Multiple driver dynamic loud speaker

{
  "publication_number": "US3824343A",
  "country": "US",
  "kind": "A",
  "title": "Multiple driver dynamic loud speaker",
  "abstract": "A loud speaker assembly capable of producing coherent sound with multiple driver, dynamic loud speakers is provided, which assembly is characterized by sonic frequencies of the mid-range and treble frequency bands being generated by wide dispersion, dynamic transducers which are free-air mounted within an accoustically transparent enclosure. The mounting of all of the transducers in the assembly is preferably coordinated as a function of the rise time characteristics of the transducers by positioning the transducers forwardly and rearwardly in the assembly along their radiating axes with respect to a listening area, in such manner that the sound waves generated by electrical signals simultaneously impressed upon the transducers will be simultaneously impinged upon a point in the listening area equidistant from the radiating axes of the transducers.",
  "claims": [
    "1. A multiple transducer dynamic loudspeaker assembly comprising, in combination, a frame including an acoustically transparent front face, an enclosure within said frame, a bass radiator transducer mounted within said enclosure, strut means mounted within said frame and extending externally of said enclosure, said strut means presenting minimal area in the direction of said front face of said frame, at least two additional direct radiator dynamic transducer members positioned within said frame externally of said enclosure, said at least two transducers being supported solely by said strut means and being, with the exception of the connection to said strut means, completely surrounded by free space, the area within said frame and rearward of said at least two transducers being substantially free of sound reflective surfaces facing the front of said speaker, and a frequency dividing network means for dividing the electrical signals fed to said loudspeaker assembly into at least three discrete frequency bands, and applying an appropriate said band to each said transducer.",
    "2. The loudspeaker assembly in accordance with claim 1 wherein portions of said frame external of said enclosure are substantially acoustically transparent.",
    "3. The loudspeaker assembly in accordance with claim 2 wherein said rear face of said external frame portion is of lesser acoustic transparency than said front face.",
    "4. The loudspeaker assembly in accordance with claim 1 wherein the radiating axes of said transducers are substantially parallel and the radiating surfaces of said transducers are displaced one from the other along said axes in accordance with the rise time characteristics of said transducers a distance whereby the sound wave generated by each of said transducers responsive to an electrical signal simultaneously impressed upon said transducers will simultaneously reach a listener in front of and equI-distant from the axes of said transducers.",
    "5. A loudspeaker assembly in accordance with claim 1 wherein the radiating axes of said transducers are disposed in substantial parallel alignment and are directed toward a listening area forwardly of said front face of said assembly, the radiating diaphragms of said transducers being displaced one from another in inverse relation to the relative rise time characteristics of the transducers whereby the transducer having a longer rise time will be disposed closer to said area, with the diaphragm of each transducer having a longer rise time than another transducer closer to a point within said listening area equi-distant from said diaphragms than each other transducer having a shorter rise time."
  ],
  "cpc": [
    "H04R 1/26"
  ],
  "assignees": [
    "DAHLQUIST J"
  ],
  "filing_date": "1972-11-29",
  "publication_date": "1974-07-16",
  "grant_date": "1974-07-16",
  "priority_date": "1972-11-29",
  "application_number": "US-31053572-A",
  "family_id": "23202948",
  "citations": [
    "DE1042024B",
    "FR1216851A",
    "FR1339664A",
    "US2217279A",
    "US3105569A",
    "US3385929A",
    "US3666041A"
  ]
}