKTel: +44 (0) 1622 687442 Fax: +44
(0) 1622 687981
Free Phone: 0800 731 3410
Celestion US:
Website:
www.celestion.com
E-mail:
mailto:info@celestionamerica.com

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