GB1491663A - Equalizers - Google Patents
EqualizersInfo
- Publication number
- GB1491663A GB1491663A GB2368576A GB2368576A GB1491663A GB 1491663 A GB1491663 A GB 1491663A GB 2368576 A GB2368576 A GB 2368576A GB 2368576 A GB2368576 A GB 2368576A GB 1491663 A GB1491663 A GB 1491663A
- Authority
- GB
- United Kingdom
- Prior art keywords
- channels
- build
- gain
- delays
- dec
- 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.)
- Expired
Links
- 230000001934 delay Effects 0.000 abstract 2
- 230000003111 delayed effect Effects 0.000 abstract 1
- 230000005236 sound signal Effects 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers, loudspeakers or microphones
- H04R3/04—Circuits for transducers, loudspeakers or microphones for correcting frequency response
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G5/00—Tone control or bandwidth control in amplifiers
- H03G5/02—Manually-operated control
- H03G5/025—Equalizers; Volume or gain control in limited frequency bands
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
Abstract
1491663 Audio equalization system DOLBY LABORATORIES Inc 9 Dec 1974 [22 Dec 1973] 23685/76 Divided out of 1490970 Headings H4J and H4R In an audio equalization system, particularly for compensating for the change in effective frequency response of an audio system, due to the reverberative build-up of low frequencies in an auditorium, the signal is applied to a number of parallel channels, each of which includes a filter 50, to pass different frequency bands, a variable gain device 64, to provide control of the gain in the different channels, and a delay device 66, which delays the signals in the respective channels so that the channels having the greater gain are given a greater delay. The arrangement provides that the high frequencies are delayed so that they build up at the same rate as the low frequencies build up due to reverberation. To prevent discontinuities in the response characteristic due to phase differences at the edges of the pass bands of adjacent filters 50, the delays may be slowly reduced to zero after an "attack", or increase in level, in the sound signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2368576A GB1491663A (en) | 1973-12-22 | 1974-12-09 | Equalizers |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB59692/73A GB1490970A (en) | 1973-12-22 | 1973-12-22 | Equalizers |
| GB2368576A GB1491663A (en) | 1973-12-22 | 1974-12-09 | Equalizers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1491663A true GB1491663A (en) | 1977-11-09 |
Family
ID=26256670
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2368576A Expired GB1491663A (en) | 1973-12-22 | 1974-12-09 | Equalizers |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB1491663A (en) |
-
1974
- 1974-12-09 GB GB2368576A patent/GB1491663A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PE20 | Patent expired after termination of 20 years |
Effective date: 19941208 |