Acoustical filtration method and apparatus for obtaining instrumental tones

Claim 2

An acoustical filtration method for obtaining instrumental tones having intricate selective frequency characteristics from a first set of electrical tone signals generated by a tone signal generator, comprising: converting said first set of signals into audible tones in an enclosure; directing and transmitting said audible tones within said enclosure into an acoustical horn featuring a plurality of selectable resonance frequencies and formed to have physical characteristics including a large cross sectional area at a mouth portion thereof and a narrow cross section of progressively decreasing area towards a throat region away from the mouth portion; selecting said plurality of resonance frequencies of said acoustical horn by varying the physical characteristics of the acoustical horn; converting such audible tones as are received by the horn within the enclosure into a second set or electrical signals by a microphonetransducer in the throat region; and rendering said second set of signals into acoustic output to obtain instrumental tones having intricate selective frequency characteristics.

Claim 3

A method as in claim 1 which includes a step of amplifying the first set of electrical tone signals prior to conversion thereof into audible tones in the enclosure.

Claim 4

A method as in claim 1 which includes a step of filtering said second set of electrical signals prior to said step of rendering the second set of signals into acoustic output.

Claim 5

A method as in claim 1 which includes the steps of diverting and passing a part of the first set of electrical tone signals through a tone-coloring circuit to obtain an auxiliary output, and mixing the auxiliary output with the second set of electrical signals resulting in instrumental tones having tone colored selective frequency characteristics.

Claim 6

An acoustical filtration apparatus for obtaining instrumental tones having intricate selective frequency characteristics from tone signals containing a large number of high frequency components generated by a tone signal generator, comprising: a first loud-speaker disposed in an enclosure and connected to receive tone signals from the tone signal generator and convert them into a first set of audible tones; an acoustical horn disposed facing said first loudspeaker in said enclosure and formed to have a large cross sectional area at a mouth portion thereof and a narrow cross section of progressively decreasing area towards a throat region away from the mouth portion, said acoustical horn having acoustical characteristics different from those of said first loudspeaker and featuring a plurality of selectable resonance frequencies; a microphone transducer disposed at said throat region for converting the plurality of selected resonance frequencies received thereby from the first loudspeaker into a second set of electrical signals, and a second loudspeaker for converting the second set of electrical signals into audible instrumental tone having intricate selected frequency characteristics.

Claim 7

An acoustical filtration apparatus for obtaining instrumental tones having intricate selective frequency characteristics from tone signals containing a large number of high frequency components generated by a tone signal generator, comprising: a first loud-speaker disposed in an enclosure and connected to receive tone signals from the tone signal generator and convert them into a first set of audible tones; an acoustical horn disposed facing said first loudspeaker in said enclosure and formed to have a large cross sectional area at a mouth portion thereof and a narrow cross section of progressively decreasing area towards a throat region away from the mouth portion, said acoustical horn having acoustical characteristics different from those of said first loudspeaker and featuring a plurality of selectable resonance frequencies; a microphone transducer disposed at said throat region for converting the plurality of selected resonance frequencies received thereby from the first loudspeaker into a second set of electrical signals, and a second loudspeaker for converting the second set of electrical signals into audible instrumental tone having intricate selected frequency characteristics.

Claim 8

An acoustical filtration apparatus according to claim 5 in which a first amplifier is connected between the tone signal generator and the first loudspeaker to amplify the tone signals prior to their being rendered into the first set of audible tones, and a second amplifier is connected between the microphone transducer and the second loudspeaker to amplify the second set of electrical signals prior to their being rendered into the audible instrumental tones.

Claim 9

An acoustical filtration apparatus according to claim 6 in which a tone-color circuit is connected between a junction point of the tone generator and the first amplifier and the junction point of the microphone transducer and the second amplifier thereby to mix an output of the toNe-color circuit with the second set of electrical signals.

Claim 10

An acoustical filtration apparatus according to claim 5 in which an electrical filter is connected to the output side of the microphone transducer to accomplish electrical filtration of the second set of electrical signals prior to their being converted into the audible instrument tones.

Claim 11

An acoustical filtration apparatus as in claim 5 which includes means to alter said plurality of selectable frequencies so as to obtain required resonance frequencies.