What costs only $199, weighs 24 pounds, and sounds pretty darn good? Answer:
A pair of Dana Audio Model 1’s. The Model 1 is a straightforward two-way design
using a small metal-dome tweeter and a 6 1/2-inch woofer mounted in a 0.4-cubic-foot
(11.3-liter) sealed enclosure. Dana Audio sells the Model is only by mail order
through its store in Knoxville, Tennessee (walk-ins are allowed too). Dana
Audio's whole speaker line consists of just two products, the full-range Model
1 and the Sub-1, a tubular-style ported subwoofer that sells for only $295.
Although only the Model 1 system is reviewed here, I was sent a Sub-1, which
I used in some of the listening tests. Early this year, several new speakers
will be added to Dana Audio's line.
Dana Audio was founded in 1989 by John and Dana Fish to market the Model 1. In 1992, they contracted with Prof. James Carroll, founder and owner of Applied Physics Labs (a full-line speaker manufacturer that has been around since 1972), to design an inexpensive subwoofer. This collaboration resulted in the Sub-1 being added to the line in September 1992.
In May 1994, the company was purchased by Carroll and is operated completely separately from APL. (Carroll is a physics and mathematics teacher at Roane State Community College in Harriman, Tennessee.) The woofer of the Model 1 is a high-excursion design sourced from KSC of California and manufactured in Mexico, while the tweeter is a titanium-dome version of an off-the-shelf Audax unit, made in France. The Model l's crossover is a first-order electrical design using driver-impedance compensation on both the woofer and the tweeter. The impedance compensation essentially flattens the system's impedance throughout the whole audio range, except for the system's closed-box bass resonance below 100 Hz. The crossover contains eight components (three resistors, two inductors, and three capacitors). All air-core inductors are used, with good-quality capacitors. The parts are wired point to point and hot-melted to a board that is mounted to the bottom of the enclosure. All connections are soldered. A pair of five-way double-banana jacks mounted on the rear of the cabinet accomplish the input connections; bi-wiring is not supported. Large wire, up to 5 mm (0.2 inch) in diameter, can be accommodated.
The cabinet of the Model 1 is quite rigid and constructed with 5/8-inch medium-density particleboard. No bracing is used in the cabinet, which is small enough to be rigid without it. The cabinet is available only in a textured black laminate finish.
The grille, which is composed of black cloth covering a 1/2-inch-thick fiberboard frame, attaches to the front panel with four plastic projections that mate with recesses in the front panel. The drivers are surface-mounted on the front panel of the cabinet. Speaker stands for the Model is are available separately from Dana Audio.
The bottom-ported subwoofer companion to the Model 1, the Sub-1, contains a high-excursion 8-inch driver mounted on the top of a tube that is 38 inches high and 10 inches in diameter. The subwoofer is passive but requires that the power amplifier output connect directly to the woofer, with the Model 1 satellites in turn being driven from output connections on the woofer. The subwoofer contains 80-Hz low-pass filtering for itself and high-pass filtering and a three-position level adjustment for the satellites. The vented-box tuning of the Sub-1 is a low 25 Hz, which qualifies it as a true subwoofer.
Measurements
The 1-meter anechoic frequency response of the Model 1 is shown in Fig. 1, along with the effect of the grille. Measurements were taken at 1 meter on box axis (which is very close to the woofer axis, the manufacturer's design point), with a signal voltage of 2.83 V rms (1 watt into the rated 8 ohms). The curves are 10th-octave smoothed. The response below 400 Hz was derived from ground-plane measurements.
The overall curve, with grille off, fits a tight 5-dB window (+1,-4 dB, referenced to 1 kHz) from 70 Hz to 20 kHz. Major features include a moderate plateau between 400 Hz and 1 kHz and a slight downward trend above 1 kHz, with some roughness evidenced by dips at 5 and 12 kHz. Below 80 Hz, the response rolls off at the 12-dB/octave rate exhibited by all closed-box systems.
The grille affects the response only above 2 kHz, where response deviations of only +1,-1.5 dB are evidenced in narrow bands. The system can be critically listened to with the grille on. Averaged from 250 Hz to 4 kHz, the sensitivity of the Model 1 measures 85.5 dB, about 1.5 dB below Dana's 87-dB rating. The right and left units were matched within a close ±1 dB above 1.6 kHz but were not as close between 900 Hz and 1.6 kHz, where the response of one unit was about 1.5 to 2 dB higher than its mate's.
The phase and group-delay responses of the Model 1, referenced to the tweeter's arrival time, are shown in Fig. 2. The phase rotates only an additional 206° between 1 and 10 kHz. The group-delay curve above 800 Hz indicates that the midrange lags the tweeter by an insignificant 0.1 to 0.15 mS.
The large dip in the group delay at about 190 Hz corresponds to the effects of a minimum-phase dip in the frequency response in the same frequency range. If equalized flat in this range, this group-delay dip would disappear.
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SPECS
Type: Two-way, acoustic-suspension, bookshelf system.
Drivers: 6 1/2-in. cone woofer and 3/4-in. titanium-dome tweeter.
Frequency Response: 63 Hz to 20 kHz, ±3 dB.
Sensitivity: 87 dB at 1 meter, 2.83 V rms applied.
Crossover Frequency: 3.15 kHz.
Impedance: 8 ohms, nominal.
Power Handling: 60 watts continuous, 100 watts peak.
Dimensions: 14 3/4 in. H x 8 3/4 in. W x 7 1/2 in. D (37.5 cm x 22.2 cm x 19.1 cm).
Weight: 12 lbs. (5.5 kg) each.
Price: $199 per pair.
Company Address: 8807 Kingston Pike, Knoxville, Tenn. 37923.
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Fig. 1-One-meter, on-axis frequency response.
Fig. 2-On-axis phase response and group delay.
Fig. 3-Ene-gy/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 Model l's axial energy/time response is shown in Fig. 3. The test parameters emphasize the response from 1 to 10 kHz, which includes the crossover region. The main arrival, at 3 mS, is quite slender but widens significantly at levels 15 dB below the peak. Additional peaks are noted, trailing the main peak some 21 to 23 dB down.
Figure 4 shows the horizontal "3-D" off-axis responses of the Model 1; the bold curve at the rear of the graph is the on-axis response. Because the on-axis response ripples are carried over into the off-axis curves, the horizontal coverage is very good. The horizontal high-frequency coverage is particularly even because of the small size of the tweeter. Response is down only about 3 dB at 12 kHz at 45° off axis.
The vertical "3-D" off-axis curves of the Model 1 are shown in Fig. 5. The bold curve in the center of the graph (front to rear) is on axis. Excellent high-frequency coverage is evident above 5 kHz. Some narrowing of response is apparent in the crossover range of 2.5 to 6 kHz. The 0° and ±5° curves are very uniform, but for greater angles the response is depressed in the crossover region (not clearly shown in the graph). A broadening of response in the region from 1.5 to 2 kHz is evident from the off-axes ridge at 1.8 kHz.
Figure 6 shows the Model l's impedance from 20 Hz to 20 kHz.
Other than an impedance maximum of 26.5 ohms at the closed-box resonance frequency of 78 Hz, the impedance is very well behaved.
A minimum impedance of 6.3 ohms occurs at 4 kHz. Above 130 Hz, the impedance varies only from a minimum of 6.3 ohms to a maxi mum of 8.5 ohms! Over the whole audible range, the impedance has a max/min variation of about 4.2 to 1 (26.5 divided by 6.3). Cable series resistance should be limited to a maximum of about 0.10 ohm (100 milliohms) 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. However, if only the response above 130 Hz is important (which includes the important midrange), the impedance has a max/min variation of only 1.35 to 1 (8.5 divided by 6.3). Cable series resistance in this case can be allowed to rise to the quite high level of 0.30 ohm (300 milliohms) for the same 0.1-dB response tolerance.
In this situation, very small cable, in the range of 22 to 24 gauge, could be used! Figure 7 shows the complex impedance of the Model 1, from 5 Hz to 30 kHz. Most activity takes place in the bass range, at the closed-box resonance at 78 Hz, where a single circular loop is evident. A much smaller loop is evident at about 750 Hz. Above 113 Hz, all the complex variation of impedance occurs in a very small window ranging from 6.3 to 8.4 ohms on the real axis, and -j5.6 to +j1.4 ohms on the imaginary axis! The impedance phase (not shown) reached a maximum of +23° at 60 Hz and a minimum of -44° at 100 Hz. Even if used in parallel, Model is should be no problem for any power amplifier or receiver.
The cabinet did not exhibit any significant wall vibrations when the system was driven by a high-level sine-wave sweep.
Some activity of the front and sides was evident at and near 350 Hz but did not cause any consequential problems.
The 6 1/2-inch woofer had a maximum excursion capability of about 0.35 inch, peak to peak. Higher input levels resulted in increased third-harmonic distortion but with no bad sounds. The system could handle up to 20 V rms at any frequency in the bass range without harm. There was no dynamic offset evident at any input level or frequency.
Fig. 9-Harmonic distortion for B1 (61.7 Hz).
Fig. 10-Harmonic distortion for A2 (110 Hz).
Fig. 11-Harmonic distortion for A4 (440 Hz).
Fig. 12-IM distortion for A4 (440 Hz) and B1 (61.7 Hz).
Fig. 13-Maximum peak input power and sound output.
The 3-meter room response of the Mod el 1, with both raw and sixth-octave smoothed data, is shown in Fig. 8. The speaker was in the right-hand stereo position, sitting on a 28-inch stand that raised the middle of the box to about 36 inches.
The system was aimed at the listening position, with the test microphone placed at ear height (36 inches), at the listener's position on the sofa. The speaker was driven with a swept sine-wave signal of 2.83 V rms (corresponding to 1 watt into the rated 8-ohm load). The direct sound and 13 mS of the room's reverberation are included.
Excluding a dip at 330 Hz, the averaged curve fits within a fairly tight, 9-dB window. No major anomalies are evident in the averaged curve except for general roughness over the whole range and a raised response between 500 Hz and 1 kHz.
Figure 9 shows the B1 (61.7-Hz) bass harmonic distortion spectrum of the Mod el 1 at input power levels from 0.05 to 50 watts (20 V rms into the rated 8-ohm load). The second harmonic reached 8.1%, while the third reached a high 24% at full power. Higher harmonics were 2% fourth, 3.6% fifth, and 1.4% sixth. Uncharacteristically, both the third and fifth harmonics started out at fairly high values and maintained approximately the same distortion values over a wide power range of about 0.05 to 5 watts. At this frequency, the sys tem did not sound very clean at any power level. With 50 watts in put at 61.7 Hz (B1), the system reaches 96 dB SPL at 1 meter.
The higher frequency, B1, note was chosen instead of the usual lower E1 (41.2 Hz), due to the small driver size of the Model 1 and its reduced low-frequency capability. A test at the lower, E1, frequency, with 50 watts applied, resulted in very high distortion values of 13.3% second, 90% third, 9% fourth, and 20% fifth harmonic.
Figure 10 shows the A2 (110-Hz) harmonic data. At full power, the second harmonic reached a moderate 9%, while the remaining harmonics are 1% or lower. With 50 watts input, the system reaches a quite usable 100 dB SPL at 1 meter at 110 Hz. The A4 (440-Hz) harmonic data is shown in Fig. 11. The second-harmonic distortion reached only 3% at full power, with the third much lower, at 1.3%, and the fifth at a low 0.8%.
Figure 12 shows the Model l's IM generated by tones of 440 Hz (A4) and 61.7 Hz (B1) of equal power, covering the range from 0.1 to 50 watts. The IM distortion reaches a high level of 27% at 50 watts.
The Model l's short-term peak-power input and output capabilities are shown in Fig. 13 as a function of frequency, measured using a 6.5-cycle, third-octave band width tone burst. The peak input power was calculated by assuming that the measured peak voltage was applied across the speaker's rated 8-ohm impedance.
The peak power handling starts out at about 17 watts at 20 Hz, rises to 70 watts at 63 Hz, reaches a plateau of 1,200 watts between 125 and 315 Hz, and then increases to about 3,200 watts above 800 Hz.
With room gain, the maximum peak output SPL of the system starts at 80 dB at 20 Hz, rises rapidly to the mid-110s be tween 100 and 315 Hz, and then increases to the 120-dB range above 400 Hz. In the bass range with room gain, 110 dB is attained at about 90 Hz, and 120 dB is not reached until 450 Hz. The peak output of the Model 1 in the bass range places it in the bottom third of the systems I have tested, but ahead of some other small-format systems.
Use and Listening Tests
Initial listening to the Model 1 disclosed a well-balanced and smooth sound but with a lightweight low end. However, the low-end output of the system competed well with, and sometimes surpassed, a number of other small systems I have listened to and tested. Although the Dana's low-bass output was nil, it was not easily overloaded even by material with lots of low end. Even though the system did not shake the walls on pipe-organ material, it still had a satisfying level of bass. The Mod el l's sensitivity was essentially equal to that of my reference B & W systems.
Listening equipment included my Onkyo and Rotel CD players, Krell's KRC preamplifier and KSA-250 power amp, and Straight Wire Maestro cabling plus the B & W 801 Matrix Series 3 speakers as references. The Model is were set up on 28-inch-high stands, which placed the system's axis (the center of the box) about 36 inches high, and were aimed at my listening location. They were placed in my usual locations, well away from the side and rear walls of my listening room. The speakers were separated by about 8 feet, and listening was done from my couch, 10 feet away.
Some listening was done with the systems assisted by the Sub-1 subwoofer, which was located midway between the Model is but closer to the wall. With the subwoofer installed, low-frequency power handling and output were much improved. My usual speaker positions, far from the walls, are not conducive to getting all the available low end out of small systems such as the Model 1. With the Dana's placed much closer to the rear wall, the bass response improved, but this was at the expense of imaging and response smoothness, which were directly affected by the higher level reflections from surfaces immediately behind the speakers.
The operating instructions for the Model 1 are on a very brief, single 8 1/2 x 11-inch page printed on both sides. Speaker placement information consisted essentially of the sentence "All speakers, including the Model 1, will exhibit better imaging, soundstaging, and tighter bass if mounted on stands at ear level and located away from the back and side walls." The instruction sheet did mention that the Model 1 is not as cable-sensitive as most loudspeakers, and suggested that the user experiment with double runs (two positive, two negative) of 20-gauge, solid-core cable.
In my installation, the Straight Wire Maestro cables were significantly more expensive than the loudspeakers to which they were connected! First serious listening was done with the London Brass playing Spanish compositions from iViva Espana! (Teldec 9031 76990-2). Here, the CD did not have any heavy bass (nor did the material require it), and thus was well matched to the capabilities of the Model Is. On this program material, the Model is did surprisingly well compared with the B & W systems, producing a quite realistic brass sound, at near lifelike levels, coupled with a quite pleasing overall balance. The sound of the percussion and castanets on track 2 was nearly in distinguishable from the B & W's reproduction. The African drums and Indian percussion sounds on the world music CD The Goat Also Gallops, by Natraj (Doria Discovery DIS-80124, highly recommended for those into jazz with an African/Indian influence), were also rendered quite realistically by the Dana Audio speakers.
On the pink-noise stand-up/sit-down test, the Model is did quite well and exhibited only moderate midrange tonal changes on stand-up. Horizontal coverage on pink noise was excellent. Although the Model l's pink-noise spectral balance was quite close to the B & W's, the Model 1 speakers had much less bass and some lower midrange emphasis. Some tonality was also evident, which indicates a non-smooth response.
On third-octave band-limited pink noise, the Dana Audio systems generated no us able bass output from 20 to 31.5 Hz. Some fundamental output was noted at 40 Hz, with slightly more at 50 Hz. It was better at 63 Hz, with full output only available at the 100-Hz band and higher. Placing these speakers much closer to the rear wall significantly increased the low bass output.
On wideband pop and rock material, the Model is could be turned up quite loud but sounded somewhat congested when the material had any high-level bass. On classical male and female vocal material, such as Bach: Secular Cantatas (Dorian DOR-90199), the Model is did quite well and presented a clean, full-bodied but somewhat up-front sound. Mid/high balance, however, was quite accurate and quite close to that of the B & Ws.
The Model Is should seriously be considered as the main speakers in a low-bud get situation or as a second system for a bedroom, etc. With bass augmentation, such as Dana Audio's Sub-1 or a good separate subwoofer or two, an excellent system can be put together that competes well with much higher priced contenders. The Model is provided much musical enjoyment, and considering their cost, the enjoyment was much multiplied. Give them a listen.
-- D. B. Keele, Jr.
(Source: Audio magazine, Feb. 1995)
Also see:
Celestion SL-600 Loudspeaker (Feb. 1985)
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