by JAMES T. FRANE
Company Address: 535 Getty Court, Bldg. A, Benicia, Cal. 94510.
Founded in 1954 by Edgar Villchur and Henry Kloss, Acoustic Research (AR) became well known for its creation and use of the acoustic-suspension type enclosure. This design uses the spring force of the air in a hermetically sealed cabinet to control the motion of a driver. Acoustic suspension enables designers to achieve extended bass, with low distortion, using a relatively small enclosure.
In the early 1950s, most speakers that had good bass extension were expensive and required large cabinets. The smaller size AR speakers became quite popular, especially with the advent of stereo, when two speakers were needed. The AR development of dome tweeters in the late '50s added to the popularity of the company's speakers, as dome drivers improved stiffness and dispersion, compared to cones.
AR is now part of International Jensen and recently relocated from Massachusetts to California. Its cur rent offerings range from a small two-way system with a 5 1/4-inch woofer design to a three-way with a 12-inch woofer. They are embodiments of the company's original design concepts, and improved by the use of the latest technology in drivers. A powered subwoofer and a home theater center-channel speaker round out the line. AR's design goals include wide frequency response and balanced power output across the frequency spectrum.
The 338 is about in the middle of a range of new AR designs. It is of traditional "bookshelf' speaker size and is AR's smallest three-way mod el. It utilizes a 3/4-inch dome tweeter, a 1 1/2-inch dome midrange, and an 8-inch paper cone woofer. The drivers are mounted vertically on the front baffle of an enclosure that is 19 inches high, 10 1/2 inches wide, and 9 inches deep. The tweeter and mid range are on a common vertical centerline, offset to 4 1/2 inches from the cabinet edge, and the woofer is horizontally centered near the bottom of the baffle.
Mirror images of each other, the speakers can be placed with the tweeters and midrange drivers to ward either the inside or the outside cabinet edges. The review pair was well finished on all sides in cherry wood vinyl (black vinyl is also available). Input connection is via two gold-plated five-way binding posts that are 1/4 inch on center, to accept dual banana plugs, and located in a recessed insert in the lower back baffle. The black plastic grille frame is covered in black double-knit cloth, and the grille is held about 0.25 inch away from the front baffle, on posts inserted into sockets.
The size of the enclosures requires the 338s to be elevated in order to position the tweeters at about ear level, and this is how I auditioned them. Their sensitivity is rated as 86 dB with a frequency response of 55 Hz to 20 kHz, ±3 dB.
I placed the 338s 7 1/2 feet apart and about 9 1/4 feet from the listening position. The backs of the speakers were 2 1/2 feet from the back wall, and the nearest side wall was about 1 3/4 feet from them. I tried them f both facing straight ahead and angled to ward me, with and without the grilles. (The 338s have an appealing appearance even without the grilles, although the dome drivers will then be exposed to curious fingers.) I found the sound to be better with the speakers toed in and pointing directly at the listening position, sans grilles, and placed so that the tweeter and midrange were to ward the inside edges. I tried the 338s at various distances from the rear wall and found that the closer they were to it, the shallower the soundstage became.
The speakers were driven with a Carver TFM-42 power amp controlled by a Carver CT-17 tuner/preamp. The interconnect cables were Monster Cable, and loudspeaker cables were Kimber 4PR. A Sony CDP-C315 CD player, a Dual CS5000 turntable with Shure's V15 Type V cartridge, and the Carver tuner were used as signal sources. I listened to acoustic jazz, vocals, classical, and vintage rock music.
Mechanical components can benefit from a break-in period, depending on the time required for their materials to reach an equilibrium point. Right out of the box, the ARs had a well-balanced low-frequency response that extended down to the mid-50-Hz range. This might have been because the already compliant suspension of the acoustic-suspension woofer didn't require much of a break-in period. Initially, the sound seemed to emanate directly from the speakers, resulting in a somewhat "closed in," boxy sound, but after a few days of use, the soundstage broadened and deepened.
As more time passed, the stage stretched be tween, behind, and often to the outsides of the speakers when I played good source material. Any tendency toward boxiness disappeared. This change might have occurred as the midrange driver suspensions loosened and stabilized with use. The bass output did not change character over time, although it eventually reached down into the mid-40 Hz range. The highs decreased slightly when I moved from a seated to a standing position, particularly with pink noise. Horizontal power output seemed consistent over a wide area, as I found good listening positions virtually anywhere between the speakers. At $649.95 a pair, these are not high-priced speakers, and the price belies their performance.
I frequently attend live music performances, using them as my standard of reference. Although the ARs didn't convince me the music was live, they acquitted them selves well in terms of tonal balance, dynamics, consistency, and presentation of the performance venue. The differences be tween good and poor recording techniques were readily apparent. The flat bass response allowed the reproduction of male voices without any hint of congestion or "chestiness." Female voices were well reproduced and sounded very natural. Accurate timbre clearly distinguished different instruments. The bite and rasp of a trumpet, the soulful depths of a tenor sax, the scrape of a well-rosined bow on strings, and the spread of a full orchestra were quite realistic, given good recordings.
There was no confusion between the sounds of violins, violas, cellos, and double basses. The high-frequency output was smooth and very extended, without stridency or harshness. The 338s created a very enjoyable listening session, no matter the type of music.
The major area of performance with which some may find fault is in the reproduction of the lowest octave (below 40 Hz).
While larger woofers can add impact, a heightened sense of realism, and the foundation of the lowest musical octave, an 8 inch woofer can move only so much air. Yet although the lowest octave is essentially missing (what is there is at a much de creased level), its absence is neither really detrimental nor likely to be noticed with most music. I have listened to speakers costing more than twice as much as the 338s that were not as musically involving. I listened for long periods of time to the ARs without experiencing any sign of fatigue, often finding myself stopping other activities just to concentrate on the sound.
The AR 338s are very much worth auditioning, and I got very good sound from them after the break-in period.
( Audio magazine, Nov. 1995)
Also see:
Acoustic Research AR98LS Speaker (Equip. Profile, Jan. 1985)
AR M1 Speaker (Equip. Profile, Jan. 1992)
AR (Acoustic Research) MGC-1 loudspeaker (ad, Nov. 1986)
Altec Lansing 511 Speaker (Apr. 1991)
Sheffield Labs--MY DISC (Test Disc) (Nov. 1995)
= = = =