In the beginning there was foldedhornbassreflexacoustic Suspension.
And now BIC VENTURI
For about 40 years, speaker designers have been juggling the characteristics they wanted from speakers: Compact size, high efficiency, high power-handling, and deep ranging, pure, clean, gut-reaction bass.
They tried folded horns: efficient, clean, good power-handling, but too large for most homes, quite expensive. They tried the bass reflex: Efficient, compact, but limited by uneven, one-note bass. Ditto the labyrinth, but far less efficient.
Today's favorite, the acoustic suspension: Compact, smooth, deep-ranging bass.. But inefficient (requiring costly, high-powered amplifiers)and limited dynamic range.
A virtue here, a virtue there--but all with corresponding compromises.
Ironically, the principle that combines these objectives into one compact cabinet has been around for some 180 years: The VENTURI principle of fluid motion transformation, reapplied in a form better suited to acoustics (patents pend.). Our simplified diagram shows how the scientifically formulated VENTURI coupled path functions as a step-up transformer. Up to 140 times more bass energy comes from the duct than comes directly from the woofer. And bass is reinforced broadly over the low frequency spectrum, not at a single "tuned" frequency.
The BIC VENTURI coupled path also operates as a low pass acoustic filter, cleansing harmonics and distortion components from the bass waves. So, the bass not only goes down further and is louder, it's cleaner and more natural. And requires a fraction of amplifier power of other speakers of comparable size and performance.
Yet, even though BIC VENTURIS need less amplifier power, they can handle more. This new principle eliminates compromises in cone, suspension and magnetic design to "match" cabinet characteristics.
Above the woofer, you can see our midrange. To match the exceptional high efficiency of the bass section, we had to invent a new horn, combining two different types of flare, conical and exponential, BICONEX' (pats pend.). It provides wide, smooth dispersion in both horizontal and vertical planes, so placement in the home won't be critical. BICONEX covers the full midrange to well beyond 15,000 Hz without crossover network interruptions, for distortion-free, smooth response.
Our super tweeter handles just a half octave from 15,000 to over 23,000 Hz. While you can't hear single frequency tones in that range, the accuracy of musical "timbre" depends upon those frequencies being added in proper proportion to the complex tones you do hear. An important subtlety.
Because you hear less bass and treble at low and moderate levels, we built a DYNAMIC TONAL COMPENSATION circuit (patents pending) into the speaker. It adjusts speaker frequency response as sound pressure output changes, automatically. Amplifier "loudness contour" controls can't do that. Result: aurally "flat" musical reproduction always, regardless of volume control settings.
Our Formula 2 is the most efficient speaker system of its size, yet can be used with amplifiers rated up to 75 watts per channel! Formula 4 has deeper bass and can be used with amplifiers up to 100 watts.
Formula 6, the most efficient, will handle 125 watts. The Formula 1, newest and smallest model, handles up to 50 watts and needs only a few watts input for clean, high level sound. Hear them at franchised BIC VENTURI dealers. Or write for brochure:
BRITISH INDUSTRIES CO. , Westbury, N.Y. 11590, Div. of Avnet, Inc.
(Source: Audio magazine, Mar. 1975)
Also see: B-I-C VENTURI speakers (Aug. 1975)
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