Vero Research manufactures loud speakers for the home market and studio monitors
for recording studios under the brand name Soundwave, and has been in business
since 1987. The company's founder, James Gala (now its technical director),
conceived and now holds a patent on a unique series of loudspeakers whose cabinets
are "V"-shaped, with the point (apex) of the "V" facing
the listener.
The Point Source 3.0 closely follows this style by mounting two 8-inch woofer/midrange drivers on either side of the narrow "V," with one mounted higher than the other to prevent interference between the magnets. A small, forward-facing tweeter is mounted at the point of the "V," vertically centered between the larger drivers. An additional tweeter is mounted on the top of the cabinet, facing upward.
The Point Source 3.0 is second from the top of a series of four systems which range in price from $1,490 per pair, for the smaller three driver Point Source 1.0, to $3,490 per pair for the largest Point Source 4.0 six-driver system.
Why mount the drivers in the "V" configuration? According to Gala, this mounting arrangement packs the drivers in the closest possible space, and thus provides a coincident and coherent point source that provides optimum, even coverage in the front hemisphere of the system. The included angle of the "V" is a narrow 64°, which means that the effective width of the two bass/midrange drivers is only slightly wider than one unit. Gala describes this arrangement as a new variation of the D'Appolito configuration (a vertical array formed by a tweeter flanked by two larger drivers), which provides symmetrical, even vertical coverage. A conventional D'Appolito configuration using 8-inch drivers might, however, have too little vertical coverage; Gala's variation avoids this problem coverage because the two larger drivers are effectively mounted closer together vertically.
Gala states that the "V" design offers improvements in stereo imaging and tonal accuracy by reducing high-frequency beaming and by minimizing reradiated sound from adjacent cabinet surfaces. Any reradiation that does occur is directed off to the side and away from the listener, and thus is less audible.
Gala further states that the "V" design allows the enclosure and drivers to approximate a true point source, yet also allows the cabinet to be large enough to house drivers of sufficient acoustic output to re produce music at live performance levels.
The Point Source systems were designed to provide even coverage in the full front hemisphere (180°), and not just in a narrow angle directed toward the listener. This is a direct result of the extreme narrowness of the front of the "V"-shaped enclosure. An additional tweeter is used, to improve power response at high frequencies. To minimize rear-wall bounce, this tweeter is top-mounted and aimed straight up at the ceiling. According to Gala, the top tweeter improves high-frequency coverage, especially for listeners who are standing close to the system. In summary, Gala says that his goal with the Point Source systems is to "have the seamless sound of the highest quality two-way designs, the acoustic output and power handling of three-way designs, and a radiation pattern superior to both."
The enclosure of the Point Source 3.0 is completely filled with acoustic foam and has a rear-mounted circular port. This speaker can be converted back and forth from a closed-box to a damped vented-box system, by removing or inserting a sup plied rubber plug. The cabinet of the Point Source is well braced, while the unique shape minimizes internal standing waves. All panels are 3/4-inch medium-density fiberboard. Construction is excellent, and tolerances are tight. Except for the top, the whole cabinet is covered with black grille cloth. The grille cloth can be easily rolled down the outside of the cabinet in order to reveal the drivers; this is done by removing the top plate (which is attached by pegs and plastic hook-and-loop fasteners), un-loosening a draw string, and then pulling down the cloth. Both spikes and rubber feet are provided for attachment to the bottom of the cabinet.
The 8-inch bass/midrange drivers of the Point Source have an extremely overhung voice-coil, 21 mm (0.83 inch) long, for large excursion. The small-diameter front tweeter has a vented high-energy neodymium magnet with a composite fabric dome. The vent leads to a sealed felt-filled air chamber that lowers the fundamental resonance of the tweeter to below its operating range. The top tweeter is of similar design but uses a ferrite magnet.
The crossover is a simple, straightforward design and includes a first-order low-pass filter with impedance compensation for the woofer, and a second-order high pass on the tweeters. A three-position, heavy-duty rotary switch on the rear panel provides ±1.5 dB of tweeter-level adjustment. The top tweeter is driven through a series resistor to slightly attenuate its level. The crossover contains nine components (five resistors, two inductors, and two capacitors). The parts are mounted on a heavy p.c. board attached to the rear input connection panel. High-quality Solen capacitors are used, as are air-core inductors. The heavy-gauge connecting wire is attached to the p.c. board with an industrial-grade, automotive-style multi-pin connector. The system can be bi-wired and includes two large double-banana gold-plated connectors, with straps, on the rear panel.
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SPECS:
Type: Two-way, floor-standing system with point-source drive unit geometry and convertible, vented/sealed, enclosure.
Drivers: Two 8-in. cone woofers, one 1-in. neodymium-magnet fabric-dome tweeter, and one top-mounted 1-in. ferrite-magnet fabric-dome tweeter.
Frequency Response: 34 Hz to 20 kHz, ±3 dB.
Sensitivity: 90 dB at 1 meter with 2.83 V rms input.
Crossover Frequency: 2.2 kHz.
Impedance: 5 ohms nominal, 4.7 ohms minimum.
Recommended Amplifier Power: 50 to 300 watts per channel.
Dimensions: 42 in. H x 12 in. W x 17 in. D (106.7 cm x 30.5 cm x 43.2 cm).
Weight: 60 lbs. (27.3 kg) each.
Price: $2,490 per pair; available with high-gloss black acrylic top panel and black grille cloth or with white top and white grille cloth.
Company Address: c/o Vero Research, 1150 University Ave., Rochester, N.Y. 14607.
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Measurements
Fig. 1--One-meter, on-axis frequency response.
Fig. 2--On-axis phase response and group delay.
Fig. 3--Energy/time response.
Fig. 4--Horizontal off-axis frequency responses.
Fig. 5--Vertical off-axis frequency responses.
Fig. 6--Impedance.
Fig. 7--Complex impedance.
Fig. 8--Three-meter room response.
The anechoic frequency responses of the Point Source 3.0, with the port open and closed, are shown in Fig. 1. Measurements were taken at a distance of 2 meters on the front tweeter's axis, with an input of 5.66 V rms. The curves are referenced back to 1 meter and are 10th-octave smoothed. The response shelves downward above about 1 kHz, with the level dropping about 4 to 5 dB. Individually considered, the responses above and below 1 kHz are each quite flat and well behaved. Even with the shelving, the overall curve fits a fairly tight, 7-dB window (approximately ±3.5 dB referenced to 1 kHz), with a quite respectable bandwidth of 45 Hz to 20 kHz.
With the port open, the response exhibits a slight increase in output, averaging about 0.75 dB, over a broad range from 32 to 180 Hz. The grille cloth did not affect the response much at all, causing only slight, ±1 dB variations in narrow frequency ranges. All further tests were done with the grille installed. Averaged over the range from 250 Hz to 4 kHz, the sensitivity of the Point Source 3.0 measured 87.0 dB, about 3 dB below Vero's 90-dB rating. Above 1 kHz, sensitivity was even lower, averaging about 84.5 dB. The right and left units were matched within a close ±0.8 dB. The three-position sensitivity switch caused about a ±1.5 dB change above 3 kHz (response not shown). The phase and group-delay responses of the Point Source 3.0, referenced to the tweeter's arrival time, are shown in Fig. 2. The phase rotates about 235° between 1 and 3 kHz, quite a narrow range of frequencies. This rapid rotation is due primarily to the relatively large physical offset between the tweeter and bass/midrange drivers, and to the crossover. (The dust caps of these drivers are about 5 inches be hind the mounting plane of the tweeter.) The group-delay curve indicates that the midrange lags the tweeter by a significant 0.5 to 0.75 mS. The large dip in the group de ay, at about 160 Hz, corresponds to he effects of a minimum-phase dip in the frequency response at the same frequency. If frequency response was equalized flat in this range, the group-delay dip would disappear.
Figure 3 shows the axial energy/time response. The test parameters accentuate the response from 1 to 10 kHz, which includes the crossover region. The main arrival, at 3 mS, is quite compact but is followed by several relatively high-level narrow peaks, only 13 to 18 dB down, which extend out to about 1.5 mS behind the main peak.
Figure 4 shows the horizontal "3-D" off-axis responses; the bold curve at the rear of the graph is the on-axis response. Because the on-axis response ripples mostly carry over into the off-axis curves, the horizontal coverage is quite good. However, some narrowing of coverage is evident in the range from 1.25 to 2 kHz (not clearly shown in the graph), due to the laterally separated bass/midrange drivers. This narrowing causes an 8-dB dip, two-thirds of an octave wide, in the response at 40° off the horizontal axis. In the primary listening window, ±20° of the axis, the narrowing is not significant.
Fig. 9-Harmonic distortion for E1 (41.2 Hz).
Fig. 10-IM distortion for A4 (440 Hz) and E1 (41.2 Hz).
Fig. 11-Maximum peak input power and sound output.
The vertical "3-D" off-axis curves of the Point Source 3.0 are shown in Fig. 5. The bold curve in the center of the graph (front to rear) is on-axis response. Clearly seen in the set of curves is the elevated response below 1 kHz, which carries over to all the off-axis curves in the form of interference dips. In the primary vertical listening window, ±20° of the axis, the response is quite uniform. The output of the top-mounted tweeter is clearly shown in the elevated high-frequency response, which rolls off from on-axis to 45° above axis but begins rising again as the angle shifts toward +90°.
In general, although the horizontal and vertical off-axis responses of the Point Source 3.0 in the primary listening window are very uniform, responses farther off axis in both planes exhibit significant dips be tween 1 and 2 kHz. This indicates that the power response is attenuated in this range.
Figure 6 shows the impedance, from 5 Hz to 20 kHz, with the port open and with the port closed. The impedance does not drop below a safe 5 ohms at any frequency. The maximum impedance, 17.4 ohms, occurs at about 57 Hz, the closed-box resonance frequency with the port closed. The low impedance between 20 and 35 Hz with the port open indicates a broad vented-box tuning. The impedance has a max/min variation of about 3.5 to 1 (17.4 divided by 5). Cable series resistance should be limited to a maximum angle o about 0.080 ohm to keep cable-drop effects from causing response peaks and dips greater than 0.1 dB. For a typical run of about 10 feet, cable of 16 gauge or larger should be used.
Figure 7 shows the complex impedance of the Point Source 3.0, from 5 Hz to 30 kHz, with the port closed. Most activity takes place at the closed-box resonance of 60 Hz in the bass range, and at the 1-kHz impedance peak just below crossover. The impedance phase (not shown) reached a maximum angle of +31° (inductive) at 45 Hz and a minimum of -36° (capacitive) at 1.6 kHz. A single Point Source 3.0 per channel will be no problem for any amplifier.
A high-level sine-wave sweep revealed a quite rigid cabinet with no significant vibrations. The 8-inch woofers have a healthy maxi mum travel capability of about 0.65 inch, peak to peak. Higher 100 excursion generated only high third-harmonic distortion but with no bad sounds. No dynamic offset was evident at any input level or frequency.
With the port open, the excursion of the woofers was reduced somewhat over a broad range, 20 to 70 Hz. No definite null was evident. The maximum excursion reduction from opening the port was about 15% at 40 Hz. When open, the port generated significant wind noises at high input power levels, from air turbulence.
Removing the rear connection panel revealed that the bottom fourth of the cabinet is dead air space. A full partition exists about 12 inches above the bottom.
The 3-meter room response of the Point Source 3.0, with both raw and sixth-octave smoothed data, is shown in Fig. 8. The speaker was in the right-hand stereo position, aimed at the listening position, with the test microphone placed at ear height (36 inches) at the listener's position on the sofa. The system was driven with a swept sine-wave signal of 2.83 V rms, corresponding to 1.6 watts into the rated 5-ohm load. The direct sound and 13 mS of the room's reverberation are included.
Overall, the averaged curve does not exhibit any large deviations in response over the whole measured range. Notably absent are any major dips in the floor-bounce region, from 200 to 700 Hz. Above 1 kHz, the overall curve exhibits a downward tilt of about 4.5 dB per decade, or about 1.3 dB per octave. The whole curve fits within a fairly tight, 10-dB window.
Figure 9 shows the E1 (41.2-Hz) bass harmonic distortion spectrum of the Point Source with input power ranging from 0.1 to 100 watts (22.4 V rms into the rated 5-ohm load). The second harmonic reaches only 3.8%, while the third reaches a moderate 11.8% at full power. Higher harmonics are 1.1% and lower. With a 100-watt in put, the system reached a quite usable 98 dB SPL at 1 meter, at 41.2 Hz.
The A2 (110-Hz) and A4 (440-Hz) harmonic distortion data is not shown be cause it reached only low values of 1.1% second harmonic at 110 Hz, and 0.6% second at 440 Hz, at full power. Higher harmonics, at both frequencies, were below the noise floor of my analyzer. The Point Source 3.0 sounded quite clean at all three test frequencies at full power. It could actually handle 30 V rms at 20 Hz and above (20 V rms at 16 Hz) in the woofers' range, with the port open or closed, without making any bad sounds or being harmed! This is the second highest bass and sub-bass power handling that I have measured on any system.
Figure 10 displays the IM created by tones of 440 Hz (A4) and 41.2 Hz (E1) of equal power, covering the range from 0.1 to 100 watts. The IM distortion reaches only a moderate 9.1% at 100 watts. This is a relatively low measurement for a two-way system.
The short-term peak power input and output capabilities, as a function of frequency (measured using a 6.5-cycle, third-octave bandwidth tone burst), are shown in Fig. 11. The peak input power was calculated by assuming that the measured peak voltage was applied across the speaker's rated 5-ohm impedance.
The peak power handling starts out at a very strong 116 watts at 20 Hz, rises quickly to 1.5 kW at 100 Hz, and reaches a plateau of 10 kW (±223 V, peak, into the 5 ohm load) above 300 Hz! (Wow! Another 10,000-watt system! The Soundwave essentially ties the other all-time winner of the peak-power sweepstakes, the PSB Stratus Gold system reviewed in the November 1991 issue.) No problems were evident at any frequency.
With room gain, the maximum peak output SPL of the system starts at a very strong 99 dB at 20 Hz, and rises rapidly into the range from 120 to 130 dB above about 100 Hz. With an amplifier having sufficient peak-power capability, the Point Source will have no problems re-creating the peak SPLs of live instruments in a typical listening room. In the bass range, 110 dB is attained at 40 Hz and 120 dB is reached at 75 Hz. This places the Point Source in the top third of all the systems I have tested for peak bass output capability.
Use and Listening Tests
The Point Source 3.0s have a very distinctive, angular look. When set up for listening, the narrow, pointed front baffle is like a large arrowhead pointed straight in your direction. There is no doubt where you need to sit-that is, until you turn the speakers on and do some listening, either seated or while walking around, and discover that the coverage is quite broad both vertically and horizontally. The Sound-waves still sound good even if you walk be tween and around them; there is no loss of highs. The top-mounted tweeter really pays off here. This tweeter also adds a certain amount of sheen and airiness to high frequencies, especially percussion such as hi hat cymbals, even when you listen sitting down and on axis.
Listening equipment included my usual Onkyo and Rotel CD players, Krell KRC preamp and KSA250 power amp, Straight Wire Maestro cabling, and the B & W 801 Matrix Series 3 speakers. Listening was primarily done with normal, not bi-wired, connections. All listening was done with the grille cloth on.
Vero Research suggests that the Point Source systems be placed 0.5 meter or more from the rear wall and at least 1 meter from the side walls of the listening room. I placed the systems in my customary locations, which spaced them about 8 feet apart and well away from the side and rear walls. Listening was done from my couch, 10 feet away. The systems were canted in so that I was on axis when seated in the center of the couch.
The instruction manual for the Point Source 3.0 is quite brief, a single 8 1/2 x 11-inch page, folded. Areas covered include electrical connections, loudspeaker placement, use and listening, care and cleaning, and service.
First listening was done with the sampler tracks on The Sheffield /XLO Test & Burn in CD (Sheffield Lab 10041-2-T). The Point Sources acquitted themselves very well, particularly in the previously mentioned high-frequency area, but also in bass, where the reproduction of the kick drum on the sampler's Michael Ruff and Pat Coil pop tracks was quite clean, dynamic, and satisfying.
The Point Sources were essentially equal in sensitivity to my reference B & W systems. The tonal balance was different, however, with the Soundwaves tilted down somewhat in treble and up a bit in bass.
Their subterranean bass response was not the equal of the B & Ws', but the rest of the bass was very close in dynamics, cleanliness, and loudness capability. Played at high levels on pop material, such as Gene sis' We Can't Dance (Atlantic 7 82344-2), and cleanly recorded country, such as Joe Diffie's Third Rock from the Sun (Epic EK 64357), the Point Source loudspeakers were very involving and dynamic. They produced impressive levels of tight, dance able low end.
The low-end capability and bass power handling of the Point Source 3.0s were up there with the best of the systems I have listened to. Very demanding material, such as the bass drum on Winds of War and Peace (Wilson Audio WCD-8823) and the pedal notes on Jean Guillou's organ version of Pictures at an Exhibition (Dorian Recordings DOR-90117), were handled very cleanly and without a whimper at quite high playback levels. As I said, the very low bass output did not equal that of the B & Ws, but the Point Sources did produce very satisfying levels of clean bass.
With period, a cappella liturgical music on Psalmi et Cantica (Sony Vivarte SK 53 977), the Point Source 3.0 speakers exhibited a quite smooth vocal sound, with no exaggerated sibilance, coupled with excellent imaging and reproduction of hall reverberation.
On the pink-noise stand-up/sit-down test, the Point Source 3.0s did exhibit significant midrange tonal changes. Tonal changes were also evident when I moved back and forth in front of the speakers. The coverage was very broad, however, with no lack of highs, thanks to the top-mounted tweeter. The Soundwave's spectral balance on pink noise was slightly depressed in highs and accentuated in lows, as com pared to the B & W's. Some tonality was also evident in the noise, which indicates a lack of smoothness. On third-octave band limited pink noise, the 3.0s generated some 25-Hz low-bass output, somewhat more usable output at 31.5 Hz, and very good output at 40 Hz and above. Port wind noise was noticeable from 20 to 40 Hz.
On Prokofiev's Piano Concertos Nos. 1, 3, and 5 (Sony Classical SK 52483), the Point Source 3.0s did very well reproducing the dynamics and attack of the piano while demonstrating very good soundstaging. They were somewhat more distant sounding than the B & Ws, however. Female classical vocals were reproduced quite cleanly and with clarity.
On balance, the Point Source 3.0's favor able attributes--such as bass response, imaging, high-frequency coverage, and dynamics-far outweigh such unfavorable ones as a somewhat uneven vertical and horizontal coverage and slightly tilted-down response. At $2,490 per pair, the Point Source has some stiff competition. Do give these speakers serious consideration, however, particularly if you like their very distinctive, angular looks and many positive characteristics.
-D. B. Keele, Jr.
(Source: Audio magazine, Jan. 1995)
Also see:
Snell Type B Speaker (Sept. 1992)
Vandersteen 2Ci Speaker (Equip. Profile, Jun. 1992)
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