Churches as auditoria: analysis of
acoustical parameters for a better
understanding of sound quality
Paola Ricciardi
Department of Civil Engineering and
Architecture, University of Pavia,
Via Ferrata, 1 - 27100 Pavia, Italy
Tel: +39 0382 985303e-mail:
[email protected]
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
The research
The acoustic characterisation of buildings for music
performances:
Worship buildings can be used as auditoriums?
Theoretical models and software
Experimental measurements
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
The aim and the results
A contribution to the data collection on the acoustic
performance of the Churches aimed to their use as
auditorium
Deeper knowledge on the influence of the internal
geometric complexities on the acoustic field, such as:
lateral chapels,
coupled rooms,
diffusive elements or obstacles to the sound
propagation,
orientation of surfaces,
convex surfaces than can create sound
concentration
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
The Churches
10 Churches - rectangular plan (nave – 2 aisles)
with/without lateral chapels and/or cupolas,
volume = 2183 - 43540 m3
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
The Churches
14 Churches: central plan
with/without dome/cupolas
volume = 1409 - 43756 m3
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
The Churches
Southern France
6 Medieval Cistercian Abbeys
volume = 3390 - 14970 m3
The 3 Provençal
Sisters
Northern Italy
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
MEASUREMENTS – longitudinal plan
Measured data in 10 Italian churches
(XI-XVI sec., V=220043.000 m3)
Church
S.Lorenzo
SS.Annunziata
S.M.Castello
N.S.Consolazione
S.Agostino
S.M.Vigne
S.Donato
S.Matteo
S.Siro di Struppa
SS.Cosma e
Damiano
Points V [m 3] S [m 2]
C50
[dB]
C80
[dB]
D50
[%]
EDT RT20 RT30
[s]
[s]
[s]
TS
[ms]
17
27
26
15
24
18
21
12
11
43540
26603
21100
18842
14500
14000
4650
3211
3827
2040
1815
1755
1065
1223
1308
340
338
383
-9.2
-8.8
-9.8
-10.2
-8.9
-8.5
-7.6
-6.5
-7.4
-6.7
-6.5
-6.5
-7.7
-5.2
-5.8
-4.1
-3.3
-3.5
16.3
17.6
12.9
14.7
15.5
17.5
18.4
20.7
18.5
5.1
4.7
3.8
4.5
2.7
3.6
2.3
2.3
2.6
5.1
4.2
3.6
5.2
2.5
4.1
2.3
2.4
2.8
--3.6
4.6
2.3
3.6
2.4
2.5
2.8
387.1
362.8
308.2
368.9
227.8
296.2
193.2
185.1
202.0
12
2183
241
-6.3
-2.8
22.3
2.0
2.0
2.2
164.9
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
MEASUREMENTS – CENTRAL PLAN
Measured data in 10 Italian churches
(XI-XVI sec., V=250049.000 m3)
Church
S.Maria Assunta
S.Zita
Chiesa del Gesù
N.S.del Rimedio
S.Maria Immacolata
S.Caterina
S.Benedetto
S.Croce S.Camillo
S.Pietro in Banchi
S.Luca
Measur.
points
28
12
16
12
18
17
6
10
13
6
V
[m3]
49471
29220
25595
18040
16262
11650
4700
3955
2584
2494
Stot
[m2]
1837
1107
1580
731
860
905
307
269
189
140
C50
[dB]
-10.53
-11.67
-9.22
-9.19
-8.82
-10.15
-9.62
-8.11
-7.79
-8.44
C80
[dB]
-8.29
-9.54
-6.74
-7.21
-6.79
-6.81
-6.13
-5.59
-4.69
-6.24
D50
[%]
11.58
8.75
14.38
12.17
15.24
10.75
11.63
15.84
15.16
14.05
EDT RT20 RT30
[s]
[s]
[s]
6.12 6.16 5.61
8.79 8.77 8.90
3.97 3.86 3.05
5.60 6.19 6.20
4.89 4.95 4.46
3.73 3.69 3.69
3.13 3.17 3.21
3.21 3.21 3.22
2.80 2.83 2.87
3.77 4.00 4.07
TS
[ms]
467
666
314
411
365
297
257
252
224
290
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P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Reverberation Time at 500 Hz – Optimal values
10
RT [s]
8
6
4
Longitudinal Plan [1,2]
Central Plan [4]
Cistercian Abbeys [3]
Southern Italy [18]
Spain [14,15]
organ music
classical music
modern music
2
0
0
10000
20000
30000
40000
V
[m3]
50000
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Reverberation Time
9
……
RT [s]
6
3
Theatres
y = 0.19 x + 1.36
2
R = 0.50
Longitudinal Plan
Central Plan
Cistercian Abbeys
Southern Italy
Spain
Theatres
Regression line
0
5
10
15
20
25
V/S 30
[m]
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Clarity Index C80
0
C80
Longitudinal Plan
Central Plan
Cistercian Abbeys
Southern Italy
Spain
Lineare (Regression Line)
……
-2
-4
-6
-8
-10
y = -0.21x - 2.77
R2 = 0.40
-12
5
10
15
20
25 V/S 30
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
RT – Century of construction
10
Central Plan ……
Longitudinal Plan
Cistercian Abbeys
RT [s]
8
6
4
2
0
9
IX
12
XII
15
XV
18
XVIII
21
XXI
Century
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Mean RT
as
function
of SR
distance
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
C80 as
function
of SR
distance
4
Longitudinal Plan [1,2]
C80 [dB]
Central Plan [4]
Cistercian Abbeys [3]
0
-4
-8
-12
0
10
20
30
40
Source - Receiver Distance [m]
50
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60
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
D50 as
function
of SR
distance
70
D50 [%]
Longitudinal Plan [1,2]
Central Plan [4]
Cistercian Abbeys [3]
60
50
40
30
20
10
0
0
10
20
30
40
Source - Receiver Distance [m]
50
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60
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
CONSIDERATIONS
Worship buildings with more articulated volumes
(Gesù Church, with 7 cupolas) are more adequate
for music performances.
For this aim, almost all the central plan Churches
are not appropriate, unless some acoustic
corrections are realised.
The RT distribution for Churches with rectangular
plan and two aisles without cupolas was
significantly different from the ones with central
plans.
Among these last ones, bigger volume Churches
presented more scattered RT values.
And other
considerations….
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
CONSIDERATION ON THE HISTORICAL
PERIOD
In the French Cistercian Abbeys some acoustic features
may have been intentionally prosecuted by the Ancient
Architects
Average values
of RT in the range
500-1000 Hz
The values are
higher than in
other churches
with almost the
same volume
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
CONSIDERATION ON THE EFFECT OF THE
GEOMETRY ON RT
The RT under the dome is lower in larger volume churces,
but higher in smaller ones
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
CHARACTERISTICS OF THE CHURCH OF S. ZITA
• Construction of 1874
•Both domes are in
reinforced concrete
•Pavement in marble,
•Interior simply
painted
•On the pavement
•Wooden desk
Cupola grande
Tamburo cupola
Tot. Cupola grande
Lucernario
Cupola minore
Totale cupole
pavimento
Camera principale
TOTALE
Sup. connessione grande
Sup. connessione piccola
Sup. connessione totale
VOLUME
ALTEZZA
SUPERFICIE
(m3)
(m2)
(m)
3619
904
12.3
3850
620
7.7
7588
1649
20
119
125
10
710
320
9.5
30
8298
1969
1180
21600 (laterale) 2650
18.3
29898
6389
500
92
592
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
48.3
CHARACTERISTICS OF THE CHURCH OF S. GIORGIO
•The period of
construction is around
1695
•Pavement in marble,
•Interior higly decorated
Cupola
Tamburo cupola
Tot. Cupola
pavimento
Camera principale
TOTALE
Sup. connessione
•Sul pavimento panche di legno
AIA – Firenze 2007
VOLUME SUPERFICIE
(m3)
(m2)
540
280
1833
560
2373
3510
5885
840
300
1200
2500
141
ALTEZZA
(m)
5.8
13
18.8
11.7
30.5
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
TRIDIMENSIONAL MODELS FOR THE SIMULATION
S.Zita
S. Giorgio
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
SIMULATIONS RESULTS
4.275
8.58
8.56
8.54
8.52
8.5
8.48
8.46
8.44
8.42
8.4
8.38
8.36
8.34
8.32
8.3
8.28
8.26
8.24
8.22
8.2
8.18
8.16
4.27
4.265
4.26
4.255
4.25
4.245
4.24
4.235
4.23
4.225
4.22
4.215
4.21
4.205
4.2
4.195
4.19
SPATIAL DISTRIBUTION OF
TR20 IN THE FREQUENCY
RANGE 125 Hz – 4 kHz FOR
S. Zita
SPATIAL DISTRIBUTION OF TR20
IN THE FREQUENCY RANGE 125
Hz – 4 kHz FOR
S. Giorgio
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
VARIATION OF THE ABSORPTION
COEFFICIENT
12
3
Center
TR [s] 1000 Hz
11
10
4
4
5
11
1 12
1 5
88 6 6
2
10 9
7
1
1
9
8
Complex Model
no big dome
7
no small dome
no domes
6
5
no big dome absorption=1
no small dome absorption =1
Lateral to the source
no domes absorption=1
big dome absorption=1
4
1
2
3
4 5 6 7 8 9
Measurement points
10 11 12
Small dome absorption=1
both domes absorption=1
For both curches with domes having  >0.3 the minimum of RT disappear
with  >0.7 the minimum is reached in the positions near the dome,
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
CONSIDERATION ON THE MEASUREMENT
CAMPAIGN
Martellotta F., Cirillo E., Carbonari A., Ricciardi P.
(2009). Guidelines for acoustical measurements in
churches. Applied acoustics, vol. 70, p. 378-388.
• Churches are listening spaces that differ from concert halls
and theatres
• Differences are due to the coexistence of speech and music
being radiated from several positions that varied with the
evolving liturgy
• In addition the room complexity may induce different
research teams to place sources and receivers in a different
way reducing measurement comparability
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Aims of the proposal
• Define a group of standardised source
positions
• Define a minimum number and a rule to
place receivers
• Define the equipment characteristics as a
function of the measurement purpose
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Source placement
E
F
C
A 2.0
B
D
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Source placement
E
F
C
A 2.0
B
D
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Source placement
• A) Altar (reference)
position
• At 2 m distance
• On the symmetry axis
(provided that no focussing
effects may be detected)
• At 1.5 m from the floor
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Source placement
• B) High Altar position
E
• At 1 m distance from the
vertical surface
• On the symmetry axis
(provided that no focussing
effects may be detected)
• At 1.5 m from the basament
of the altar
C
A 2.0
B
D
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P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Source placement
• C) Ambos position
E
• Located at the symmetrical
position opposite the actual
ambos (to prevent
interference)
• or at 2 m from the edge of
the chancel
• At 1.5 m from the floor
C
A 2.0
B
D
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Source placement
• D) Choir position
E
• Located at the centre of the
C
A 2.0
B
D
area occupied by the singers
• or at the centre of the
wooden stalls
• in any case the source must
be at least 1 m far from
walls
• the height must be 1.5 m
from the floor
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Source placement
• E) Organ position
• Located close to the centre
of the organ pipes, at a
distance of 1 m
• If the span of the pipes is
larger than 6 m 2 positions
(E1 and E2) should be used
• If the centre of the pipes
cannot be reached the
source height must be 2 m
from the floor
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Source placement
• F) Pulpit position
• Located on the pulpit,
provided that it is easily
accessible
• The source height should be
at least 1.7 m and, in any
case overcame the
balustrade by at least 0.5 m
• The source directivity
should be close to human
voice
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Source placement
• G) Dome position
• Located 1 m off the axis of
the church
• 2m from the centre of the
dome
• 2 m within the projection of
the dome
• 1.5 m from the floor
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Receivers placement
Minimum 9 receivers
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Receivers placement
L/6
L
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P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Receivers placement
8
6
7
4
2
5
3
1
5b
3b
1b
9
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Receivers placement
13
10
11
9
9b
6
7
12
2
5
5b
3
1
14
1b
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Source and receiver combinations
Source
Receivers in the main volume
Receivers in secondary volumes
A, altar
All + 3 control rec.
All
50% + 2 control rec.
At least one in the same “volume”
where the source is located
F, pulpit
50% + 3 control rec.
None
G, dome
50%
At least 5 receivers under the
dome
H…Z, extra
50%
At least one in the same volume
where the source is located
B, high altar
C, ambos
D, choir
E, organ
WORSHIP SOUND PLACES- MUSÉE DU QUAI BRANLY, NOVEMBER 3-4, 2015 (PARIS)
P.Ricciardi - Churches as auditoria: analysis of acoustical parameters for a better understanding of sound quality
Measurement equipment
Sound source
Basic
Intermediate
Advanced
Rendering
Every source
complying with ISO
3382
Electro-acoustic
omni-directional
Electro acoustic,
omni-directional +
sub-woofer
Same as
Advanced, Lw>100
dB if V> 50000 m3
Deterministic
(MLS, sweep)
Deterministic
(MLS, sweep)
preferably
equalized
Same as
Advanced, but
constant amplitude
equalized sweep is
preferred
B-format + dummy
head
Noise, impulse,
deterministic
Signal
Microphones
Omni-directional
Omni + figure8
Omni+figure8 (or
B-format) + dummy
head
Freq. Range (Hz)
125-4000
125-4000
63-8000
63-16000
Sampling
44.1 kHz, 16 bit
44.1 kHz, 16 bit
44.1 kHz, 16 bit
48 kHz, 24 bit
Measurable
parameters
T30, EDT and, with
restrictions on the
source, C, D, Ts, G
T30, EDT, C, D,
Ts, G, LF, LG
T30, EDT, C, D,
Ts, G, LF, LG,
IACC
All
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