Digital crossover and parametric equalizer
AssigneeNew Japan Radio Co., Ltd.
InventorS. R. Prakash
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Abstract
A DSP-based and multi-channel digital filter chip providing crossover filtering and parametric equalization. Crossovers can be low-pass, high-pass, or band-pass filters with programmable cutoff frequencies. Each equalizer band has independently adjustable center frequency band, and levels over a −60 dB to +16 dB range. The chip can work either with a microprocessor controlling the chip or in a stand-alone mode having the filter settings downloaded automatically from an external EEPROM. The chip is ideal for applications that require precise digital filtering or software programmable filters, and is also an alternative to analog filters, eliminating passive components and reducing circuit size.
Claims7
A device having a multi-channel digital filter, comprising:
- a digital signal processor (DSP) for running said filter;
- an I/O interface coupled to said DSP for exchanging information with external devices;
- a first memory coupled to said DSP for use by said DSP;
- and
- a second memory coupled to said DSP
- for providing programs which implement filters by providing a desired filter from a prototype filter, and
- for providing filter design processes
- and thereby providing outputs for said filter;
- wherein coefficients for said prototype filters are represented using a pole.
A memory storing a program implementing filters embedded in a chip comprising:
- means for storing filter coefficients using a pole;
- and
- means for calculating filter coefficients using poles and zeros;
- wherein said program provides crossover filtering and parametric equalization.
Dependencies are inferred from the claim text.