Ohm Acoustics CAM 16 Loudspeaker

Saturday, April 1, 1989 CAM/PRO-16
Publisher: Stereophile | Author: John Atkinson

I like Brooklyn. I even got married under the shadow of the Brooklyn Bridge! (Almost the exact spot where Cher’s grandfather let his dogs howl at the moon in Moonstruck. And if you’re ever in the Park Slope area, check out McFeeley’s for brunch.) I could be forgiven, therefore, for having a soft spot for any Brooklyn manufacturer, including Ohm Acoustics. Except that the only Ohm model I have heard was the omnidirectional Ohm Walsh 5 (favorably reviewed by Dick Olsher in Stereophile in 1987, Vol.10 No.4, and 1988, Vol.11 No.8), and the omni principle is something that I have never found to work, or at least to give me what I feel necessary in reproduced sound. The Ohm Model 16, however, is one of three more conventional Coherent Audio Monitor (CAM) speakers intended to offer good sound at an affordable price: $300/pair

In its basics, it is no different from hundreds of other cheap speakers in that it uses a 6.5” polypropylene-cone woofer in a reasonably small reflex enclosure. It is unique in the treble, however, as it features a plug-in tweeter module, this similar to a black goose egg lying on its side, on the cabinet top. The tweeter itself is a small ferrofluid-cooled plastic dome/cone, with a plastic phase plate in front of its center, and the entire egg can be swiveled around a complete 360° circle. (The positions facing the rear are less useful, of course, but a ±75° scale on the unit’s rear enables the egg to be aimed at the listener on an eggsactly repeatable basis—chuckle, chuckle.) Both electrical connection and mechanical mounting are via a gold-plated ¼” phone jack. The shape of the egg is said to provide an even, wide directivity for the tweeter, resulting, with its ability to be rotated laterally, in the ability to create good stereo images over a wider-than-normal listening area. (Off-center listeners are more on-axis with respect to the farther egg and more off-axis the nearer, allowing the precedence effect to be offset to some extent by the increased amplitude of the farther unit.)

The reasonably sized, black woodgrain-vinyl–wrapped cabinet is braced front-to-back and has its main panels mass-loaded with particle-board offcuts. Its front edges are beveled to optimize diffraction, something also aided by the frameless grilles which push-fit into a rectangular slot in the front baffle. The polypropylene-cone woofer appears to have a second magnet glued to the rear of the first, has a plain felt dust cap and a frame damped with Tufflex material, and is mounted at the top of the baffle, with a 2”-diameter, 9”-deep circular port beneath it. The enclosure is loosely filled with what appears to be cotton wadding.

No details on the crossover were provided, but a visual inspection of the components, glued to a board mounted on one of the cabinet sides, suggested first-order slopes. Quality is basic, with a single air-cored coil in the woofer feed and non-polarized electrolytics in the tweeter filter. Nearfield measurements indicate an approximate crossover frequency between 1600Hz and 2kHz. Internal wiring uses various gauges of multistrand cable and speaker cable connection is via—ugh—spring-loaded terminals.

The sound
The Ohms were set up on the 24” Chicago speaker stands, well away from the side-walls and about 30” from the rear wall. Set the speakers on much lower stands and the tweeter starts to sound disconnected; listening on the axis just below the tweeter seemed to give the best integration between the two drive-unit outputs. Initially, I faced the bass cabinets straight ahead with the tweeter egg facing the listening position. This worried me a little in that when the egg is angled to any significant extent, the top of the woofer enclosure presents an immediate obstacle in its acoustic environment. I therefore angled the entire speaker so that the egg angle did not have to be so severe, but after a number of comparisons I could not hear any significant improvement, even when it came to imaging precision (though the CAM 16 is not outstanding in this respect). It would appear that my worries were egg-zaggerated.

One of my first tests for any speaker is to play a selection of recorded male speaking voices. The Ohm 16 came off quite well here, the main identifiable characteristics being a degree of chestiness in the upper bass, a slight cone “quack” in the midrange—can’t be a goose egg after all!—and some sibilance emphasis. Overall, the tonal balance was relatively neutral for what, after all, is quite a low-priced design.

Piano recordings, too, feature in my preliminary listening tests for speakers, and here, again, the Ohm did quite well. The left hand was weak and rather indistinct, with a “woodiness” in the lower mids, while the treble clef region acquired a nasal character. There was also some accentuation of tape hiss in the high treble, with some resonant problems apparent around the notes B natural above middle C (494Hz) and C natural just over an octave higher (1046.5Hz), these notes jumping forward out of the image whenever the music touched upon them. The sound was quite “alive,” however, and was more smooth through the transition region between the drivers than with the Spectrum 208Bs reviewed in January. As a result, musical values communicated eggstremely (OK, quite) well. My own Chopin recordings, however, recorded with a single-point technique, revealed the CAM 16s to present too shallow an image, with rather smeared lateral localization, something confirmed by listening to mono recordings. What should have been a precisely positioned, narrow central image became laterally bloated.

Listening to a variety of naturally recorded orchestral recordings, I started to notice a tonal signature, instruments sounding somewhat “shut-in.” Trumpet, for example, acquired rather a hooded, flugelhorn tonality. Bass instruments were too muddy, reproducing with rather a “fuzz,” while strings also shrieked a little in the treble region. Again, image depth seemed restricted, but a wealth of ambient information could be made out. It just didn’t seem to int-egg-rate sufficiently well. (OK, egg-nough, already.)

Dynamics were excellent, almost over-easy, the ’16s playing loud with only a slight sense of strain. Drums had good weight, though snare was a little “quacky” and cowbell lost some of its metallic character. Cymbals acquired rather a hollow quality, the upper treble fizz sounding a little detached.

To sum up, the Ohm CAM 16 does have an identifiable tonal signature, having a rather soft bass, a touch of nasality in the midband with some unevenness, a slightly shut-in lower treble, and some peakiness in the highs. Imaging specificity is only moderate and image depth is poor. However, these faults must be considered minor in view of the low price; overall, the ‘16 is a well-balanced design and none of its problems particularly get in the way of the music.

I must say that, even though I was pleasantly surprised by the sound of the Ohm CAM 16s, $300/pair is really too low a price for any reader of Stereophile to realistically consider purchasing a pair of speakers. The compromises necessary to produce a model in this price range are just too great, in my opinion, even when the designer is obviously talented, as is the case here. For just two or three hundred bucks more, you can buy something offering a true taste of high-end sound—the Magneplanar SMGa, Rogers LS3/5a, Monitor Audio R300/MD, or Spica TC-50, for example. But if you need to be able to recommend a good-value loudspeaker to a non-audiophile friend, a speaker with a basically neutral tonal balance that will work well with inexpensive receivers and amplifiers, that will go quite loud, and has reasonable bass extension, you needn’t look much farther than this Ohm.

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