Patent EA-002858-B1 (EA)
Title: Capacitor-less crossover network for electro-acoustic loudspeakers
Inventor: ALEXANDER ERIC
IPC: H04R3/14
Filed: 1998-10-02
Abstract: 1. In an audio system capacitor-less crossover network for partitioning by frequency an electrical audio signal as provided by at least one amplifier into at least one high frequency band and one low frequency band for powering a corresponding at least one high frequency electro-acoustic transducer and a low frequency electro-acoustic transducer, said capacitor-less crossover network comprising: (a) an input pair comprised of a positive input and a negative input as received from said at least one amplifier; (b) an inductor having a first input end electrically coupled to said positive input of said input pair and a second input end for coupling in shunt with at least one of said high frequency electro-acoustic transducer; and (c) a shunt resistor having a first end electrically coupled to said second input end of said inductor, and said second end of said shunt resistor electrically coupled to said negative input of said input pair and for coupling to a negative input of said low frequency electro-acoustic transducer, for reproducing low-frequency bands, said shunt resistor coupled parallel to said low frequency electro-acoustic transducer, 2. In an audio system, the capacitor-less crossover network, as recited in Claim 1, further comprising at least one first inductor for coupling in shunt with at least one mid-range frequency electro-acoustic transducer, each of at least one said first inductors coupled in series with others of said at least one inductors, said series of said at least one inductor having a first mid-range terminal end electrically coupled to said negative input end of said inductor and said series of at least one inductor also having a second mid-range terminal end for electrically coupling to a first input of said low frequency electro-acoustic transducer. 3. In an audio system, the capacitor-less crossover network, as recited in Claim 2, wherein said at least one inductor is comprised of one inductor for coupling in shunt with one mid-range frequency electro-acoustic transducer, said one inductor having a first end electrically coupled to said negative input end of said inductor and a second end for electrically coupling with said first input of said lower frequency electro-acoustic transducer. 4. In an audio system, the capacitor-less crossover network, as recited in Claim 3, comprising: (a) said inductor attached in shunt with high frequency electro-acoustic transducer having a value of approximately 0.25 milliHenries; (b) said inductor attached in shunt with mid frequency electro-acoustic transducer having a value of approximately 2 milliHenries; and (c) said shunt resistor having a value of approximately 10 ohms. 5. In an audio system, the capacitor-less crossover network, as recited in Claim 1, wherein said capacitor-less crossover network is compatible for inter-operating with said high frequency and said low frequency electro-acoustic transducers of a dynamic electro-magnet type. 6. In an audio system, the capacitor-less crossover network, as recited in Claim 1, wherein said capacitor-less crossover network is compatible for inter-operating with said high frequency electro-acoustic transducers of a piezoelectric type. 7. In an audio system, the capacitor-less crossover network, as recited in Claim 1, wherein said capacitor-less crossover network is compatible for inter-operating with said high frequency and said low frequency electro-acoustic transducers of an electrostatic type. 8. An audio system, comprising: (a) at least one high frequency electro-acoustic transducer; (b) a low frequency electro-acoustic transducer; and (c) a series-configured, capacitor-less crossover network for partitioning by frequency an electrical audio signal as provided by at least one amplifier into a plurality of frequency bands comprising at least one high frequency band and one low frequency band for driving a corresponding plurality of electro-acoustic transducers comprising said at least one high frequency driver and said low frequency driver, said capacitor-less crossover network comprising: (i) an input pair comprised of a positive input and a negative input as received from said at least one amplifier; (ii) an inductor having a first input end electrically coupled to said positive input of said input pair and a second input end for coupling in shunt with one of said at least one high frequency electro-acoustic transducer; and (iii) a shunt resistor having a first end electrically coupled to said second input end of said at least one inductor and a second end electrically coupled to said negative input of said input pair for coupling to a negative input of said low frequency band electro-acoustic transducer, said shunt resistor for coupling at least partially in shunt with said low frequency electro-acoustic transducer, said series-configured capacitor-less crossover network containing no discrete capacitors for partitioning said audio signals into said frequency bands. 9. The audio system, as recited in Claim 8, wherein said capacitor-less crossover network further comprises at least one inductor for coupling in shunt with at least one mid-range frequency electro-acoustic transducer, each of said at least one inductors coupled in a series with others of said at least one inductors, said series of said at least one inductor having a first terminal end electrically coupled to said negative input end of said inductor and said series of at least one inductor also having a terminal end for electrically coupling to a first input of said low frequency electro-acoustic transducer. 10. The audio system, as recited in Claim 9, wherein said at least one inductor of said capacitor-less crossover network is comprised of one inductor coupled in shunt with one mid-range frequency electro-acoustic transducer, said one inductor having a first end electrically coupled to said second input end of said inductor coupled in shunt with high frequency driver, and a second end for electrically coupling with said first input of said low frequency electro-acoustic transducer. 11. The audio system, as recited in Claim 10, wherein said capacitor-less crossover network is comprised of: (a) an inductor connected in shunt with high frequency electro-acoustic transducer said inductor having a value of approximately 0.25 milliHenries; (b) an inductor connected in shunt with mid-range frequency electro-acoustic transducer, said inductor having a value of approximately 2 milliHenries; and (c) said shunt resistor having a value of approximately 10 ohms. 12. The audio system, as recited in Claim 8, wherein said capacitor-less crossover network is compatible for inter-operating with said high frequency electro-acoustic transducers and said low frequency electro-acoustic transducers of an electro-magnetic dynamic type. 13. The audio system, as recited in Claim 8, wherein said capacitor-less crossover network is compatible for inter-operating with said high frequency electro-acoustic transducer of a piezoelectric type. 14. The audio system, as recited in Claim 8, wherein said capacitor-less crossover network is compatible for inter-operating with said high frequency and said low frequency electro-acoustic transducers of an electrostatic type. 15. In an audio system, a series-configured, capacitor-less crossover network for partitioning by frequency an electrical audio signal into a plurality of frequency bands comprising a high frequency band and a low frequency band to drive a high frequency driver and a low frequency driver, respectively, said capacitor-less crossover network comprising: (a) a positive input and a negative input forming an input pair for receiving said electrical audio signal an audio system amplifier; (b) an inductor connected in shunt with the high frequency driver, having a first input end electrically coupled to said positive input of said input pair, said inductor also having a second input end, said inductor for coupling in shunt with said high frequency driver via said first and second input ends; and a shunt resistor having a first end electrically coupled to said second input end of said inductor, said shunt resistor also having a second end electrically coupled to said negative input of said input pair, said shunt resistor for coupling in shunt with said low frequency driver via said first and second ends, said capacitor-less crossover network containing no discrete capacitors for partitioning said audio signals into said frequency bands. 16. In an audio system, the series-configured, capacitor-less crossover network, as recited in Claim 15, comprising: a) an inductor connected in shunt with high frequency driver, said inductor having a value of approximately 0.25 milliHenries; and b) said shunt resistor having a value of approximately 10 ohms. 17. In an audio system, a series-configured, capacitor-less crossover network for partitioning by frequency an electrical audio signal into a plurality of frequency bands comprising a high frequency band, a mid-range frequency band and a low frequency band to drive a high frequency driver, a mid-range frequency driver and a low frequency driver, respectively, said capacitor-less crossover network comprising: (a) a positive input and a negative input forming an input pair for receiving said electrical audio frequency signal from an audio system amplifier; (b) a first inductor having a first input end electrically coupled to said positive input of said input pair, said first inductor also having a second input end, said first inductor for coupling in shunt with said high frequency driver via said first and second input ends; (c) a second inductor coupled in series with said first inductor via a first input end electrically coupled to said second input end of said first inductor, said second inductor also having a first input end, said second inductor for coupling in shunt with said mid-range frequency driver via said first and second input ends; and (d) a shunt resist