WO2002007308A2 - Infrabass - Google Patents

Infrabass Download PDF

Info

Publication number
WO2002007308A2
WO2002007308A2 PCT/EP2001/007564 EP0107564W WO0207308A2 WO 2002007308 A2 WO2002007308 A2 WO 2002007308A2 EP 0107564 W EP0107564 W EP 0107564W WO 0207308 A2 WO0207308 A2 WO 0207308A2
Authority
WO
WIPO (PCT)
Prior art keywords
signal
input
bandwidth extension
extension device
delay
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP2001/007564
Other languages
French (fr)
Other versions
WO2002007308A3 (en
Inventor
Stefan M. J. Willems
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips Electronics NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Koninklijke Philips Electronics NV filed Critical Koninklijke Philips Electronics NV
Priority to JP2002513089A priority Critical patent/JP2004504642A/en
Priority to KR1020027003315A priority patent/KR20020031186A/en
Priority to EP01957911A priority patent/EP1258169A2/en
Publication of WO2002007308A2 publication Critical patent/WO2002007308A2/en
Publication of WO2002007308A3 publication Critical patent/WO2002007308A3/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/10009—Improvement or modification of read or write signals
    • G11B20/10046—Improvement or modification of read or write signals filtering or equalising, e.g. setting the tap weights of an FIR filter
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G5/00—Tone control or bandwidth control in amplifiers
    • H03G5/16—Automatic control
    • H03G5/165—Equalizers; Volume or gain control in limited frequency bands
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/10009—Improvement or modification of read or write signals
    • G11B20/10018—Improvement or modification of read or write signals analog processing for digital recording or reproduction

Definitions

  • the invention relates to a bandwidth extension device.
  • the invention further relates to an audio reproduction system comprising such a bandwidth extension device.
  • a sub- harmonics generator is used to create this low-pitched signal. In this way a lower pitch signal is created than is present in the incoming signal.
  • a first aspect of the invention provide a bandwidth extension device as defined in claim 1.
  • a second aspect of the invention is to provide an audio reproduction system.
  • the invention is based on the inside that during the creation of the sub- harmonics that part of the signal is delayed longer than the non-processed part of the signal.
  • Fig. 1 an example of a bandwidth extension device according to the invention
  • Fig. 2 an example of an audio reproduction system according to the invention.
  • Fig. 1 shows an example of a bandwidth extension device BD according to the invention.
  • a bandwidth extension device can be used in an audio reproduction system to improve the aural sensation of the low-pitched signal-part.
  • the device receives a left input signal and at a second input IR the bandwidth extension device receives a right input signal. Both inputs are coupled to a summing device SUM for a summing the both input signals in this example.
  • the output of the summing device is coupled to a band-pass filter BPF1 for filtering the summed input signal to a certain predetermined low frequency part.
  • the output of the band-pass filter BPF1 is coupled to a non-linear device NLD for creating an adapted signal with a low frequency part.
  • NLD non-linear device
  • the output of the non-linear NLD is coupled to a second band-pass filter BPF2 for filtering out the non-required frequency part.
  • the output of the band-pass filter BPF2 is coupled to a first combining device COMl and to a second combining device COM2.
  • the first combining device COMl receives at a second input a signal from an all-pass filter APF1 which all-pass filter is coupled with its input to the first input of the bandwidth extension device IL.
  • the second combining device COM2 receives a the other input a signal from a second all- pass filter APF2 which receives at its input a signal from the second input IR of the bandwidth extension device.
  • the output of the first and second combining device COMl respectively COM2 are coupled to the first and second output of the bandwidth extension device OL respectively OR.
  • the all-pass filters is also possible to use a delay element. Further it is possible to use a controllable delay element which makes it possible to amend the delay in dependence of the delay of the signal path through the band-pass filter BPFl, the non-linear device NLD and the band-pass filter BPF2.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
  • Amplitude Modulation (AREA)
  • Filters That Use Time-Delay Elements (AREA)

Abstract

To improve the aural sensation of audio signals the use of bandwidth extension devices in audio reproduction systems is known.Herewith it is possible to add a low-pitched signal to the audio signal comprising lower signal part than the original input signal.The invention provides an improvement of the known devices to overcome artifacts in the reproduced audio signal by delaying the unprocessed signal part to obtain the same delay as the obtained sub-harmonics.

Description

Infrabass
The invention relates to a bandwidth extension device. The invention further relates to an audio reproduction system comprising such a bandwidth extension device.
Such a device is known from the European patent application EP-A-0 240 286.
To improve the aural sensation in low-pitched (this is: signals in the very low frequency band) sound reproduction by an audio reproduction system or the like a sub- harmonics generator is used to create this low-pitched signal. In this way a lower pitch signal is created than is present in the incoming signal.
It is an object of the invention to improve such a bandwidth extension device further.
To this end a first aspect of the invention provide a bandwidth extension device as defined in claim 1. A second aspect of the invention is to provide an audio reproduction system.
The invention is based on the inside that during the creation of the sub- harmonics that part of the signal is delayed longer than the non-processed part of the signal. By combining these two signal parts in the combining means prior art devices have consequently artifacts. By delaying the non-processed signal part it is possible to delay both signal parts equal so overcoming the artifacts the prior art device has.
Embodiments of the invention are described in the dependent claims.
The invention and additional features, which may optimally be used to implement the invention to advantage, will be apparent from and elucidated with a reference to the examples described below and hereinafter and shown in the figures. Herein shows:
Fig. 1, an example of a bandwidth extension device according to the invention, and Fig. 2 an example of an audio reproduction system according to the invention.
Fig. 1 shows an example of a bandwidth extension device BD according to the invention. A bandwidth extension device can be used in an audio reproduction system to improve the aural sensation of the low-pitched signal-part.
At a first input IL the device receives a left input signal and at a second input IR the bandwidth extension device receives a right input signal. Both inputs are coupled to a summing device SUM for a summing the both input signals in this example. The output of the summing device is coupled to a band-pass filter BPF1 for filtering the summed input signal to a certain predetermined low frequency part. The output of the band-pass filter BPF1 is coupled to a non-linear device NLD for creating an adapted signal with a low frequency part. Herewith sub-harmonics of the lowest part of the input signal are created, resulting in a lower pitch signal than is present in the incoming signal.
Reference is made to the non-prepublished European application of the same applicant EP application ref. Nr. 00201509.7 (applicants ref. PHNL000249) wherein the use of sub- harmonics generators is described in detail.
The output of the non-linear NLD is coupled to a second band-pass filter BPF2 for filtering out the non-required frequency part.
The output of the band-pass filter BPF2 is coupled to a first combining device COMl and to a second combining device COM2.
The first combining device COMl receives at a second input a signal from an all-pass filter APF1 which all-pass filter is coupled with its input to the first input of the bandwidth extension device IL.
The second combining device COM2 receives a the other input a signal from a second all- pass filter APF2 which receives at its input a signal from the second input IR of the bandwidth extension device. The output of the first and second combining device COMl respectively COM2 are coupled to the first and second output of the bandwidth extension device OL respectively OR. By adding the all-pass filter APF1 and the all-pass filter APF2 having a certain delay it is made possible to combine in the combining devices the two signal parts with the same delay. This results in an improved output signal in comparison with prior art devices.
Instead of the all-pass filters is also possible to use a delay element. Further it is possible to use a controllable delay element which makes it possible to amend the delay in dependence of the delay of the signal path through the band-pass filter BPFl, the non-linear device NLD and the band-pass filter BPF2.

Claims

CLAIMS:
1. A band-pass extension device comprising an input for receiving an input signal, a first signal path and a second signal path whereby the first signal path comprises a filter means for filtering the input signal, creating means for creating an adapted signal with a lower frequency part than the input signal, combining means for combining the adapted signal of the first signal path with the input signal of the second signal path whereby the second signal path comprises between the input and the combining means delay means.
2. A bandwidth extension device as claimed in claim 1 , characterized in that the delay means comprise filter means.
3. A bandwidth extension device as claimed in claim 1, characterized in that the delay of the delay means is controllable.
4. An audio reproduction system comprising a bandwidth extension device as claimed in claim 1.
PCT/EP2001/007564 2000-07-13 2001-07-03 Infrabass Ceased WO2002007308A2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2002513089A JP2004504642A (en) 2000-07-13 2001-07-03 Infrastructure bus
KR1020027003315A KR20020031186A (en) 2000-07-13 2001-07-03 Infrabass
EP01957911A EP1258169A2 (en) 2000-07-13 2001-07-03 Infrabass

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP00202498.2 2000-07-13
EP00202498 2000-07-13

Publications (2)

Publication Number Publication Date
WO2002007308A2 true WO2002007308A2 (en) 2002-01-24
WO2002007308A3 WO2002007308A3 (en) 2002-09-12

Family

ID=8171799

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2001/007564 Ceased WO2002007308A2 (en) 2000-07-13 2001-07-03 Infrabass

Country Status (6)

Country Link
US (1) US20020015499A1 (en)
EP (1) EP1258169A2 (en)
JP (1) JP2004504642A (en)
KR (1) KR20020031186A (en)
CN (1) CN1451254A (en)
WO (1) WO2002007308A2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4480335B2 (en) * 2003-03-03 2010-06-16 パイオニア株式会社 Multi-channel audio signal processing circuit, processing program, and playback apparatus

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4769848A (en) * 1980-05-05 1988-09-06 Howard Krausse Electroacoustic network
DE3782959T2 (en) * 1986-04-01 1993-06-24 Matsushita Electric Ind Co Ltd LOW FREQUENCY TOEN GENERATOR.
US4982435A (en) * 1987-04-17 1991-01-01 Sanyo Electric Co., Ltd. Automatic loudness control circuit
JPH0454100A (en) * 1990-06-22 1992-02-21 Clarion Co Ltd Audio signal compensation circuit
DK168681B1 (en) * 1992-03-02 1994-05-16 Bang & Olufsen As Speaker with means for frequency dependent amplitude control
KR0139176B1 (en) * 1992-06-30 1998-06-15 김광호 Multiresolution Linear Distortion Compensation Method and Apparatus
JPH09261007A (en) * 1996-03-27 1997-10-03 Sony Corp Digital filter device
US5930373A (en) * 1997-04-04 1999-07-27 K.S. Waves Ltd. Method and system for enhancing quality of sound signal
KR100684054B1 (en) * 1998-09-08 2007-02-16 코닌클리케 필립스 일렉트로닉스 엔.브이. Bass enhancement means for audio systems
US6606388B1 (en) * 2000-02-17 2003-08-12 Arboretum Systems, Inc. Method and system for enhancing audio signals

Also Published As

Publication number Publication date
EP1258169A2 (en) 2002-11-20
US20020015499A1 (en) 2002-02-07
KR20020031186A (en) 2002-04-26
WO2002007308A3 (en) 2002-09-12
JP2004504642A (en) 2004-02-12
CN1451254A (en) 2003-10-22

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