REPRINTED FROM STEREO REVIEW OCTOBER 1996
"If your budget allows spending $2,000 or so a pair...
This new entry from PINNACLE®
can compete comfortably in this select company at half the
The Classic Gold Tower created the kind of natural soundstage and stereo imaging
you'd expect from a top quality columnar speaker costing twice as much. ... skin tingling
deep bass (its useful lower limit appears to be in the 25-27 Hz range)."
Pinnacle® Classic Gold Tower Speaker
JULIAN HIRSCH HIRSCH-HOUCK LABORATORIES
PINNACLE® loudspeakers, which now comprise more than
models, have been a part of the audio scene for some twenty years. From the company's
inception most of its speakers have shared several characteristics, including a compact
size, moderate price, and consistently good sound quality. A significant factor in the
sound of PINNACLE® speakers is the company's patented
Diaduct bass-vent system, which uses
a slanting duct placed diagonally in the cabinet. That permits a longer duct for a given
enclosure size, which enables PINNACLE® speakers to generate deeper or less distorted bass
for a given driver and cabinet size (and price) than would be possible otherwise.
Most PINNACLE® speakers are priced around $200 to $400 a
pair, but the company recently announced a new top-of-the-line floor-standing speaker, the
Classic Gold Tower, as the flagship of its
Audio Cinema line.
The Classic Gold Tower is constructed in the popular format
implied by its name, though it is not as formidable physically as some of the larger tower
speakers we have reviewed in recent months. It is a "2 1/2-way" system, with a
1-inch fluid-cooled aluminum-dome tweeter located near the top of the front panel. Below
the tweeter are two 8-inch cone woofers, one above the other.
The tweeter and the upper woofer form a two-way system with
a first-order crossover (6 dB per octave) at 2.5 kHz. The bottom woofer has a separate
low-pass filter and principally covers frequencies below 150 Hz. Over much of the bass
range, however, both woofers are active, with the acoustic coupling between them further
enhancing the system's bass output.
The internal volume of the cabinet is vented by three
Diaduct tubes whose openings are on the rear of the cabinet. Each tube is 3 inches in
diameter, which is said to give the venting system an effective port diameter of 5 1/4
inches and length of 13 inches. According to the manufacturer, the port system is
principally effective in the lowest three octaves (presumably below 150 Hz), where it
reinforces the direct woofer output.
The Classic Gold Tower is a high efficiency speaker rated
for a 95-dB sound-pressure level (SPL) at 1 meter with a 2.83-volt input, which our
measurements confirmed. It is also rated to handle 150 watts (400 watts peak) and has a
nominal impedance of 8 ohms.
The speakers come with sturdy, solid brass conical mounting
feet, whose use is recommended by the manufacturer. To facilitate positioning and moving
speakers on a carpeted floor, we never use optional spikes or other pointed feet, although
the PINNACLE® feet are not the needle-point variety used on many other speakers.
The rear panel of the speaker cabinet has separate
gold-plated binding posts for the lower woofer, compatible with single or dual banana
plugs, that are normally strapped to the main inputs for the system. This allows the lower
woofer to be driven from a separate amplifier if desired. PINNACLE® suggests that this mode
of operation offers greater flexibility for shaping system response or for obtaining
higher bass levels.
We placed the PINNACLE® Classic Gold Tower speakers
approximately as recommended, about 8 feet apart and 3 feet in front of the wall behind
them (the Diaduct tubes in the rear require at least several inches of clearance from the
rear wall, though the precise distance is not critical).
A close-miked measurement of woofer response, with the
microphone between the two woofers, indicated a maximum output at about 95 Hz, but the
response was within ±6 dB from 40 Hz to 2 kHz. Separate close-miked measurements at each
of the woofers showed that the upper woofer's response was quite similar to the combined
output measured at the front panel between the two drivers. The bottom woofer, on the
other hand, delivered its output largely between 40 and 600 Hz.
Although those figures are not easily translated into
audible terms, they illustrate the separate, synergistic contributions of the two woofers
to the speaker's total bass output. A much more striking demonstration of the Classic Gold
Tower's bass performance came from a measurement of distortion at a drive level of 1.6
volts, which corresponds to a 90-dB SPL at 1 meter. Over the range of 70 Hz to 1 kHz, the
distortion was a virtually constant 0.3 percent, an unusually low figure for a
loudspeaker. As expected, it rose at lower frequencies, where cone excursion increases,
but reached only 3.5 percent at 20 Hz. Although that might not seem impressive compared
with amplifiers and CD players, it is most unusual for a speaker.
The smoothed and averaged room response of the two
speakers, measured 12 feet away on the axis of the left one, was within ±3 dB from 20 Hz
to 2 kHz, dropping off by an additional 7 dB at 20 kHz. Room response includes, in
addition to the inherent response of the speaker, the effects of absorption at
room-boundary surfaces, and since our room is fully carpeted and has an acoustical-tile
ceiling, this is not an unusual measurement.
The horizontal dispersion of the system, measured 12 inches
from the tweeter over an angle of ±45 degrees, was good, with a response variation of
only ±5 dB from 1 to 15 kHz. Above 15 kHz the response fell off more rapidly, dropping to
about -20 dB at 20 kHz.
Quasi-anechoic (MLS) response measurements yielded very
similar results at distances of 1, 2, and 3 meters. With the response plot expanded to
show more detail, two salient characteristics were clear: The overall response was an
excellent ±4.5 dB from 300 Hz (the lower limit of the measurement) to 20 kHz, and this
range included a relatively narrow notch of about 4 dB at 4.6 kHz.'
The notch effect was not audible under any conditions we
could devise, and we can only surmise that it was an artifact of the rather unconventional
crossover system. Disregarding the notch (only a few hundred hertz wide), the response
would be an outstanding ±3 dB from 300 Hz to 20 kHz.
The Classic Gold Tower has a nominal 8-ohm impedance
rating. We measured a minimum impedance of 3.5 ohms at 36 Hz and 4 ohms at II 0 Hz, with
maxima of 15 ohms at 23 Hz, 70 Hz, and I kHz. The manufacturer points out (correctly) that
the system's high efficiency makes its 8-ohm rating valid, since no amplifier likely to be
used with it is going to be stressed even when driving the speakers to high listening
Our listening experience with the Classic Gold Tower was
completely consistent with its measured performance. It created the kind of natural
soundstage and stereo imaging that you'd expect from a top-quality columnar speaker
costing twice a much. Even the skin-tingling deep bass it delivered had the authority of a
much more expensive speaker (its useful lower limit appears to be in the 25 to 27-Hz
One of the most impressive things about the Classic Gold
Tower is its economy. Unquestionably, there are a number of excellent speakers to choose
from if your budget allows spending $2,000 or so a pair. This new entry from
compete comfortably in that select company at half the price. And you won't have to invest
in a high-powered (and high-priced) amplifier to do justice to your system although the
Classic Gold Tower can play at house-shaking levels when appropriate and still