Now BIC VENTURI puts to rest some of the fables, fairytales, folklore, hearsay
and humbug about speakers.
Fable
Extended bass with low distortion requires a big cabinet.
Some conventional designs are relatively efficient, but are large. Others are small, capable of good bass response, but extremely inefficient. The principle of the BIC VENTURI systems (pat. pend.) transforms air motion velocity within the enclosure to realize amplified magnitudes , of bass energy at the BIC VENTURI coupled duct as much as 140 times that normally lommagger0 derived from a woofer (Fig. A). And the filtering action achieves phenomenally pure signal (Scope photos B & C). Result: pure extended bass from a small enclosure.
B--Shows output of low frequency driver when driven at a freq.
of 22 Hz. Sound pressure reading, 90 dB. Note poor waveform.
C--Output of venture coupled duct, (under the same conditions as Fig B.) Sound pressure reading 111.5 dB, 1140 times more output than Fig. B.) Note sinusoidal (non-distorted) appearance.
Fairytale
It's okay for midrange speakers to cross over to a tweeter at any frequency.
Midrange speakers cover from about 800 Hz to 6000 Hz. However, the ear is most sensitive to midrange frequencies. Distortion created in this range from crossover network action reduces articulation and musical definition.
BIC VENTURI BICONEX horn (pat. pend.) was designed to match the high efficiency
of the bass section and operates smoothly all the way up to 15,000 Hz, without
interruption. A newly designed super tweeter extends response to 23,000 Hz,
preserving the original sonic balance and musical timbre of the instruments
originating in the lower frequencies.
Folklore
Wide dispersion only in one plane is sufficient.
Conventional horns suffer from musical coloration and are limited to wide BICONEX horn angle dispersion in one plane.
Since speakers can be positioned horizontally or vertically, you can miss those frequencies so necessary for musical accuracy.
Metallic coloration is eliminated in the BICONEX horn by making it of a special inert substance.
The combination of conical and exponential horn flares with a square diffraction mouth results in measurably wider dispersion, equally in all planes.
Hearsay
A speaker can't achieve high efficiency with high power handling in a small cabinet.
It can't, if its design is governed by such limiting factors as a soft-suspension, limited cone excursion capability, trapped air masses, etc. Freed from these limitations by the unique venturi action, BIC VENTURI speakers use rugged drivers capable of great excursion and equipped with voice coil assemblies that handle high power without "bottoming" or danger of destruction. The combination of in creased efficiency and high power handling expands the useful dynamic range of your music system. Loud musical pas sages are reproduced faithfully, without strain; quieter moments, effortlessly.
Humbug
You can't retain balanced tonal response at all listening levels.
We hear far less of the bass and treble ranges at moderate to low listening levels than at very loud levels. Amplifier "loudness" or "contour" switches are fixed rate devices which in practice are defeated by the differences in speaker efficiency. The solution: Dynamic Tonal Compensation. This circuit (patents pending) adjusts speaker response as its sound pressure output changes with amplifier volume control settings. You hear aurally "flat" musical reproduction at background, average, or ear-shattering discoteque levels--automatically.
A system for every requirement
FORMULA 2. The most sensitive, highest power handling speaker system of its size (19 3/4 x 12 x 11 1/2)”. Heavy duty 8" woofer, BICONEX mid range, super tweeter. Use with amplifiers rated from 15 watts to as much as 75 watts RMS per channel. Response: 30 Hz to 23,000 Hz. Dispersion: 120°x120°. $98 each.
FORMULA 4. Extends pure bass to 25 Hz. Has 10" woofer, BICONEX midrange, super tweeter. Even greater efficiency and will handle amplifiers rated up to 100 watts. Dispersion: 120°x120°. Size: 25 x 13.25 x 13”. $136 each.
FORMULA 6. Reaches very limits of bass and treble perception (20 to 23,000 Hz). Six elements: 12" woofer complemented by 5" cone for upper bass/lower midrange; pair of BICONEX horns and pair of super tweeter angularly positioned to increase high frequency dispersion (160°x160°). Size: 26 1/ x15 3/4 x 14 ¼” $239 each.
Sturdily constructed enclosures. Removable grilles in choice of 6 colors. Optional bases for floor standing placement. Write for brochure A- 4 .
Audition today's most advanced speakers at your BIC VENTURI dealer.
BRITISH INDUSTRIES Co., Inc.
Westbury, New York 11590.
A division of Avnet, Inc., Canada: C.W. Pointon Ont.
BIC VENTURI
(Source: Audio magazine, Apr. 1974)
Also see: B-I-C Speaker Systems (Nov. 1978)
Leslie Speakers, Electro Music/CBS Inc. (Apr. 1974)
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