Circuits for improved audio signal reconstruction

• US 9,247,340 B2
• Filed: 10/01/2014
• Issued: 01/26/2016
• Est. Priority Date: 05/15/2013
• Status: Active Grant

• Current Assignee: REVx Technologies, Inc.
• Original Assignee: REVx Technologies, Inc.
• Inventors: Powell, Wayne J., Rauschmayer, Dennis
• Primary Examiner(s): Mei, Xu
• Assistant Examiner(s): SUTHERS, DOUGLAS JOHN
• Application Number:
  US14/503,687
• Publication Number:
  US 20150016634A1
• Time in Patent Office: 482 Days
• Field of Search: 381/59, 381/58, 381/55, 381/111, 381/123
• US Class Current: 1/1
• CPC Class Codes: H03H 2001/005 Wound, ring or feed-through type inductor
• CPC Class Codes: H03H 7/1783 Combined LC in series path
• CPC Class Codes: H03H 7/20 Two-port phase shifters providing an adjustable phase shift
• CPC Class Codes: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H04R 1/26 Spatial arrangements of separate transducers responsive to two or more frequency ranges
• CPC Class Codes: H04R 2400/00 Loudspeakers
• CPC Class Codes: H04R 3/00 Circuits for transducers , loudspeakers or microphones

Abstract

An impedance matched resonant circuit uses inductors coupling an audio source and a speaker array in order to reduce feedback reflection induced by an audio signal traveling from the audio source to the array of speakers. An RC circuit could also be coupled to the positive and negative terminals of the speaker array to reduce the slope differential of the audio signal at certain frequencies. The circuit can be packaged together in a single module with switches to activate and deactivate portions of the circuit to alter the effectiveness of the circuit depending upon need.

Claims

1. A circuit configured to reduce quantization noise in an audio signal reconstructed from digitally encoded audio, comprising:

a first circuitry comprising a first inductor in series with a capacitor, both of which are in parallel with a second inductor, wherein the first circuitry is configured to be coupled to a positive terminal of an audio signal source and to a positive terminal of an array of speakers; and

a second circuitry comprising a third inductor, wherein the second circuitry is configured to be coupled to a negative terminal of the audio signal source and to a negative terminal of the array of speakers,

wherein the first inductor, the second inductor, the capacitor, and the third inductor are selected such that a Thevenin equivalent impedance of the first circuitry approximately matches the impedance of the second circuitry.

2. The circuit of claim 1, wherein at least one of the first, second, and third inductors comprises a paramagnetic material.

3. The circuit of claim 1, wherein at least one of the first, second, and third inductors comprise a ferromagnetic material.

4. The circuit of claim 1, wherein at least one of the first, second, and third inductors has a gap that comprises at least one of a ferromagnetic and a diamagnetic material.

5. The circuit of claim 1, wherein a first switch is in parallel with the first circuitry.

6. The circuit of claim 1, wherein a second switch is in parallel with the second circuitry.

7. The circuit of claim 1, wherein the Thevenin equivalent impedance of the first circuitry and the impedance of the second circuitry are within 15% of one another.

8. The circuit of claim 1, wherein the capacitor is a variable capacitor.

9. The circuit of claim 8, wherein the variable capacitor is varied mechanically.

10. The circuit of claim 8, wherein the variable capacitor is varied electronically.

11. The circuit of claim 8, wherein at least one of the first inductor, the second inductor, and the third inductor is a variable inductor.

12. The circuit of claim 11, wherein the variable inductor is varied mechanically.

13. The circuit of claim 11, wherein the variable inductor is varied electronically.