CA1294893C - Device adjusting the sound pattern including the time of reverberation in a room - Google Patents
Device adjusting the sound pattern including the time of reverberation in a roomInfo
- Publication number
- CA1294893C CA1294893C CA000531600A CA531600A CA1294893C CA 1294893 C CA1294893 C CA 1294893C CA 000531600 A CA000531600 A CA 000531600A CA 531600 A CA531600 A CA 531600A CA 1294893 C CA1294893 C CA 1294893C
- Authority
- CA
- Canada
- Prior art keywords
- sound
- room
- reverberation
- time
- device adjusting
- 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
- 238000000034 method Methods 0.000 claims description 7
- 239000002245 particle Substances 0.000 abstract description 3
- 239000011358 absorbing material Substances 0.000 abstract 1
- 230000002745 absorbent Effects 0.000 description 18
- 239000002250 absorbent Substances 0.000 description 18
- 238000010521 absorption reaction Methods 0.000 description 11
- 239000000463 material Substances 0.000 description 6
- 230000010355 oscillation Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 230000003213 activating effect Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- ZYXYTGQFPZEUFX-UHFFFAOYSA-N benzpyrimoxan Chemical compound O1C(OCCC1)C=1C(=NC=NC=1)OCC1=CC=C(C=C1)C(F)(F)F ZYXYTGQFPZEUFX-UHFFFAOYSA-N 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000011010 flushing procedure Methods 0.000 description 1
- 239000011491 glass wool Substances 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
- E04B1/99—Room acoustics, i.e. forms of, or arrangements in, rooms for influencing or directing sound
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
- E04B1/62—Insulation or other protection; Elements or use of specified material therefor
- E04B1/74—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls
- E04B1/82—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls specifically with respect to sound only
- E04B2001/8263—Mounting of acoustical elements on supporting structure, e.g. framework or wall surface
- E04B2001/829—Flat elements mounted at an angle, e.g. right angle, to the supporting surface
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Acoustics & Sound (AREA)
- Electromagnetism (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Building Environments (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
ABSTRACT
A DEVICE ADJUSTING THE SOUND PATTERN INCLUD-ING THE TINE OF REVERBERATION IN A ROOM
A device adjusting the sound pattern including the time of reverberation in a room and comprising a plurality of sound-absorbing/reflecting members mountable in the corners of the room. Each sound-absorbing member is shaped in such a manner that it is preferably situated in positions adjacent a corner where the velocity of the air particles is particularly high. In this manner a good utilization of the sound-absorbing material is obtained. Furthermore a uniform frequency response is obtained, and the possibili-ties of adjusting the time of reverberation are improved.
Fig. 5d should be published together with the abstract.
A DEVICE ADJUSTING THE SOUND PATTERN INCLUD-ING THE TINE OF REVERBERATION IN A ROOM
A device adjusting the sound pattern including the time of reverberation in a room and comprising a plurality of sound-absorbing/reflecting members mountable in the corners of the room. Each sound-absorbing member is shaped in such a manner that it is preferably situated in positions adjacent a corner where the velocity of the air particles is particularly high. In this manner a good utilization of the sound-absorbing material is obtained. Furthermore a uniform frequency response is obtained, and the possibili-ties of adjusting the time of reverberation are improved.
Fig. 5d should be published together with the abstract.
Description
The invention relates to a method of adjusting the sound field in a room including the time of reverberation by means of sound-absorbing members mountable in the corners of the room.
Swedish Patent Application No. 8103345 discloses the use of planar diagonal absorbents adjusting the sound pattern including the time of reverberation in a room. The frequency response is, however, not completely satisfactory as it is not sufficiently uniform, cf. Fig. 5_.
The invention is characterized by determining the areas in the corners by measurings where the sound field is particularly strong, subsequently adapting the sound-absorbing members in such a manner that they extend through said areas.
In this manner a uniform frequency response is obtained and consequently the possibilities of adjustiny the time of reverberation are improved. Furthermore the members accordiny to the invention are flexible in such a manner that architectural solutions have become possihle.
The invention will be described below with reference .~ .
~r~
.
~4~3 to the accompanying drawings, in which Fig. 1 illustrates a kl~own diagonal absorbent to be situated in a corner, Fig- 2 illustrates Ekin/Epot of a diffuse sound field in a corner, Fig. 3 illustrates isoabsorption curves (Ekin/Epot con-stant) with diagonal absorbents therein and with different ratios of size to wave length, Fig. 4 illustrates the absorp~ion versus the frequency, Fig. 5 illustrates the absorption versus the frequency with differing embodiments of the absorbent, and Fig. 6 illustrates the flow resistance versus the density.
At frequencies exceedin~ about 100 - 300 Hz the sound absorption takes place in th~ diagonal absorbent of Fig. 1 during the ~ovement of the air particles in a porous immov-able material. The absorbent is situated in a corner where the veloclties of the air particles, cf. Fig. 2, are high.
The frequency fl where the absorption is maximum can be deter~ined based on theoretical anal~ses of the sound field in a corner, as f 140 _ 280 Hz ~ d Q- sin?~
where d is the depth of the absorbent in meters whereas Q
and 9 are indicated in Fig. 1.
At lower frequencies (50 - 200 H~) and with diagonal absorbents where ~ is less than 2 m the sound absorption occurs substantially by the sheet material being made 09cil-lating at the resonance frequency and by the energy being absorbed as a consequence of loss in the material and loss along the rims where the ~aterial is secured. ~hen activat-ing these resonance oscillations the areas of the sound field including high pressure vsriations are of importance.
'. 35 In connection with a planar diagonal absorbent of a low bending resistance compared to the resistance of the con-fined air the resonance frequency is:
, .
~2~ 93 ~o = ~120 ~z where m i9 the mass of the sheet material per area unit in kg/m2 and Q is the length in meter. The first-mentioned process at high frequencies involves specific requirements 5 as to size, shape, and flow resistance. The second process at low frequencies involves specific requirements as to the size and mass per area unit.
The highest possible sound absorption is aimed at in the frequency interval 100 - 4000 Hz, and the absorption 10 should preferably take place as uniEorm as possible in this frequency interval.
Experiments with planar diagonal absorbents have given - promlsing results when Q ~ 0.90 m and ~ ~ 30, and still better results can be expected in connection with particu-15 lar, not planar embodiments, cf. Fig. 5 d. Conversely uneven frequency processes are to be expected at particularly disadvantageous embodiments. Problem~ arise at low frequen-cies if the dimensions are too small. Furthermore the ob-tainable absorption area depends on the surface area of 20 the absorbent.
As the resonance frequency fO should be about 100 Hz, and ~ is a~sumed- to be in the area of 0.90 - 1.80 m, the following requirements to the mass per area unit appear:
m 1 - 2 kg/m2 as the mass per area unit must be highest for small values of Q . Experiments have shown that the flow resistance should be somewhat higher than concerning traditionally suspended ceiling plates, probably about: r - 2000 - 2500 30 Ns/m3. These values depend on the thickness of the plate h as well as on actual material parameters according to the formula:
m ~ p _, where p is the density, and r ~ L, where ~ is the specific flow resistance.
.
Z~L8~3 Thus ~ ~ 1.250 s 1 p is obtained, which can be recorded in a ~-p^diagramm as a line, cf. Fig. 6. The latter may indicate that the optimum 5 fibre diameter is somewhat smaller than the fibre diameter of usual glass wool. As an alternative a coating suitably increasing the flow resistance can be used.
In order to avoid high frequency signals from being reflected from a too strongly compressed surface the specif-lO ic flow resistance should not be too high. The materialparameters should be selected within the following inter-vals:
h p ~
15 20 mm 100 kg/m3 125-103 Ns/m4 40 mm 50 kg/m3 63-103 Ns/m4 Figs. 5a - e show the characteristics of differing embodiments of the absorption member. Fig. 5a show~ an oval absorption member providing a very uneven frequency 20 response as said frequency response discloses a notch at 0.7 corresponding to the absorption material being situated in positions with the weakest oscillations. The diagonal absorbent of Fig. 5b provides also a very poor response as in any case only part of the absorbent is si-~5 tuated at the spot disclosing highest oscillations. A minor improvement is obtained by situating the diagonal absorbent asymmetrically with an angle differing from 45. F~. 3 illustrates the effect of such an absorbent on the sound field at different frequencies. It appears that ~he re-30sponse must necessarily show a notch (illustrated at about 500 Hz). Fig. 5d illustrates an ideal embodiment of the absorption member, said member being situated in areas including a~particularly strong sound field. Fig. 5e illu--- strates the abeorption member of an alternative asymmetric embodiment, i.e. an asymmetrically I.-shaped embodiment.
Fig. 6 illustrates the flow resistances versus the density of various types of msterial.
The sound-absorbing members can optionally be altered 5 in response to one or more parameter values in the room, optionally in such a manner that they counteract a possible alteration of the parameter values in question.
The sound-absorbing members can for instance be used in a concert hall and be adJusted in response to the parti-lOcular requirements of an orchestra concerning the time ofreverberation etc. optlonally durin~ a concert.
The absorbents are situated either in one or more corners of the room or along the xim of the ceiling. The absorbent of F~g. Se is preferably situated along the rim 15 of the ceiling optionally in connection with a perforated sound-permeable under-ceiling flushing with the absorbent and providing a good architectural effect.
' :
'.
. -
Swedish Patent Application No. 8103345 discloses the use of planar diagonal absorbents adjusting the sound pattern including the time of reverberation in a room. The frequency response is, however, not completely satisfactory as it is not sufficiently uniform, cf. Fig. 5_.
The invention is characterized by determining the areas in the corners by measurings where the sound field is particularly strong, subsequently adapting the sound-absorbing members in such a manner that they extend through said areas.
In this manner a uniform frequency response is obtained and consequently the possibilities of adjustiny the time of reverberation are improved. Furthermore the members accordiny to the invention are flexible in such a manner that architectural solutions have become possihle.
The invention will be described below with reference .~ .
~r~
.
~4~3 to the accompanying drawings, in which Fig. 1 illustrates a kl~own diagonal absorbent to be situated in a corner, Fig- 2 illustrates Ekin/Epot of a diffuse sound field in a corner, Fig. 3 illustrates isoabsorption curves (Ekin/Epot con-stant) with diagonal absorbents therein and with different ratios of size to wave length, Fig. 4 illustrates the absorp~ion versus the frequency, Fig. 5 illustrates the absorption versus the frequency with differing embodiments of the absorbent, and Fig. 6 illustrates the flow resistance versus the density.
At frequencies exceedin~ about 100 - 300 Hz the sound absorption takes place in th~ diagonal absorbent of Fig. 1 during the ~ovement of the air particles in a porous immov-able material. The absorbent is situated in a corner where the veloclties of the air particles, cf. Fig. 2, are high.
The frequency fl where the absorption is maximum can be deter~ined based on theoretical anal~ses of the sound field in a corner, as f 140 _ 280 Hz ~ d Q- sin?~
where d is the depth of the absorbent in meters whereas Q
and 9 are indicated in Fig. 1.
At lower frequencies (50 - 200 H~) and with diagonal absorbents where ~ is less than 2 m the sound absorption occurs substantially by the sheet material being made 09cil-lating at the resonance frequency and by the energy being absorbed as a consequence of loss in the material and loss along the rims where the ~aterial is secured. ~hen activat-ing these resonance oscillations the areas of the sound field including high pressure vsriations are of importance.
'. 35 In connection with a planar diagonal absorbent of a low bending resistance compared to the resistance of the con-fined air the resonance frequency is:
, .
~2~ 93 ~o = ~120 ~z where m i9 the mass of the sheet material per area unit in kg/m2 and Q is the length in meter. The first-mentioned process at high frequencies involves specific requirements 5 as to size, shape, and flow resistance. The second process at low frequencies involves specific requirements as to the size and mass per area unit.
The highest possible sound absorption is aimed at in the frequency interval 100 - 4000 Hz, and the absorption 10 should preferably take place as uniEorm as possible in this frequency interval.
Experiments with planar diagonal absorbents have given - promlsing results when Q ~ 0.90 m and ~ ~ 30, and still better results can be expected in connection with particu-15 lar, not planar embodiments, cf. Fig. 5 d. Conversely uneven frequency processes are to be expected at particularly disadvantageous embodiments. Problem~ arise at low frequen-cies if the dimensions are too small. Furthermore the ob-tainable absorption area depends on the surface area of 20 the absorbent.
As the resonance frequency fO should be about 100 Hz, and ~ is a~sumed- to be in the area of 0.90 - 1.80 m, the following requirements to the mass per area unit appear:
m 1 - 2 kg/m2 as the mass per area unit must be highest for small values of Q . Experiments have shown that the flow resistance should be somewhat higher than concerning traditionally suspended ceiling plates, probably about: r - 2000 - 2500 30 Ns/m3. These values depend on the thickness of the plate h as well as on actual material parameters according to the formula:
m ~ p _, where p is the density, and r ~ L, where ~ is the specific flow resistance.
.
Z~L8~3 Thus ~ ~ 1.250 s 1 p is obtained, which can be recorded in a ~-p^diagramm as a line, cf. Fig. 6. The latter may indicate that the optimum 5 fibre diameter is somewhat smaller than the fibre diameter of usual glass wool. As an alternative a coating suitably increasing the flow resistance can be used.
In order to avoid high frequency signals from being reflected from a too strongly compressed surface the specif-lO ic flow resistance should not be too high. The materialparameters should be selected within the following inter-vals:
h p ~
15 20 mm 100 kg/m3 125-103 Ns/m4 40 mm 50 kg/m3 63-103 Ns/m4 Figs. 5a - e show the characteristics of differing embodiments of the absorption member. Fig. 5a show~ an oval absorption member providing a very uneven frequency 20 response as said frequency response discloses a notch at 0.7 corresponding to the absorption material being situated in positions with the weakest oscillations. The diagonal absorbent of Fig. 5b provides also a very poor response as in any case only part of the absorbent is si-~5 tuated at the spot disclosing highest oscillations. A minor improvement is obtained by situating the diagonal absorbent asymmetrically with an angle differing from 45. F~. 3 illustrates the effect of such an absorbent on the sound field at different frequencies. It appears that ~he re-30sponse must necessarily show a notch (illustrated at about 500 Hz). Fig. 5d illustrates an ideal embodiment of the absorption member, said member being situated in areas including a~particularly strong sound field. Fig. 5e illu--- strates the abeorption member of an alternative asymmetric embodiment, i.e. an asymmetrically I.-shaped embodiment.
Fig. 6 illustrates the flow resistances versus the density of various types of msterial.
The sound-absorbing members can optionally be altered 5 in response to one or more parameter values in the room, optionally in such a manner that they counteract a possible alteration of the parameter values in question.
The sound-absorbing members can for instance be used in a concert hall and be adJusted in response to the parti-lOcular requirements of an orchestra concerning the time ofreverberation etc. optlonally durin~ a concert.
The absorbents are situated either in one or more corners of the room or along the xim of the ceiling. The absorbent of F~g. Se is preferably situated along the rim 15 of the ceiling optionally in connection with a perforated sound-permeable under-ceiling flushing with the absorbent and providing a good architectural effect.
' :
'.
. -
Claims (3)
1. A method of adjusting the sound field in a room including the time of reverberation by means of sound-absorbing members mountable in the corners of the room, characterized by determining the areas in the corners by measurings where the sound field is particularly strong, subsequently adapting the sound-absorbing members in such a manner that they extend through said areas.
2. A method as claimed in claim 1 comprising changing the angle of the sound-absorbing members with respect to the walls or ceiling of the room.
3. A method as claimed in claim 1 comprising deforming the sound-absorbing members.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DK112186A DK157819C (en) | 1986-03-11 | 1986-03-11 | PROCEDURE FOR REGULATING THE SOUNDFIELD IN A LOCATION |
| DK1121/86 | 1986-03-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1294893C true CA1294893C (en) | 1992-01-28 |
Family
ID=8101249
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000531600A Expired CA1294893C (en) | 1986-03-11 | 1987-03-10 | Device adjusting the sound pattern including the time of reverberation in a room |
Country Status (17)
| Country | Link |
|---|---|
| JP (1) | JPS63113322A (en) |
| BE (1) | BE1000032A7 (en) |
| CA (1) | CA1294893C (en) |
| CH (1) | CH674043A5 (en) |
| DE (1) | DE3705438A1 (en) |
| DK (1) | DK157819C (en) |
| ES (1) | ES2002991A6 (en) |
| FI (1) | FI83117C (en) |
| FR (1) | FR2595856A1 (en) |
| GB (1) | GB2188186B (en) |
| GR (1) | GR870367B (en) |
| IE (1) | IE59607B1 (en) |
| IT (1) | IT1202617B (en) |
| NL (1) | NL8700513A (en) |
| NO (1) | NO870806L (en) |
| PT (1) | PT84453B (en) |
| SE (1) | SE8700983L (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2281539A (en) * | 1993-09-01 | 1995-03-08 | Torrington Co | Adjustable vehicle steering column assembly |
| WO2003002955A1 (en) * | 2001-06-28 | 2003-01-09 | Kkdk A/S | Method and system for modification of an acoustic environment |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB375726A (en) * | 1931-01-28 | 1932-06-30 | Marconi Wireless Telegraph Co | Improvements in or relating to acoustic adjusting apparatus for use in sound studiosand the like |
| GB496384A (en) * | 1936-03-26 | 1938-11-25 | Waldemar Oelsner | Improved means for controlling the acoustic properties of rooms |
| SE427364B (en) * | 1980-04-09 | 1983-03-28 | A & K Byggnadsfysik Ab | DIAGONALLY MOUNTED SOUND ABSORBENT |
-
1986
- 1986-03-11 DK DK112186A patent/DK157819C/en not_active IP Right Cessation
-
1987
- 1987-02-20 DE DE19873705438 patent/DE3705438A1/en not_active Withdrawn
- 1987-02-26 NO NO870806A patent/NO870806L/en unknown
- 1987-03-03 NL NL8700513A patent/NL8700513A/en not_active Application Discontinuation
- 1987-03-03 IT IT19558/87A patent/IT1202617B/en active
- 1987-03-05 GR GR870367A patent/GR870367B/en unknown
- 1987-03-06 FR FR8703086A patent/FR2595856A1/en active Pending
- 1987-03-06 ES ES8700626A patent/ES2002991A6/en not_active Expired
- 1987-03-06 CH CH845/87A patent/CH674043A5/de not_active IP Right Cessation
- 1987-03-09 FI FI871014A patent/FI83117C/en not_active IP Right Cessation
- 1987-03-10 GB GB8705590A patent/GB2188186B/en not_active Expired - Fee Related
- 1987-03-10 CA CA000531600A patent/CA1294893C/en not_active Expired
- 1987-03-10 SE SE8700983A patent/SE8700983L/en not_active Application Discontinuation
- 1987-03-10 IE IE60387A patent/IE59607B1/en not_active IP Right Cessation
- 1987-03-10 JP JP62053195A patent/JPS63113322A/en active Pending
- 1987-03-11 BE BE8700239A patent/BE1000032A7/en not_active IP Right Cessation
- 1987-03-11 PT PT84453A patent/PT84453B/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| PT84453A (en) | 1987-04-01 |
| IE870603L (en) | 1987-09-11 |
| FI871014A0 (en) | 1987-03-09 |
| DK157819C (en) | 1990-09-10 |
| DK112186D0 (en) | 1986-03-11 |
| GB8705590D0 (en) | 1987-04-15 |
| JPS63113322A (en) | 1988-05-18 |
| IE59607B1 (en) | 1994-03-09 |
| BE1000032A7 (en) | 1987-11-24 |
| SE8700983D0 (en) | 1987-03-10 |
| GB2188186B (en) | 1990-02-14 |
| DK157819B (en) | 1990-02-19 |
| GB2188186A (en) | 1987-09-23 |
| NO870806D0 (en) | 1987-02-26 |
| NO870806L (en) | 1987-09-14 |
| FI83117C (en) | 1991-05-27 |
| IT1202617B (en) | 1989-02-09 |
| FI871014A (en) | 1987-09-12 |
| PT84453B (en) | 1989-10-04 |
| GR870367B (en) | 1987-07-10 |
| ES2002991A6 (en) | 1988-10-01 |
| SE8700983L (en) | 1987-09-12 |
| IT8719558A0 (en) | 1987-03-03 |
| NL8700513A (en) | 1987-10-01 |
| CH674043A5 (en) | 1990-04-30 |
| DK112186A (en) | 1987-09-12 |
| FR2595856A1 (en) | 1987-09-18 |
| DE3705438A1 (en) | 1987-09-17 |
| FI83117B (en) | 1991-02-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |