These very practical small sound cabinets are particularly suitable for the travelling cabaret act or gigging band who are seeking a clean and natural sound. Designed by Dr. Amar G. Bose's team of engineers, these 8" x 4½" "full range" loudspeakers, each with an enormous 10oz ceramic magnet, use a very original design to give very high sensitivity (combined with strong treble and bass, and an impedance figure of 8 ohms).
The system is basically designed to use four 4½" drivers so that each driver is a midrange unit. The set of four, closely coupled acoustically, act in unison to form a "single large cone" area to generate a very strong bass. The high-treble is good, clean and undistorted.
By duplicating the arrangement in each cabinet (measuring 19 3/8" x 15" x 13" and weighing 43lbs), Dr. Bose has also achieved a wide area of horizontal distribution, much better than the usual spread from a single loudspeaker cabinet.
On a subjective test, we found that these units had a much more even frequency response than when used in conjunction with the equalization unit provided. They successfully handled deep bass and high-sibilant treble without boomy bass or peaky treble.
Electrical contact is made via a jack socket, on the back of the cabinet, fitted with a cover which seals the socket when not is use. The strength of the mechanical construction is just about the best we have ever seen but most unorthodox. The cabinets are made of heavy duty plywood covered with vinyl and all the external corners are covered with strong vulcanized fibre edging and riveted on metal corner and angle fittings. A carrying handle is fitted on the top which gives the unit the appearance of being a trunk when the lid is in place and latched on with the four strong metal retaining clips.
The metal-boxed equalizer unit is carried in the lid of one of the speaker units in the special compartment provided.
The equalizer gives about 12-15dB main in the bass and treble whilst maintaining the middle @ 0dB. It operates from the mains A.C. power and corrects the tone of the ingoing signal (between sound-source and the power amp) to correct for the predominantly "middle" sound when all the tone controls are @ 0dB.
One of the good features, we found, was that due to the unusually even frequency response, no single note or group of notes will accidentally "peak" in sympathy to certain notes causing feedback.
This means that one can achieve a very much higher level of volume without risk of feedback.
The makers claim the following figures: maximum amplifier power, 270w. (Rms.); maximum music signal, 125w.; maximum continuous signal, 90w. — with no bass.
One can either use the lids of the cabinets as pedestals for the Bose 800 speakers or mount them on the metal atlas SS-2 stand.
Both the hardware and the sound quality of this system are superb. The evenness of the audio frequency spectrum helps avoid spurious feedback up to the point where feedback over the whole audio-spectrum occurs.
Retail Price £390
mu:zines is the result of thousands of hours of effort, and will require many thousands more going forward to reach our goals of getting all this content online.
If you value this resource, you can support this project - it really helps!