EPI's 200: Simple, Basic and Musical
The Equipment: EPI Model 200 loudspeaker system in oiled-walnut enclosure.
Dimensions: 17 by 30 1/2 inches (front), 11 1/2 inches deep; intended for vertical use.
Price: $225.
Warranty: "limited," five years parts and labor.
Manufacturer: EPI Division of Epicure Products, Inc., 1 Charles St., Newburyport, Mass. 01950 USA.
Comment: In an era of "special" loudspeaker designs, the new EPI 200 may seem a mite conventional: just a very good two-way speaker with a not very fancy price tag which, as a matter of fact, is rather special in itself. Epicure is quick to point out that the woofer design marks a departure for the company (or for any company located within the citadel of acoustic-suspension design, if not for the industry at large) in that it employs a passive radiator for higher efficiency and more extended bass than has been the rule in past models. Another claim is lowered distortion. Both seem justified.
Efficiency (or sensitivity) is above average at 82 1/2 dB of sound pressure level for the voltage equivalent of 0 dBW (1 watt) into the nominal impedance, measured omni-directionally at 1 meter with the usual noise input employed by CBS. This may sound on the low side in comparison to the on-axis figures we have been showing in the past (it measures 88 1/4 dB by that method); it is certainly higher than one would expect from an acoustic-suspension system. At the equivalent of 0 dBW input, harmonic distortion (both second and third) is in the neighborhood of 0.5% from 60 or 70 Hz up to about 2 kHz; above this range it subsides to an average of 0.2 to 0.3%, while below 40 Hz it rises sharply.
At lower input levels, distortion continues to fall (to the neighborhood of 0.25% in the midbass and bass); at higher levels the second harmonic content rises more rap idly than the more objectionable third harmonic. By the time the speaker is driven to 100 dB (at 300 Hz) second harmonic distortion in the midrange is up to around 2%, while the third still is below 1%. At this input level, how ever, there is a sharp rise to relatively high distortion of both types at around 1.5 kHz. (We suspect that, driven this hard, the tweeter diaphragm may be pushing the limits of linear excursion in its lowest range, since crossover appears to be at about 1 kHz.) Second harmonic distortion above 3 kHz and third above 2 kHz are very well con trolled-generally below 0.5% and 0.3%, respectively.
In steady-state testing, CBS found that it could drive the speaker to 108 dB (with the equivalent of 20 dBW, or 100 watts, of input, the limit of this test) without excessive distortion. On pulses, the 200 handled all the test amplifier could deliver-the equivalent of 29 1/4 dBW (857 watts) peak-and deliver 117 1/4 dB peaks without excessive distortion. This, combined with the very low distortion at low levels, documents the system's excellent dynamic range.
Before going on to factors that are more obviously related to listening quality, we must add a note about impedance. EPI specifies "4 ohms DC, 8 ohms nominal." The curve measured in the CBS anechoic chamber shows the typical double bass-resonance peaks of such a port-equivalent, passive-radiator system, followed by a dip to the lab's nominal impedance, at 4.2 ohms. In the mid range the measured impedance rises to just over 8 ohms at around 1. kHz, only to fall again to a little under 4 ohms between about 4 and 10 kHz. Most musical energy (at least in classical music) tends to fall in the range between approximately 200 and 1,000 Hz-not squarely on the 8-ohm portion of the impedance curve. Conservative practice therefore would suggest that, in considering multiple speaker hookups, you approach the 200 as a 4-ohm model (which precludes paralleled pairs across the outputs of most solid-state amps). And on synthesizer rock, with its very high, high-frequency levels, the impedance dip in the treble may also prove troublesome in parallel hookups.
The anechoic response curves accurately represent what we hear in the listening room. This is a speaker of exceptionally smooth response-very flat (within only ±2 1/4 dB between about 100 Hz and 7 kHz, measured omni-directionally) throughout the upper bass, midrange, and lower treble, with a slight emphasis to the bass just below this range and a gradual (a little less than 6 dB per octave) rolloff above it. Excellent dispersion is maintained out to at least 10 kHz.
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On the back panel (along with color-coded, spring-loaded connections for bared leads) is a three-way tweeter-level switch: NORMAL/LOW/MEDIUM. The lab used the NOR MAL position in testing, and we found we preferred it with most recordings. In MEDIUM. 3 dB is shaved off the tweeter response above about 2 kHz, which might be useful in a room with a hard acoustic edge (though correcting the acoustics themselves would seem preferable). The additional 2 1/2 dB or so that is shaved off by the Low position dulls the sound appreciably and offers no material advantage in the average acoustics of our test listening room.
At the low end, the sound is full and extended. EPI rates response to 34 Hz-a reasonable figure, in our estimation, on the basis both of listening and of the lab data. The hump at the 63-Hz-band anechoic response suggests the possibility of boominess, particularly if the 200 is placed in a corner; but mounted on a wall well above the floor, the speaker gives clean, true bass and excellent balance.
Generally speaking, the sound is exceedingly uncolored.
At high listening levels, piano runs and similar material show a roughness that we ascribe to the aforementioned distortion that appears at the bottom of the tweeter's range when it is driven hard. Aside from this, the EPI 200 is self-effacing; there are no little oddities to nag nor characteristics to bemuse. Whatever the program material, we find ourselves listening to it, rather than the speaker. And that, to our mind, is just as it should be. In its entirely unspectacular way, the 200 is a very fine loudspeaker indeed.
(High Fidelity, Oct. 1977)
Also see:
Technics SB-6000A floor-standing speaker system (Equip Profile, Oct. 1977)
KLH Model 35 speaker (Equip. Profile, Oct. 1977)
Visonik D-50 loudspeaker system (Equip. Profile, Oct. 1977)
ESS Tempest LS-5 loudspeaker system (Equip. Profile, Oct. 1977)