Pinnacle Classic Gold Tower Floor standing speakers
Pinnacle loudspeakers, which now comprise more than a dozen 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 "2.5-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 5.5 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 110 Hz, with maxima of 15 ohms at 23 Hz, 70 Hz, and 1 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 levels.
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 as 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 range).
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 Pinnacle can 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 sound musical.
