MB Quart MB 280 loudspeaker

A new name to me, West German company MB Quart GmbH is, in fact, the reincarnation of the Peerless loudspeaker company that until 1983 used to be owned by New York–based Electro Audio Dynamics (EAD). The company has been in existence for over 20 years and under either name has an excellent reputation for its drive-unit technology, MB being one of the first manufacturers to offer an OEM metal-dome tweeter. Their 1" titanium-dome unit, for example, was featured in Dick Olsher's Dahlia-Debra DIY design (footnote 1), and I became quite enamored of the effortlessly clean nature of that speaker's treble.

MB opened a US subsidiary company in June 1987 (footnote 2) and offers a range of models ranging in price from $479/pair to $7000/pair. The 280 costs $579/pair and is the second up in that range; it appears typical of West German design in that it features superb cosmetics and finish, real-wood veneer being offered even at this budget price. Was this latter emphasis, rare in the world of "real" hi-fi, achieved at the expense of the sonics? We shall see.

A two-way design, the MB 1", ferrofluid-cooled, titanium-dome tweeter is coupled with an 8", paper-cone woofer in a sealed cabinet. The drivers are almost vertically in-line, the tweeter being slightly offset to the left of the woofer's vertical axis to render the path lengths different and avoid symmetrical HF diffraction patterns. The speakers are not supplied as a mirror-imaged pair, however. The tweeter's fragile dome is given a degree of protection by a plastic phase-plate. Martin Colloms reports that reproduction of the top audio octave is improved if this plate is carefully prized away. The dome, however, is then fully exposed; I doubt that MB Electronics USA will be particularly sympathetic if it then becomes damaged.

The tweeter crosses over to the woofer with second-order, 12dB/octave slopes below 1500Hz. This is a low frequency for a two-way design and will be expected to place demands on the HF unit to handle rather more power than would otherwise be the case. The MB tweeter is said to have a vented chamber behind the dome to lower its intrinsic resonant frequency. The woofer has a long-throw voice-coil and its radiating area is maximized by use of a narrow, butyl-rubber surround.

The cabinet is constructed from a proprietary five-layer wooden laminate veneered on the sides only, the top, bottom, and back being finished in black vinyl, and the front baffle in what looks like black velvet. This is actually a flock with the fibers electrostatically aligned at 90° to the surface, which is said to give a "sharper image focus," presumably by absorbing high-frequency waves traveling parallel to the baffle. The fiber length appears to be too short to offer any real resistance to audio-frequency sound, however. Also affecting diffraction will be the two solid-wood vertical strips flanking the baffle, the presence of which raised my eyebrows somewhat. Putting such acoustic obstacles in the tweeter environment is not particularly a good idea. The grille, too, consists of brown cloth stretched over a 5/8"-thick particle-board frame, with no attempt made to profile the frame edges near the tweeter. Auditioning, however, was carried out with the grilles in place. Electrical connection is via angled, knurled binding posts inset on the rear panel.

The sound
The first thing I do in a review is to listen to how the loudspeaker handles pink noise (noise with equal energy per octave, such as FM interstation noise). On the tweeter axis, though relatively neutral, the MB Quart 280 did appear to have a slight "double-hump" response, with accentuation in the lower midrange and the low treble/upper midrange. The high-frequency content of the sound rose with the listening axis, though with the appearance of a suckout around crossover, and the amount of low-treble emphasis could be reduced by moving off-axis to the side. After some experimentation, I ended up with the speakers firing straight ahead, the listening seat then being 20–30° off-axis horizontally, with the listener's ears just below the tweeter axis, which gave the smoothest transition between the drive-units. Sitting below that axis leads to the HF rapidly becoming depressed in level. The 24" stands were therefore best suited to the MB 280s and were used for all the listening tests.

The low frequencies were noticeably lightweight, so I experimented with a variety of distances from the rear wall, ranging from 4' to around 16", to see if I could arrange for some expeditious boundary reinforcement. The closest spacing sacrificed some of the imaging accuracy but did give the best mid- to upper bass balance.

First impressions were very favorable. String tone was reasonably natural and voice reproduction was unfatiguing. Male voice, too, was neutral, while female voice lacked any emphasis of sibilance. Imaging was less precise laterally than I would have liked, however, particularly in the midrange—certainly it was nowhere near the standard set by such models as the three-times-the-price Acoustic Energy AE1. Presentation of image depth, too, was less than satisfactory, even when the 280s were positioned well out in the room to minimize the contribution of rear-wall reflections. With my own crossed–figure-eight microphone recordings, good loudspeakers present a well-focused image having a considerable degree of soundstage depth. The 280s brought everything forward, almost to the plane of the loudspeakers.

The bass, though lightweight, was typical of a well-tuned infinite-baffle design: tight and well controlled, without any obvious overhang. In my opinion, it suited LP playback, which tends to be rich in the low bass, better than it did the drier-sounding CD. Dynamics seemed rather suppressed, however, with kick drum on track 13 on the HFN/RR Test CD (footnote 3) being overcrowded by the tom-tom sound an octave or so higher. Moving up into the lower midrange revealed a "warmish" balance, almost an "aww" coloration, which obscured instrumental tonal identities lying in this region. Viola took on some of the cello's characteristic tone color; cellos sounded as though they had mutes on.

High frequencies were smooth and extended, though perhaps a little reticent. More problematic, however, was the nature of the 280's low-presence region which could sometimes become too forward. Listening to the Chopin Waltz on the HFN/RR CD revealed that the region between G and B-flat above the treble staff was too lively, these notes being more forward than the regions above and below. It is a rare speaker that presents this particular track with an even emphasis throughout the treble clef. Nevertheless, the MB 280 was too lively for my tastes, though I am sure that many listeners will enjoy this added "presence," particularly with nonclassical music.

Overall, I feel that the MB 280 offers quite a lot of loudspeaker at a very affordable price. Well-engineered and excellently finished, it offers a basically good sound. However, it falls down in areas where I am particularly sensitive, those involving stereo imaging and lower-midrange coloration. It does rise above its similarly priced competition in having a fundamentally excellent tweeter, capable of smooth and detailed high-frequency reproduction, and it is possible that the next speaker up in the MB Quart range, the three-way MB 390 ($899/pair), which also uses the titanium-dome HF unit, would be a better all-round performer.

Footnote 1: See Stereophile Vol.10 No.4 (June 1987), p.65; and also Vol.10 No.6 (September 1987), p.83.

Footnote 2: MB Quart was bought by Rockford Fosgate in 2000, but in September 2004, Rockford discontinued the German operations of its subsidiary MB Quart GmbH "due to continued losses at Rockford's MB Quart GmbH subsidiary in Germany." After one year in receivership, in mid September 2005, MB Quart was acquired by Maxxsonics USA, Inc, who established Maxxsonics GmbH. See this 2017 thread on DIYMobileaudio.com. In 2022, MB Quart manufactures in-car speaker systems; see mbquart.com.

Footnote 3: This test disc, which I produced in 1985 while Editor of HFN/RR, is no longer available. At the time this review was published it was distributed in the US by Music and Sound Imports, Huntingdon Valley, PA 19006.

MB Quart
851 E Park Ave
Libertyville, IL 60048

Jack L's picture

Just out of curiosity !

Listening is believing

Jack L