MULTIPLE SPEAKER ENCLOSURE WITH SINGLE TUNING

• US 3,687,220 A
• Filed: 07/06/1970
• Issued: 08/29/1972
• Est. Priority Date: 07/06/1970
• Status: Expired due to Term

• Current Assignee: John Virva
• Original Assignee: John Virva
• Inventors: Virva, John
• Primary Examiner(s): Tomsky, Stephen J.
• Application Number:
  US05/052,164
• Time in Patent Office: 785 Days
• Field of Search: 181/31R,31B
• US Class Current: 181/146
• CPC Class Codes: H04R 1/2857 for loudspeaker transducers

Abstract

A combination of a plurality of high compliance speakers and a rigid single tuned enclosure. The speakers are mounted on different walls at one end of the tuned enclosure, and all of the speakers have their low frequency response augmented by the loading effect of the enclosure. The tuned enclosure has a folded path which is substantially equal to one-quarter of the wave length of the in-air resonance of the speakers. The enclosure is open-ended and has a cross sectional area which is substantially equal to the cross sectional area of the cone of one of the high compliance speakers. The enclosure walls are lined with a sound absorbing medium. By this arrangement sound may be effectively dispersed without employing a high volume speaker enclosure.

Claims

1. In combination;

a rigid acoustic enclosure having a seriEs of panels defining an open-ended tuned column;

sound absorptive means in said column, first and second high compliance loudspeakers having low natural resonances, means mounting the first of said high compliance loudspeakers in one panel of said rigid acoustic enclosure adjacent one end of said column, means mounting the second of said high compliance loudspeakers in another panel of said rigid acoustic enclosure also adjacent said one end of said column, the axes of said first and second loudspeakers forming an angle approximately a right angle with one another, the mean path length of said column being chosen to augment the low frequency response of each of said high compliance loudspeakers, and provide substantial loading therefor, whereby said loudspeakers may be effectively operated at frequencies well below the frequency of said natural resonance said column being folded and having a cross-sectional area which is approximately equal to the cross-sectional area of the cone of one of said high compliance loudspeakers.

2. The combination as set forth in claim 1 wherein said high compliance loudspeakers are mounted at right angles to each other.

3. The combination as set forth in claim 2 wherein said high compliance loudspeakers have substantially the same diameter.

4. The combination as set forth in claim 1 wherein said high compliance speakers have substantially the same natural resonance.

5. The combination of first and second high compliance loudspeakers, an open ended rigid acoustic enclosure having means defining a column for augmenting the low frequency response of said high compliance loudspeakers, said rigid acoustic enclosure being formed of plane walls arranged substantially at right angles to each other and being acoustically lined, each of said high compliance loudspeakers being mounted at adjacent angularly disposed walls at the same end of the enclosure, said column having a cross-sectional area which is approximately equal to the cross-sectional area of the cone of one of said high compliance loudspeakers, the mean path length of said column being chosen to augment the low frequency response of each of said high compliance loudspeakers and provide substantial loading therefor, whereby each speaker is operable at frequencies well below the in air resonance of said speakers.

6. The combination as set forth in claim 5 wherein the path length of said column is substantially one-quarter wave length of a frequency which approximates the in-air resonance of said high compliance speaker.