Multi-driver in-phase bipolar array loudspeaker

• US 5,887,068 A
• Filed: 01/05/1996
• Issued: 03/23/1999
• Est. Priority Date: 01/05/1996
• Status: Expired due to Term

• Current Assignee: Definitive Technology
• Original Assignee: Definitive Technology
• Inventors: Johnston, Robert G., Givogue, Don E.
• Primary Examiner(s): CHIN, VIVIAN C
• Application Number:
  US08/583,504
• Time in Patent Office: 1,173 Days
• Field of Search: 381/97, 381/89, 381/90, 381/188, 381/205, 381/24, 381/182, 381/98, 381/99, 381/96, 181/144, 181/145
• US Class Current: 381/89
• CPC Class Codes: H04R 1/20 Arrangements for obtaining desired frequency or directional characteristics for stereophonic purpose H04R5/00

Abstract

This loudspeaker system overcomes the disadvantages of prior art bipolar loudspeaker systems in which the front and rear-mounted driver(s) are connected with the same electrical phase. It compensates for the undesirable cancellation and reinforcement effects of prior art in bipolar loudspeaker design caused by the interaction of the front and rear acoustical output of the two drivers over certain frequency ranges. The introduction of a third side-mounted driver(s) to an enclosure whose depth exceeds its width when viewed from the front compensates for the usual cancellations and reinforcements of acoustic level that would normally occur in previous bipolar loudspeaker designs. This loudspeaker uses electronic, electrical and acoustical frequency-dividing networks to allow compensation of the acoustic level and the interaction of the front, rear and side-mounted driver(s) in such a way as to provide a nearly constant acoustic level over the entire operating range of the loudspeaker. The arrangement of the three drivers and their associated electronic, electrical and acoustical frequency-dividing networks allows the attainment of a loudspeaker with a bipolar radiating characteristic that does not possess the previously unavoidable peaks and dips in acoustical output caused by reinforcement and cancellation of the acoustic outputs from the front and rear-mounted driver(s). In this loudspeaker, the low-frequency range is covered by the side-mounted driver(s) and the upper frequency range is covered by the front and rear-mounted driver(s).

Claims

1. A multi-driver in-phase loudspeaker system comprising at least three speaker drivers mounted in a unitary enclosure, said drivers comprising at least one front-facing driver mounted on a front baffle of said enclosure, at least one rear-facing driver, mounted on a rear baffle of said enclosure, said rear baffle oriented substantially opposite said front baffle, and at least one side-facing driver mounted on a side baffle of said enclosure, a frequency dividing network comprising a front and rear-mounted driver network, which controls a first frequency range at which said front and rear-mounted drivers operate and a side-mounted driver network, which controls a second frequency range at which said side-mounted driver operates, wherein said first frequency range is higher than said second frequency range and overlapping said second frequency range in an intermediate range of common, frequency coverage, and a means for completely acoustically separating said front rear and side-mounted drivers within said enclosure to prevent internal interaction of the driver'"'"'s acoustical outputs.

2. The multi-driver in-phase loudspeaker system of claim 1, wherein said means for completely acoustically separating comprises at least one soundwave-impermeable internal cabinet partition completely separating said front and rear-mounted drivers from said side-mounted driver.

3. The multi-driver in-phase loudspeaker system of claim 2, wherein said means for completely acoustically separating comprises soundwave-impermeable internal cabinet partitions separating said front, rear and side-mounted drivers from each other.

4. The multi-driver in-phase loudspeaker system of claim 1, wherein said acoustical separation means comprises acoustical insulating backplates included with said front and rear-mounted drivers to completely separate said front and rear-mounted drivers from said side-mounted driver.

5. The multi-driver in-phase loudspeaker system of claim 1, wherein all of said drivers included in said system are connected in the same electrical phase relationship with respect to each other in an intermediate range of common frequency coverage.

6. The multi-driver, in-phase loudspeaker system of claim 1, wherein said frequency dividing network is an electronic network.

7. The multi-driver, in-phase loudspeaker system of claim 1, wherein said frequency dividing network is an electrical network.

8. The multi-driver, in-phase loudspeaker system of claim 1, wherein said frequency dividing network is an acoustical network.

9. The multi-driver in-phase loudspeaker system of claim 1, wherein said frequency dividing network is a combination of electronic, electrical, or acoustical networks.

10. The multi-driver in-phase loudspeaker system of claim 1, wherein said front and rear baffles have a first width and said side baffle has a second width, said second width being substantially wider than said first width.

11. The multi-driver in-phase loudspeaker system of claim 1, wherein a combined acoustical output of said front, rear and side-mounted drivers, when measured on axis from the perspective of said front-mounted driver(s) in an anechoic or semi-anechoic environment, will produce an acoustical output level that is substantially constant in nature over the entire operating range of frequencies for which said loudspeaker system is utilized.

12. The multi-driver in-phase loudspeaker system of claim 1, wherein said second frequency range is substantially below a range where directionality of sound coming from said side-mounted driver has any significance.

13. The multi-driver in-phase loudspeaker system of claim 1, wherein said front and rear-mounted drivers are connected in the same electrical phase relationship with respect to each other.