United States Patent [191 Ouvrier 1 Oct. 29, 1974 I 1 SPEAKER SYSTEM [75] Inventor: John Michael Ouvrier, Sylmar,
Calif.
[73] Assigneez' GTE Sylvania Incorporated,
Stamford, Conn.
3,136,383 6/1964 Hopkins 181/31 B OTHER PUBLICATIONS Handbook of Sound Reproduction by Villchur 1957, p. 99 100.
Primary Examiner-Kathleen H. Claffy Assistant ExaminerDouglas W. Olms Attorney, Agent, or Firm-Norman .l. OMalley; Thomas H. Buffton; Cyril A. Krenzer [5 7] ABSTRACT A high fidelity sound reproduction system includes an air-sealed cabinet with an interior divider providing first and second air-sealed compartments with a loudspeaker affixed in air-sealed relationship to each compartment and the loudspeakers electrically connected in parallel for receiving the same signals whereby bass response is enhanced.
3 Claims, 2 Drawing Figures ATENTEUUET 29 I974 I 4., m I I u a a til-I;
I I I I \ooo FREQUENCY (CYCLES/SECOND) ZOTrEOPmFH m SPEAKER SYSTEM BACKGROUND OF THE INVENTION In high fidelity sound reproduction systems, a problem exists in obtaining sufficient bass energy to provide the desired realistic effect. One attempt to provide sufficient bass energy includes the utilization of two or more woofer-type loudspeakers. Moreover, in stereo and multiple-channel systems each signal channel is equiped with a loudspeaker system which includes the above-mentioned plurality of woofer-type loudspeakers.
Although such systems do provide a tremendous amount of bass energy, it has been found that the bass sound reproduction is not fundamental and deep. On the contrary, it has been found that such systems tend to provide a highly distorted bass response which either has an undesirably low resonance or an undesirably high resonance or boom.
Further, the known large speaker systems employing multiple loudspeakers to obtain a large amount of bass energy also have speaker enclosures with a large internal volume. Unfortunately, the large internal volume of the enclosure has a resonance which is too low and fails to reproduce a good deep bass sound. Moreover, the air volume behind the loudspeaker is excessive and consequently, the loudspeaker is not properly airloaded to the rear of the speaker cone. Thus, the speaker cone tends to flap in a haphazard manner and produces undesired distortion.
OBJECTS AND SUMMARY OF THE INVENTION An object of the present invention is to provide an enhanced sound reproduction system. Another object of the invention is to provide an improved loudspeaker system for sound reproduction apparatus. Still another object of the invention is to provide an improved loudspeaker system having multiple air-sealed compartments each having a loudspeaker affixed in air-sealed relationship thereto.
These and other and further objects, advantages and capabilities are achieved in one aspect of the invention by a loudspeaker system having an air-sealed cabinet with at least two air-sealed compartments and a loudspeaker affixed in air-sealed relationship to each compartment. The loudspeakers are electrically coupled in parallel or in series to a single signal source.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a loudspeaker system utilizing the present invention; and
FIG. 2 is a graphic comparison of the loudspeaker system of FIG. 1 and a commonly employed loudspeaker system.
PREFERRED EMBODIMENT OF THE INVENTION For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the accompanying drawings.
In the drawings, FIG. 1 illustrates an air-sealed cabinet or enclosure 5 having front, back, and side members 7, 9, and 11 respectively. Top and bottom members, not shown, are affixed in air-sealed relationship to the above-mentioned front, back and side members 7, 9, and 11. Moreover, a divider member 13 is disposed within the enclosure 5 to provide two air-sealed compartments l5 and 17 of unequal volume.
Bass loudspeakers 19 and 21 are each affixed to the front member 7 of one of the compartments 15 and 17. Also, the'loudspeakers 19 and 21 are parallel or series connected electrically to a single source of signals. Thus, a single sound signal source is utilized to drive both of the loudspeakers 19 and 21. Moreover, each one of the compartments l5 and 17 includes the usual high and mid-range loudspeakers (not shown) affixed to the front member in a manner well known in the art. The air-sealed compartments 15 and 17 each have an internal volume of about 4000 cubic inches with loudspeakers 19 and 21 having a diameter of about l2 inches. Thus, the air-sealed compartments l5 and 17 each have a volume in the range of about 3000-5000 cubic inches and a resonance in the range of about 30-40 Hz.
Preferably, the air-sealed compartments l5 and 17 are of an unequal volume with a first compartment 15 having a resonance of about 30 Hz and the second compartment 17 having a resonance of about40 Hz. Thus, the overall resonance when parallel coupled loudspeakers l9 and 21 are employed will span a rather broad band of between 30 and 40 Hz.
Additionally, FIG. 2 illustrates a percent distortionfrequency chart comparing loudspeaker systems utilizing dual bass loudspeakers in a single large enclosure and dual bass loudspeakers each affixed to an individual smaller enclosure as previously described. As can readily be seen, the dual loudspeakers'affixed to the individual air-sealed compartments have a distortion (Curve A) in the 20 to Hz range which is roughly one-third the distortion (Curve B) of the same dual loudspeakers affixed to a single air-sealed enclosure.
Thus, there has been provided a unique loudspeaker system utilizing dual bass loudspeakers each affixed to individual compartments of an air-sealed enclosure. The system not only provides an improved bass response unattainable in any other known structure but also exhibits a distortion level greatly reduced when compared with other known loudspeaker systems.
Moreover, the reduced air volume or rear air-loading of each of the loudspeakers in the individual compartments greatly inhibits undesired flopping of the loudspeakers and undesired distortion normally occurring in a large single enclosure.
While there has been shown and described what is at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention as defined by the appended claims.
What is claimed is: 1. In a high fidelity sound reproduction system, a single channel loudspeaker system comprising:
an air-sealed cabinet forming an air-sealed enclosure; divider means disposed within said air-sealed enclosure and affixed to provide first and second airsealed compartments, said first and second compartments having unequal volumes and each having a resonance in the range of between 30 and 40 Hz.; and
loudspeaker means including a pair of similar loudspeakers electrically coupled in parallel with each loudspeaker disposed within and affixed to one of said first and second compartments.
3 4 2. The loudspeaker system of claim 1 wherein each a plurality of air-sealed compartments having unone of said pair of loudspeakers has a nominal diameter equal volumes with a resonant frequency of each in of about 12 inches and said first and second compartthe range of about 30-40 Hz.; and ments have a resonance of about 30 and 40 Hz respeca plurality of loudspeakers each being a base speaker tively. 5 having a nominal diameter of about 12 inches, par- 3. In a multiple-channel high fidelity stereophonic allel coupled electrically with one of said loudsound reproduction system, a single channel loudspeakers disposed within and affixed in air-sealed speaker system comprising: relationship to each of said plurality of compartan air-sealed cabinet; ments. divider means disposed within said cabinet to provide P0405) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,845,246 Dated October 29, 1974 Inventor) John Michael Ouvrier It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Col. 4, line 4 delete "base" and insert "bass" Signed and sealed this 29th day of'April 1975.
(SEAL) Attest:
C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks 5: 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,845,246 Dated October 29, 1974 Invento It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Col. 4, line 4 delete "base" and insert "bass" Signed and sealed this 29th day of'April 1975.
(SEAL) Attest C. MARSHALL DANN Commissioner of Patents and Trademarks RUTH C. MASON Attesting Officer