Advent Prodigy Speaker System Review

The Advent Prodigy Tower, a compact, floor-standing two-way speaker system, measures 28-1/2 inches tall, 10-1/2 inches wide, and 8-7/8 inches deep and weighs 25-1/4 pounds. Although its proportions probably justify the “Tower” name, it could be described more accurately as a minitower, for it will not dominate even the smallest room.

The cabinet, which appears to be made of 1/2-inch-thick fiberboard, is painted flat black on four sides. The top is covered by a solid piece of oiled pecan wood, and there’s a matching trim plate on the bottom of the front panel. With the black grille cloth in place, the speaker presents an all-black exterior except for the accents of light-colored wood. The spring-loaded input connectors, recessed into the rear of the speaker, accept the stripped ends of speaker wires.

The 8-inch, long-excursion woofer, which operates in a sealed enclosure, is located in the middle of the front panel, with the driver’s center about 16 inches from the floor. At 3,000 Hz there is a crossover to a 3/4-inch, soft-dome tweeter (cooled and damped by ferrofluid) located near the top of the panel. The nominal system impedance is 6 ohms, with a minimum of 4 ohms. The rated sensitivity is 89 dB sound-pressure level (SPL) at 1 meter with a 2.8-volt input, and the speaker is recommended for use with amplifiers capable of delivering up to 75 watts continuous or 300 watts peak.

Advent gives the frequency response of the Prodigy Tower as 45 to 23,000 Hz ±3 dB, with a useful lower limit of 37 Hz (where its output is — 8 dB). The tweeter’s output variation (dispersion) over a 30-degree angle, either vertical or horizontal, is rated as ± 1 dB. The system’s harmonic distortion with a 1-watt input level is rated as less than 0.8 percent above 80 Hz. Price: $350 a pair.

Lab Tests

Advent encourages experimentation in the placement of these speakers, although the Prodigy Towers are designed to be placed on the floor about 1 to 6 inches from the wall. According to the instruction sheet, this placement puts the system close to the ear level of a seated listener, for optimum midrange and treble response, and also provides the flattest low-frequency response.

Since a tweeter only 24 inches from the floor would be at ear level only for listeners sitting on the floor (not our preferred location), we first installed the speakers on 7-inch stands a few inches from the wall. Later we placed them directly on the floor about 18 inches from the wall. The audible differences were quite minor, and we concluded that the speakers are relatively insensitive to placement.

The averaged room response of the left and right speakers was strikingly free from large peaks or dips. In fact, the raw (unsmoothed) room curve was flat within ± 5 dB from 50 to 20,000 Hz, which is quite unusual in our experience. The close-miked woofer response had a broad maximum at 80 Hz, falling at 12 dB per octave below 60 Hz and gradually sloping off by about 6 dB per octave from 80 to 2,000 Hz. The woofer response cut off sharply above 2,000 Hz, but the absence of a significant response hole in the crossover region suggests that the effective crossover frequency may be nearer to 2,000 than to 3,000 Hz.

When the woofer curve was spliced to the room curve, the composite frequency response (relative to the 1,000-Hz level) was +4,-1 dB from 140 to 16,000 Hz. From 43 to 20,000 Hz the variation was +6, — 1 dB. The minimum system impedance was 4.2 ohms in the 100- to 200-hz range and at 20 Hz. The bass resonance was at the rated frequency of 60 Hz, where the impedance reached its maximum of 20 ohms, and there was a broad impedance peak to 17 ohms at 2,000 Hz (additional evidence that this was the true crossover frequency).

The measured sensitivity was 90 dB, slightly higher than the rated 89 dB. When we drove the speaker with 2.83 volts (equivalent to a 90-dB SPL), the woofer distortion was under 0.8 percent from 100 to 60 Hz, easily surpassing the manufacturer’s bass-distortion rating. The distortion climbed gradually at lower frequencies, but only to 4.3 percent at 40 Hz, and below that the output was less than our measurement threshold. We also measured the distortion from 20 to 2,000 Hz using our highly sensitive Audio Precision test system. Up to 100 Hz the readings matched those of our point-by-point measurement, although we were also able to make a measurement at 20 Hz, where the distortion reading was only 5 percent. After reaching a maximum of 0.9 percent at 200 Hz, the distortion decreased steadily to 0.3 percent at 2,000 Hz.

Our quasi-anechoic FFT measurements of the Prodigy Tower generally confirmed the characteristics revealed in our other tests. A crossover dip appeared between 2,000 and 3,000 Hz, putting the actual crossover frequency somewhat in doubt again, although this figure is of little importance to a user. These tests revealed the excellent dispersion of the system’s tweeter: The maximum level change between the on-axis and 45-degree off-axis responses was about 5 dB over the tweeter range up to about 13,000 Hz. Since we operate in a “live” room environment, more precise measurements are difficult to make. In any case, the dispersion of the Advent Prodigy Tower’s tweeter was better than that of most other speakers we have tested.

The Advent system also had excellent phase linearity in its tweeter range, yielding a group-delay variation of about 0.1 millisecond overall from about 4,000 to 20,000 Hz. Pulse power tests indicated an excellent power-handling ability. The woofer began to rattle with a 100-Hz input of 1,150 watts into its 4.8-ohm impedance. At 1,000 and 10,000 Hz, our amplifier clipped before the speaker output distorted, with an input of about 675 watts into respective impedances of 9.8 and 5.8 ohms.

Comments

Judging from their measured performance, the Advent Prodigy Tower speakers are among the better systems available in their modest price range. Happily, they sounded every bit as good as they measured. From the start, their sound was smooth and uncolored, with no noticeable emphasis or deficiency in any portion of the audible spectrum. Further listening revealed that their bass reproduction was more extended and cleaner than in many, if not most, speakers we have heard that are comparable in size or price.

It is difficult to describe or evaluate the sound of speakers heard in isolation; this is best done in careful comparisons with the sound of more familiar models. In this case, we were fortunate in having available a pair of speakers that are not too different in size from the Advents but sell for several times their price. The comparison system sounded superb, with an exceptionally open sound stage. We could not have expected the Prodigy Tower to equal or surpass this “reference” system (not our regular reference, incidentally), but we were surprised to discover what a minute difference there was between the two. Above the mid-bass, the two sounded (and measured) almost identical in their octave-to-octave balance. The Advent was clearly superior in the low bass. The only respect in which the reference system clearly outperformed the Advent System (and only by a moderate amount) was in the breadth, height, and depth of its reproduced sound stage.

Considering the great price difference between these two speakers, and the subtlety of the sonic differences between them, the Advent Prodigy Tower is obviously an outstanding value. You won’t find many $350-a-pair speaker systems with its combination of compact size, smoothness, wide dispersion, extended bass and treble response, high efficiency, high power-handling ability, and low bass distortion. Although calling a speaker of its size and proportions a “tower” might be considered hyperbole, the “prodigy” part of its name is not hard to justify.

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