PATENT CLAIM ANALYSIS

Application Number: 15997375
Application Type: Utility
Filing Date: 2018-06
Publication Date: 2019-05
Patent Classification: ["381", "098000"]

Abstract:
A filter for correcting phase distortion produced at low frequencies in a loudspeaker system is created by inverting the phase response of the determined complex-valued frequency response of a loudspeaker system. The inverted phase response is obtained by taking the complex conjugate of the phase response. The impulse response for the inverted phase response is obtained by means of an inverse Fourier transform of the inverted phase response. The impulse response provides a linear phase FIR filter having a long filter length. The linear phase FIR filter is applied to the audio signal input to the loudspeaker system. Prior to inverting the phase response, the determined complex-valued frequency response of a loudspeaker system can be subjected to high frequency blanking and polynomial smoothing. Also, the linear phase FIR filter can be subjected to a window function prior to applying the filter to the audio signal.

Claim (Index 13):
A method of creating digital filter for correcting phase distortion produced at low frequencies in a loudspeaker system having a transducer driven by a piston with mass, comprising:\n a, obtaining the complex-valued frequency response of the loudspeaker system, said frequency response including a magnitude component (the magnitude response) and a phase component (the phase response), and having a number of data points for producing a relatively high resolution representation of the frequency response of the loudspeaker system, b. inverting the phase response obtained in step (a) by taking the complex conjugate of the phase response to produce an inverted phase response, c. obtaining the impulse response for the inverted phase response by means of an inverse Fourier transform of the inverted phase response, wherein said impulse response is a FIR filter having a long filter length that depends on a love frequency cut-off that is selected and is characterized by a series of FIR coefficients, d. applying a symmetric window function to the symmetric linear phase FIR filter to force the FIR coefficients to decay to zero by the end of the FIR filter length, e. adding pre-correction to the windowed symmetric linear phase FIR filter to correct for magnitude attenuation introduced by step (d) at low frequencies, and f. applying the pre-corrected windowed FIR filter to the audio signal input to the loudspeaker system for which the frequency response was obtained in step (a).

Metadata:
- Claim Count in Document: 26.0
- Percentile: 94.0
- Lexical Diversity: 2.44444
- Patent Class: 381.0
- Transitional Phrase Type: open
- Component Type: 1
- Foreign Priority: False
- Related Applications: ['14525898', '12825866', '10434448', '12293062', '13145758']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.6958182514541726
- 35 USC 102 Novelty (BERT): 0.5659196259128264
- Combined Prediction Score: 0.682828388900038
- Mean Citation Score: 284.079092
- Max Citation Score: 443.46036
- Similarity Product: 417.7185272384691

Labels:
- Claim Label 101: 1
- Claim Label 102: 1
- Claim Label 103: 1
- Claim Label 112: 0
- Combined Label: 1
- Label 101 Adjusted: 1

Dataset: test