USOO8194886B2 (12) United States Patent (10) Patent No.: US 8,194,886 B2 Knight et al. (45) Date of Patent: Jun. 5, 2012 (54) AUDIO CROSSOVER SYSTEMAND METHOD 4,031,318 A 6, 1977 Pitre 4,031,321 A 6/1977 Bakgaard 4,074,070 A 2f1978 Gaus (76) Inventors: ANSE MIS (GB); FL 4,138,594 A 2/1979 Klipsch nthony Richard Milat, Sarasota, 4,198.540 A 4, 1980 Cizek (US); Kym Martinelli, Sarasota, FL 4,229,619 A 10/1980 Takahashi et al. (US); Giles Garwell Smith, Leicester 4,237.340 A 12/1980 Klipsch (GB) 4,243,840 A 1/1981 Kates 4,282.402 A 8/1981 Liontonia 4,295,006 A 10/1981 Tanaka et al. (*) Notice: Subject to any disclaimer, the term of this 4,315,102 A 2, 1982 E. al patent is extended or adjusted under 35 4,349,697 A 9, 1982 Skabla. U.S.C. 154(b) by 1168 days. RE31,228 E 5/1983 Bose 4,423,289 A 12/1983 Swinbanks (21) Appl. No.: 11/539,210 4,429,181 A 1/1984 Freadman 4.475,233 A 10, 1984 Watkins 1-1. 4,504,704 A 3/1985 Ohyaba et al. (22) Filed: Oct. 6, 2006 4.593,405. A 6/1986 Frye et al. 4,597,100 A 6/1986 Grodinsky et al. (65) Prior Publication Data 4,606,071 A 8/1986 White, Jr. 4,653,103 A 3, 1987 Mori et al. O O 4,771,466 A * 9/1988 Modafferi ....................... 381/99 Related U.S. Application Data (Continued) (60) Provisional application No. 60/724,828, filed on Oct. 7, 2005. OTHER PUBLICATIONS Paul Horowitz and Winfield Hill. The Art of Electronics, pp. 35-39. (51) Int. Cl. Cambridge University Press. HO3G 5/00 (2006.01) (52) U.S. Cl. ............................................ 381/99: 381/98 Primary Examiner — Devona Faulk (58) Field of Classification Search .............. 381/98-99, Assistant Examiner — Disler Paul 381/101, 11, 116 (74) Attorney, Agent, or Firm — Dickinson Wright PLLC See application file for complete search history. (57) ABSTRACT (56) References Cited An audio crossover system and method is disclosed. An audio system includes two driver circuits, one for each of two audio U.S. PATENT DOCUMENTS frequency ranges, e.g., high and low frequency ranges. The 3,646,270 A 2, 1972 Shiga et al. driver circuits are designed to provide a combined frequency 3,657,480 A 4/1972 Cheng et al. response curve that has a pronounced midrange attenuation 3,838,215 A 9/1974 Haynes, Jr. 3,895,193 A T. 1975 Bobb dip, in contrast to prior art designs that attempt to provide a 3,909,531 A 9, 1975 Plummer flat response over all frequency ranges. 3,927,261 A 12/1975 Dahlquist 4,015,089 A 3, 1977 Ishii et al. 20 Claims, 2 Drawing Sheets 2O 50 1OO 200 1K 2K 5K 1 Ok 20K US 8,194,886 B2 Page 2 U.S. PATENT DOCUMENTS 5.937,072 A 8, 1999 Combest 4,897,879 A 1/1990 Geluk 6,281,749 B1 8/2001 Klayman et al. 5,153,915. A 10/1992 Farella 6,381,334 B1 4/2002 Alexander 5,297.212 A 3, 1994 M 1 6,854,005 B2 2/2005 Thiele 5.533,135 A T. 1996 Miyama et al. 7,085,389 B1* 8/2006 Modafferi ....................... 381/99 - - - ary 2004/O122540 A1 6, 2004 Allred 5,568,560 A 10/1996 Combest 2004/0258256 A1 12, 2004 Ruff 5,598.480 A 1/1997 Kim 2005/0063554 A1 3/2005 Devantier et all 5,642,429 A 6, 1997 Janssen 5,781,642 A 7, 1998 Tanaka et al. * cited by examiner U.S. Patent Jun. 5, 2012 Sheet 1 of 2 US 8,194,886 B2 U.S. Patent Jun. 5, 2012 Sheet 2 of 2 US 8,194,886 B2 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Overplot 2O.O 1 OOO 1 OOOO 1OOOOO FIG - 3 2O 5O 1 OO 20 O 500 1 K 2K 5K 1 OK 20K FIG - 5 US 8,194,886 B2 1. 2 AUDIO CROSSOVER SYSTEMAND METHOD The Subject invention has a wider dynamic range. Due to several beneficial design properties, which become evident as RELATED APPLICATIONS a result of the application of the design, system performance as a whole is increased and allows the system to experience a This application claims the benefit of U.S. Provisional fuller and more dynamic signal range. Application Ser. No. 60/724,828, filed Oct. 7, 2005, the entire The subject invention allows for very low listener fatigue disclosure of this application being considered part of the due to lower distortion. Due to the lack of distortion inherent disclosure of this application and hereby incorporated by in the design, the brain does not need to filter unnecessary reference. noise and information present in most speaker systems. The 10 brain only has to process a faithful reproduction of the origi BACKGROUND OF THE INVENTION nal signal, which ultimately causes less listening fatigue for the listener. 1. Field of the Invention The Subject invention provides increased signal to noise The Subject invention provides an audio crossover system ratio. Trying to process distortion along with the signal causes and method. 15 the hearing system to produce its own noise; this manifests 2. Description of the Prior Art itself as a Hash Distortion within the ear. As a result of the The way humans hear Sounds is complex. The auditory distortion not being present, the signal to noise ratio is per canal within the human ear is a long tube and it possesses ceived as wider to the listener. resonances and peaks at certain frequencies. The lowest reso The Subject invention improves amplifier performance. nance is broadly peaked around 3 kHz and appreciable gains The amplifier is able to exert more control over the drivers due are incident from about 2 kHz to 6 kHz. to the relationship between the speaker and the amplifier This frequency range that is accentuated by human hearing when used with the design. This results in an overall lowering coincides with the frequency range in which important lin of system artifacts and maximizes the potential and perfor gual Sounds have their major spectral contents. Sounds like mance of even an entry level amplifier. “p' and “t have very important parts of their spectral energy 25 The Subject invention provides rock solid stereo images within the “accentuated range, making them easier to dis and sound staging. Speakers disappear and provide a more criminate between. To hear Sounds in the accentuated range is complete stereo illusion, with excellent Sound-staging depth Vital for speech communication. resolution and precision image accuracy to a level not previ When exposed to an incident directional sound field and ously definable by the average listener. including diffractive effects of the head, the maximum sound 30 The Subject invention improves dispersion characteristics. pressure level (SPL) at the eardrum can be approximately 7 Regardless of cabinet size, the speakers provide a presenta dB to 20 dB higher than in the incident field, depending on the tion that portrays the scale of the recording more faithfully direction of the Sound. In effect this gives humans a sensitivity than traditional designs, such that large recordings will retain increase within the range from around 2 kHz to 6 kHz of their size even on Small cabinets. between 7 dB and 20 dB. 35 The Subject invention provides a universal design appli Because of this sensitivity, a flat frequency response in the cable to all standard multi-driver designs. Designs can be 2 kHz to 6 kHz area, which is directly within the midrange applied to 2-way, 3-way, 4-way, 5-way and other designs of crossover area, is not required. This sensitivity is illustrated in speakers in any configuration regardless of driver type. the Fletcher Munson curves as shown in FIGS. 1 and 2. If the The subject invention will lower manufacturing costs. No curves of FIG. 1 are turned upside down, as in FIG. 2, they 40 additional special tooling or processes are required to imple provide an indication of how the human hearing attenuates ment the designs and no exotic or precision components are and accentuates parts of the audible frequency range. needed with the subject invention, which results in signifi Typical industry standard crossover designs do not take cantly lower manufacturing costs than with traditional cross this human hearing sensitivity into consideration and, there over designs. fore, attempt to provide a flat response within this area. The 45 The subject invention lowers R&D costs. The designs can Subject invention, in contrast to the typical industry standard be implemented into existing speaker designs and configura flat response design, provides a response that is inversely tions with minimal R&D expense and R&D can be focused on proportional to the increased sensitivity. This inversely pro very specific areas for future development. portional design will indicate a dip in response within the Furthermore, the subject invention follows a unique meth critical area when measured on a spectrum analyzer. 50 odology and have applications in home hi-fi, professional monitors, cinema systems, live sound, commercial sound and SUMMARY OF THE INVENTION AND car audio. The process can provide fresh new concepts in an ADVANTAGES established market that, to date, has provided few true inno Vations. The crossover system and method of the present invention 55 Although the designs of the Subject invention were prima provides numerous advantages over the prior art. rily developed for passive speakers, the principles can be The subject invention significantly lowers audible distor applied to active configurations.