# US 8,787,596 B2 · Audio system including multiband audio dynamics processor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,596 B2 - Document ID: US8787596B2 - Status: Granted - Kind: B2 - Application number: 14/038,816 - Filed: 2013-09-27 - Published: 2014-01-23 - Granted: 2014-07-22 - Earliest claimed: 2008-12-17 - Assignees: Panasonic Automotive Systems Company of America, Division of Panasonic Corporation of North America - Applicants: Panasonic Automotive Systems Company of America, Division of Panasonic Corporation of North America - Inventors: Larry V. Craig; Michael T. Burke - Web page: https://patentgrep.com/patent/US8787596B2 ## CPC - H03G 9/18: for tone control and volume expansion or compression - H03G 3/20: Automatic control ({H03G3/005 takes precedence;} combined with volume compression or expansion H03G7/00) - H03G: CONTROL OF AMPLIFICATION ## Abstract An audio system includes a level controller receiving an input audio signal from an audio medium. The level controller includes a gain adjust module producing an output audio signal based on the input audio signal. A filter arrangement is communicatively coupled to the level controller. The filter arrangement receives the output audio signal and divides the output signal into a plurality of filtered signals. Each of the filtered signals corresponds to a respective frequency band. A multiband dynamics controller is communicatively coupled to the filter arrangement. The multiband dynamics controller receives the filtered signals and applies a respective gain characteristic to each of the filtered signals to thereby produce a plurality of gain adjust signals. The gain adjust signals are combined into a multiband dynamics controller output signal. ## Claims ### Claim 1 An audio system, comprising: an automatic level controller configured to receive at least one input audio signal from at least one audio medium, said automatic level controller including a gain adjust module configured to produce an output audio signal based on the at least one input audio signal, a difference between a maximum sound level and a minimum sound level of the at least one input audio signal being greater than a difference between a maximum sound level and a minimum sound level of the output audio signal; a filter arrangement communicatively coupled to the automatic level controller, the filter arrangement being configured to receive the output audio signal and divide the output signal into a plurality of filtered signals, each of the filtered signals corresponding to a respective frequency band; and a multiband dynamics controller communicatively coupled to the filter arrangement, the multiband dynamics controller being configured to: receive the filtered signals and apply a different respective gain characteristic to each of the filtered signals to thereby produce a plurality of gain adjust signals; and combine the gain adjust signals into a multiband dynamics controller output signal. ### Claim 2 (depends on 1) The audio system of claim 1 wherein each of the gain characteristics is a function of a level of the respective filtered signal. ### Claim 3 (depends on 1) The audio system of claim 1 further comprising a threshold detector module communicatively coupled to the gain adjust module and configured to determine whether the output audio signal is below a predetermined threshold value. ### Claim 4 (depends on 3) The audio system of claim 3 wherein the multiband dynamics controller is configured to receive a signal from the threshold detector module and adjust at least one of the gain adjust signals based upon the signal from the threshold detector module. ### Claim 5 (depends on 1) The audio system of claim 1 wherein each of the frequency bands corresponds to a predominant frequency of a selected type of musical instrument. ### Claim 6 (depends on 1) The audio system of claim 1 wherein the multiband dynamics controller includes a pullback module configured to receive at least one of the gain adjust signals and provide feedback to reduce at least one of the gain adjust signals if the received gain adjust signal exceeds a threshold value. ### Claim 7 (depends on 1) The audio system of claim 1 wherein the filter arrangement comprises a plurality of lowpass filters, a plurality of inverters, and a plurality of adders. ### Claim 8 An audio system, comprising: an automatic level controller configured to receive at least one input audio signal from at least one audio medium, said automatic level controller including a gain adjust module configured to produce an output audio signal based on the at least one input audio signal, a difference between a maximum sound level and a minimum sound level of the at least one input audio signal being greater than a difference between a maximum sound level and a minimum sound level of the output audio signal; a filter arrangement communicatively coupled to the automatic level controller, the filter arrangement being configured to receive the output audio signal and divide the output signal into a plurality of filtered signals, each of the filtered signals corresponding to a respective frequency band; and a multiband dynamics controller communicatively coupled to the filter arrangement, the multiband dynamics controller being configured to receive the filtered signals and apply a different respective gain characteristic to each of the filtered signals to thereby produce a plurality of gain adjust signals, wherein the automatic level controller is further configured to hold respective values of the gain characteristics substantially constant. ### Claim 9 (depends on 8) The audio system of claim 8 wherein the multiband dynamics controller is configured to combine the gain adjust signals into a multiband dynamics controller output signal. ### Claim 10 (depends on 8) The audio system of claim 8 wherein each of the gain characteristics is a function of a level of the respective filtered signal. ### Claim 11 (depends on 8) The audio system of claim 8 further comprising a threshold detector module communicatively coupled to the gain adjust module and configured to determine whether the output audio signal is below a predetermined threshold value, and wherein the multiband dynamics controller is configured to receive a signal from the threshold detector module and adjust at least one of the gain adjust signals based upon the signal from the threshold detector module. ### Claim 12 (depends on 8) The audio system of claim 8 wherein each of the frequency bands corresponds to a predominant frequency of a selected type of musical instrument. ### Claim 13 (depends on 8) The audio system of claim 8 wherein the multiband dynamics controller includes a pullback module configured to receive at least one of the gain adjust signals and provide feedback to reduce at least one of the gain adjust signals if the received gain adjust signal exceeds a threshold value. ### Claim 14 (depends on 8) The audio system of claim 8 wherein the filter arrangement comprises a plurality of lowpass filters, a plurality of inverters, and a plurality of adders. ### Claim 15 (depends on 8) The audio system of claim 8 wherein the automatic level controller is configured to hold respective values of the gain characteristics substantially constant until the output audio signal rises above a threshold value. ### Claim 16 An audio system, comprising: an automatic level controller configured to receive at least one input audio signal from at least one audio medium, said automatic level controller including: a gain adjust module configured to produce an output audio signal based on the at least one input audio signal; and a threshold detector module communicatively coupled to the gain adjust module and configured to receive the output audio signal and transmit a gate control signal in response to the output audio signal falling below a threshold value; a filter arrangement communicatively coupled to the automatic level controller, the filter arrangement being configured to receive the output audio signal and produce a plurality of filtered signals based on output audio signal; and a multiband dynamics controller communicatively coupled to the filter arrangement, the multiband dynamics controller being configured to: receive the filtered signals and apply a respective gain characteristic to each of the filtered signals to thereby produce a plurality of gain adjust signals; and receive the gate control signal and limit at least one of the gain adjust signals to a maximum value in response to receiving the gate control signal. ### Claim 17 (depends on 16) The audio system of claim 16 wherein each of the gain characteristics is a function of a level of the respective filtered signal. ### Claim 18 (depends on 16) The audio system of claim 16 further comprising a threshold detector module communicatively coupled to the gain adjust module and configured to determine whether the output audio signal is below a predetermined threshold value, and wherein the multiband dynamics controller is configured to receive a signal from the threshold detector module and adjust at least one of the gain adjust signals based upon the signal from the threshold detector module. ### Claim 19 (depends on 16) The audio system of claim 16 wherein each of the filtered signals corresponds to a respective frequency band, and each of the frequency bands corresponds to a predominant frequency of a selected type of musical instrument. ### Claim 20 (depends on 16) The audio system of claim 16 wherein the multiband dynamics controller includes a pullback module configured to receive at least one of the gain adjust signals and provide feedback to reduce at least one of the gain adjust signals if the received gain adjust signal exceeds a threshold value.