First, thanks for the excellent write-up thumbsup
I followed your link to determine room modes (
http://www.bobgolds.com/Mode/RoomModes.htm) and frankly I could not understand the result:
Quote:
Frequency hz Spacing % Wavelength 1/2 Wavelength 1/4 Wavelength p q r Mode
36.5 9.44 4.72 2.36 1 0 0 Axial
37.7 3.1 9.14 4.57 2.28 0 1 0 Axial
52.5 28.1 6.56 3.28 1.64 1 1 0 Tangential
53.3 1.5 6.46 3.23 1.62 0 0 1 Axial
64.6 17.4 5.33 2.67 1.33 1 0 1 Tangential
65.3 1 5.27 2.64 1.32 0 1 1 Tangential
73.0 10.5 4.72 2.36 1.18 2 0 0 Axial
74.8 2.4 4.6 2.3 1.15 1 1 1 Oblique
75.4 0.7 4.57 2.28 1.14 0 2 0 Axial
82.1 8.1 4.2 2.1 1.05 2 1 0 Tangential
83.7 1.9 4.11 2.06 1.03 1 2 0 Tangential
90.4 7.4 3.81 1.9 0.95 2 0 1 Tangential
92.3 2 3.73 1.87 0.93 0 2 1 Tangential
97.9 5.7 3.52 1.76 0.88 2 1 1 Oblique
99.3 1.4 3.47 1.73 0.87 1 2 1 Oblique
104.9 5.3 3.28 1.64 0.82 2 2 0 Tangential
106.6 1.5 3.23 1.62 0.81 0 0 2 Axial
109.5 2.6 3.15 1.57 0.79 3 0 0 Axial
112.7 2.8 3.06 1.53 0.76 1 0 2 Tangential
113.0 0.2 3.05 1.52 0.76 0 3 0 Axial
113.1 0 3.05 1.52 0.76 0 1 2 Tangential
115.8 2.3 2.97 1.49 0.74 3 1 0 Tangential
117.7 1.6 2.93 1.46 0.73 2 2 1 Oblique
118.8 0.9 2.9 1.45 0.72 1 1 2 Oblique
118.8 0 2.9 1.45 0.72 1 3 0 Tangential
121.8 2.4 2.83 1.41 0.71 3 0 1 Tangential
125.0 2.5 2.76 1.38 0.69 0 3 1 Tangential
127.4 1.8 2.7 1.35 0.68 3 1 1 Oblique
129.2 1.3 2.67 1.33 0.67 2 0 2 Tangential
130.2 0.7 2.65 1.32 0.66 1 3 1 Oblique
130.6 0.3 2.64 1.32 0.66 0 2 2 Tangential
132.9 1.7 2.59 1.3 0.65 3 2 0 Tangential
134.6 1.2 2.56 1.28 0.64 2 1 2 Oblique
134.6 0 2.56 1.28 0.64 2 3 0 Tangential
135.6 0.7 2.54 1.27 0.64 1 2 2 Oblique
143.2 5.3 2.41 1.2 0.6 3 2 1 Oblique
144.7 1 2.38 1.19 0.6 2 3 1 Oblique
145.9 0.8 2.36 1.18 0.59 4 0 0 Axial
149.6 2.4 2.3 1.15 0.58 2 2 2 Oblique
150.7 0.7 2.29 1.14 0.57 0 4 0 Axial
150.7 0 2.29 1.14 0.57 4 1 0 Tangential
152.8 1.3 2.25 1.13 0.56 3 0 2 Tangential
155.1 1.4 2.22 1.11 0.56 1 4 0 Tangential
155.4 0.1 2.22 1.11 0.55 0 3 2 Tangential
155.4 0 2.22 1.11 0.55 4 0 1 Tangential
157.4 1.2 2.19 1.09 0.55 3 1 2 Oblique
157.4 0 2.19 1.09 0.55 3 3 0 Tangential
159.6 1.3 2.16 1.08 0.54 1 3 2 Oblique
159.9 0.1 2.15 1.08 0.54 0 0 3 Axial
159.9 0 2.15 1.08 0.54 0 4 1 Tangential
159.9 0 2.15 1.08 0.54 4 1 1 Oblique
164.0 2.4 2.1 1.05 0.53 1 4 1 Oblique
164.1 0 2.1 1.05 0.52 1 0 3 Tangential
164.3 0.1 2.1 1.05 0.52 0 1 3 Tangential
164.3 0 2.1 1.05 0.52 4 2 0 Tangential
166.1 1 2.07 1.04 0.52 3 3 1 Oblique
167.5 0.8 2.06 1.03 0.51 2 4 0 Tangential
168.3 0.4 2.05 1.02 0.51 1 1 3 Oblique
170.4 1.2 2.02 1.01 0.51 3 2 2 Oblique
171.7 0.7 2.01 1 0.5 2 3 2 Oblique
172.7 0.5 1.99 1 0.5 4 2 1 Oblique
175.7 1.7 1.96 0.98 0.49 2 4 1 Oblique
175.8 0 1.96 0.98 0.49 2 0 3 Tangential
176.8 0.5 1.95 0.97 0.49 0 2 3 Tangential
179.8 1.6 1.92 0.96 0.48 2 1 3 Oblique
180.5 0.3 1.91 0.95 0.48 1 2 3 Oblique
180.7 0.1 1.91 0.95 0.48 4 0 2 Tangential
182.4 0.9 1.89 0.94 0.47 5 0 0 Axial
184.6 1.1 1.87 0.93 0.47 0 4 2 Tangential
184.6 0 1.87 0.93 0.47 4 1 2 Oblique
184.6 0 1.87 0.93 0.47 4 3 0 Tangential
186.3 0.9 1.85 0.92 0.46 3 4 0 Tangential
186.3 0 1.85 0.92 0.46 5 1 0 Tangential
188.2 1 1.83 0.92 0.46 1 4 2 Oblique
188.4 0.1 1.83 0.91 0.46 0 5 0 Axial
Computed Information:
Room Dimensions: Length=4.72 m, Width=4.57 m, Height=3.23 m
Room Ratio: 1 : 1.41 : 1.46
R. Walker BBC 1996:
- 1.1w / h < l / h < ((4.5w / h) - 4): Fail
- l < 3h & w < 3h: Pass
- no integer multiple within 5%: Fail (ratio3 = ratio2 * 1)
Nearest Known Ratio:
- "3) L. W. Sepmeyer: 1965" 1 : 1.28 : 1.54
RT60 (IEC/AEC N 12-A standard): 246 ms
- ±50ms from 200Hz to 3.5kHz = 196 to 296ms
- ±100ms above 3.5kHz = 146 to 346ms
- <+300ms at 63hz = 546ms
- 300<RT60<600ms
RT60 (ITU/EBU Control Room Recommended): 220 ms
- ±50ms from 200Hz to 4kHz = 170 to 270ms
- <+300ms at 63hz = 520ms
- 200<RT60<400ms
Absorbtion to achieve ITU RT60: 545 sabins
Volume: 69 m^3
Surface Area Total: 100 m^2
Surface Area Floor: 21 m^2
Surface Area Ceiling+Floor: 42 m^2
Surface Area Front Wall: 14 m^2
Surface Area Front and Rear Wall: 28 m^2
Surface Area Left Wall: 15 m^2
Surface Area Left and Right Wall: 30 m^2
Surface Area 4 Walls: 58 m^2
Surface Area 4 Walls + floor: 79 m^2
(sabins - front wall - carpet) / Left+Right+Rear wall: 35 %
(sabins - front wall) / Left+Right+Rear wall: 83 %
Schroeder Fc: 106hz
Frequency Regions:
- No modal boost: 1hz to 36hz
- Room Modes dominate: 36hz to 106hz
- Diffraction and Diffusion dominate: 106hz to 424hz
- Specular reflections and ray accoustics prevail: 424hz to 20000hz
Count (36.4-189hz) : Axials=13, Tangentials=55, Obliques=75
Count (36.4-100hz) : Axials=5, Tangentials=7, Obliques=3
Critical Distance (direct = reverberant field): 4.60m
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Does this tell me anything about how to properly treat it or where to place the speakers (5.1) or where to sit? Or is this just nice to know and measuring is the only way to determine all of the above?
Thanks