Overall Notes:
- Small rooms tend to have standing waves and cannot RFZs as well (room w/less than 20ms reflections).
- Splayed (angled) wall edges have to have greater angles - splays should be more than 12 degrees. Less than 5 is considered a graze.
- Reflections tend to reflect to absorption walls.
- Goal is to turn down volume by 10db. To achieve this you need an absorption co-efficient of 0.9 (90% absorption) or greater.
(Since DB= 10 log (.1) = -10 db)
- Speakers better flush mounted or standing (not in wall soffet): generally smother low end, no corner diffraction with better imaging.
- Rectangle rooms should not be "perfect" or will resonate certain notes.
Good ratios in musical format: 7/5, 8/5, 15/8, 7/4
Good rations in building format: 1 : 1.26 : 1.59 (1.6) - remember to think 3 dimensions.
( e.g.bobgolds.com mode calc. likes ratio 1:1.33 is 3/4 which is a perfect bad 4th. see - http://www.weslachot.com/articles_scales.html)
Good Wall Combos:
- 1/2" MDF + GG (GreenGlue) + 5/8" Drywall.
- 5/8" Drywall + GG + 5/8" Drywall
- Alternate drywall orientation. Wall board should be applied so last layer is horizontal (typically looks better).
Green Glue (GG):
Two separate unglued "leaves" are generally better than one thicker glued. An exception is:
http://greengluecompany.com/greenGlue-vs-ExtraDrywall.php
Panel Size /Weight /Lbs/SqFt /PCF /kG/M^3
4' x 8' x 3/8" = /45 lbs. /1.406 /42 /675
4' x 10' x 3/8" = /56 lbs. /1.406 /42 /675
4' x 12' x 3/8" = /67 lbs. /1.406 /42 /675
4' x 8' x 1/2" = /54 lbs. /1.6875 /42 /675
4' x 10' x 1/2" = /68 lbs. /1.6875 /42 /675
4' x 12' x 1/2" = /82 lbs. /1.6875 /42 /675
4' x 8' x 5/8" = /74 lbs. /2.3125 /42 /675
4' x 10' x 5/8" = /92 lbs. /2.3125 /42 /675
4' x 12' x 5/8" = /110 lbs. /2.3125 /42 /675
4' x 8' x 3/4" = /90 lbs. /2.81 /42 /675
Firecode Core Panels
4' x 8' x 5/8" = /70 lbs. /2.1875 /39.73 /638.5
4' x 10' x 5/8" = /88 lbs. /2.1875 /39.73 /638.5
4' x 12' x 5/8" = /105 lbs. /2.1875 /39.73 /638.5
Medium Density Hardboard – 43-60 PCF typical density, or 690-960 kG/m^3
To convert lb/cu ft into kG/m^3, multiply by 16.04. To convert the other way, divide by 16.04.
Concrete weights approx. 3600 lbs/cu yd when cured, about 3900 pounds wet.
133 lbs/cu ft, or 2133 kG/M^3 -
MDF - approx. 68 pounds per ½” 4x8 sheet or 2.125 PSF, 53 PCF, 850 kG/M^3
OSB - varies can be 700 kg/m3
Glass = approx. 3.8 times weight per unit thickness of sheet rock - roughly 161 lbs for 4x8 sheet of 3/8” glass.
The surface density of ¼” plywood is 0.74 lb/sq ft, or 23.68 pounds per 4’x8’ sheet.
The surface density of 3/8” plywood is 1.11 lb/sq ft, or 35.5 pounds per 4’x8’ sheet.
The surface density of ½” plywood is 1.48 lb/sq ft, or 47.36 pounds per 4’x8’ sheet.
The surface density of 5/8” plywood is 1.85 lb/sq ft, or 59.18 pounds per 4’x8’ sheet.
The surface density of ¾” plywood is 2.22 lb/sq ft, 71.04 pounds per 4’x8’ sheet, 35.5 PCF, 562.5 kG/M^3
A dry 8’ 2x4 weighs about 10 pounds, 2x6 about 15.7 pounds; density about 4.28 PSF for 2x lumber. This puts 2x lumber at roughly the same density as a layer of 5/8 and a layer of ½” drywall. 2x10 about 28 pounds per 8' length, or 3.5 lbs/lin.ft. –
2x10 framing on 24" centers adds approx. 2 lbs PSF dead load. 2x10 on 16" centers adds 2.7 PSF to dead load.
2x8 framing on 24" centers adds approx. 1.6 lbs PSF dead load. 2x8 on 16" centers adds 2.1 PSF to dead load.
2x6 framing on 24" centers adds approx. 1.2 lbs PSF dead load. 2x6 on 16" centers adds 1.6 PSF to dead load.
_____________________
0.00 = no absorbtion.
0.50 = 50% absorbtion.
1.00 = 100% absorbtion.
Owens Corning Fiberglass Batts Insulation
Product | thickness | mounting | 125hz | 250hz | 500hz | 1000hz | 2000hz | 4000hz | NRC |
Unfaced | 2.5" R8 | on wall | 0.21 | 0.62 | 0.93 | 0.92 | 0.91 | 1.03 | 0.85 |
Unfaced | 2.5" R8 | 16" air | 0.59 | 0.84 | 0.79 | 0.94 | 0.96 | 1.12 | 0.90 |
Unfaced | 3.5" R11 | on wall | 0.34 | 0.85 | 1.09 | 0.97 | 0.97 | 1.12 | 0.95 |
Unfaced | 3.5" R11 | 16" air | 0.80 | 0.98 | 1.01 | 1.04 | 0.98 | 1.15 | 1.00 |
Paper Out | 3.5" R11 | on wall | 0.58 | 1.11 | 1.16 | 0.61 | 0.40 | 0.21 | 0.80 |
Unfaced | 6.25" R19 | on wall | 0.64 | 1.14 | 1.09 | 0.99 | 1.00 | 1.21 | 1.05 |
Unfaced | 6.25" R19 | 16" air | 0.96 | 1.03 | 1.13 | 1.02 | 1.04 | 1.13 | 1.05 |
Paper Out | 6.25" R19 | on wall | 0.94 | 1.33 | 1.02 | 0.71 | 0.56 | 0.39 | 0.90 |
Unfaced | 12" | on wall | 1.14 | 1.09 | 1.09 | 0.99 | 1.00 | 1.21 |  |
(Owens Corning) OC 703 Panels
(2x4 x 4" x quantity 4 for $25.00)
4lbs/cu. ft. similar performance to rock wool down to about 50hz.
Product | thickness | mounting | density | 125hz | 250hz | 500hz | 1000hz | 2000hz | 4000hz | NRC |
701, plain | 1" (25mm) | on wall | 1.5 pcf (24 kg/m3) | 0.17 | 0.33 | 0.64 | 0.83 | 0.90 | 0.92 | 0.70 |
703, plain | 1" (25mm) | on wall | 3.0 pcf (48 kg/m3) | 0.11 | 0.28 | 0.68 | 0.90 | 0.93 | 0.96 | 0.70 |
705, plain | 1" (25mm) | on wall | 6.0 pcf (96 kg/m3) | 0.02 | 0.27 | 0.63 | 0.85 | 0.93 | 0.95 | 0.65 |
701, plain | 2" (51mm) | on wall | 1.5 pcf (24 kg/m3) | 0.22 | 0.67 | 0.98 | 1.02 | 0.98 | 1.00 | 0.90 |
703, plain | 2" (51mm) | on wall | 3.0 pcf (48 kg/m3) | 0.17 | 0.86 | 1.14 | 1.07 | 1.02 | 0.98 | 1.00 |
705, plain | 2" (51mm) | on wall | 6.0 pcf (96 kg/m3) | 0.16 | 0.71 | 1.02 | 1.01 | 0.99 | 0.99 | 0.95 |
701, plain | 3" (76mm) | on wall | 1.5 pcf (24 kg/m3) | 0.43 | 1.17 | 1.26 | 1.09 | 1.03 | 1.04 | 1.15 |
703, plain | 3" (76mm) | on wall | 3.0 pcf (48 kg/m3) | 0.53 | 1.19 | 1.21 | 1.08 | 1.01 | 1.04 | 1.10 |
705, plain | 3" (76mm) | on wall | 6.0 pcf (96 kg/m3) | 0.54 | 1.12 | 1.23 | 1.07 | 1.01 | 1.05 | 1.10 |
701, plain | 4" (102mm) | on wall | 1.5 pcf (24 kg/m3) | 0.73 | 1.29 | 1.22 | 1.06 | 1.00 | 0.97 | 1.15 |
703, plain | 4" (102mm) | on wall | 3.0 pcf (48 kg/m3) | 0.84 | 1.24 | 1.24 | 1.08 | 1.00 | 0.97 | 1.15 |
705, plain | 4" (102mm) | on wall | 6.0 pcf (96 kg/m3) | 0.75 | 1.19 | 1.17 | 1.05 | 0.97 | 0.98 | 1.10 |
703, plain | 6" (152mm) | on wall | 3.0 pcf (48 kg/m3) | 1.19 | 1.21 | 1.13 | 1.05 | 1.04 | 1.04 |  |
703, FRK | 1" (25mm) | on wall | 3.0 pcf (48 kg/m3) | 0.18 | 0.75 | 0.58 | 0.72 | 0.62 | 0.35 | 0.65 |
705, FRK | 1" (25mm) | on wall | 6.0 pcf (96 kg/m3) | 0.27 | 0.66 | 0.33 | 0.66 | 0.51 | 0.41 | 0.55 |
703, FRK | 2" (51mm) | on wall | 3.0 pcf (48 kg/m3) | 0.63 | 0.56 | 0.95 | 0.79 | 0.60 | 0.35 | 0.75 |
705, FRK | 2" (51mm) | on wall | 6.0 pcf (96 kg/m3) | 0.60 | 0.50 | 0.63 | 0.82 | 0.45 | 0.34 | 0.60 |
703, FRK | 3" (76mm) | on wall | 3.0 pcf (48 kg/m3) | 0.84 | 0.88 | 0.86 | 0.71 | 0.52 | 0.26 |  |
705, FRK | 3" (76mm) | on wall | 6.0 pcf (96 kg/m3) | 0.66 | 0.46 | 0.47 | 0.40 | 0.52 | 0.31 |  |
703, FRK | 4" (102mm) | on wall | 3.0 pcf (48 kg/m3) | 0.88 | 0.90 | 0.84 | 0.71 | 0.49 | 0.23 |  |
705, FRK | 4" (102mm) | on wall | 6.0 pcf (96 kg/m3) | 0.65 | 0.52 | 0.42 | 0.36 | 0.49 | 0.31 |  |
703, ASJ | 1" (25mm) | on wall | 3.0 pcf (48 kg/m3) | 0.17 | 0.71 | 0.59 | 0.68 | 0.54 | 0.30 | 0.65 |
705, ASJ | 1" (25mm) | on wall | 6.0 pcf (96 kg/m3) | 0.20 | 0.64 | 0.33 | 0.56 | 0.54 | 0.33 | 0.50 |
703, ASJ | 2" (51mm) | on wall | 3.0 pcf (48 kg/m3) | 0.47 | 0.62 | 1.01 | 0.81 | 0.51 | 0.32 | 0.75 |
705, ASJ | 2" (51mm) | on wall | 6.0 pcf (96 kg/m3) | 0.58 | 0.49 | 0.73 | 0.76 | 0.55 | 0.35 | 0.65 |
701, plain | 1" (25mm) | 16" air | 1.5 pcf (24 kg/m3) | 0.56 | 0.85 | 0.70 | 0.89 | 0.93 | 1.06 | 0.85 |
703, plain | 1" (25mm) | 16" air | 3.0 pcf (48 kg/m3) | 0.65 | 0.94 | 0.76 | 0.98 | 1.00 | 1.14 | 0.90 |
705, plain | 1" (25mm) | 16" air | 6.0 pcf (96 kg/m3) | 0.68 | 0.91 | 0.78 | 0.97 | 1.05 | 1.18 | 0.95 |
701, plain | 2" (51mm) | 16" air | 1.5 pcf (24 kg/m3) | 0.76 | 1.02 | 0.98 | 1.07 | 1.04 | 1.20 | 1.05 |
703, plain | 2" (51mm) | 16" air | 3.0 pcf (48 kg/m3) | 0.66 | 0.95 | 1.06 | 1.11 | 1.09 | 1.18 | 1.05 |
705, plain | 2" (51mm) | 16" air | 6.0 pcf (96 kg/m3) | 0.62 | 0.95 | 0.98 | 1.07 | 1.09 | 1.22 | 1.00 |
701, plain | 3" (76mm) | 16" air | 1.5 pcf (24 kg/m3) | 0.77 | 1.08 | 1.16 | 1.09 | 1.05 | 1.18 | 1.10 |
703, plain | 3" (76mm) | 16" air | 3.0 pcf (48 kg/m3) | 0.66 | 0.93 | 1.13 | 1.10 | 1.11 | 1.14 | 1.05 |
705, plain | 3" (76mm) | 16" air | 6.0 pcf (96 kg/m3) | 0.66 | 0.92 | 1.11 | 1.12 | 1.10 | 1.19 | 1.05 |
701, plain | 4" (102mm) | 16" air | 1.5 pcf (24 kg/m3) | 0.87 | 1.14 | 1.24 | 1.17 | 1.18 | 1.28 | 1.20 |
703, plain | 4" (102mm) | 16" air | 3.0 pcf (48 kg/m3) | 0.65 | 1.01 | 1.20 | 1.14 | 1.10 | 1.16 | 1.10 |
705, plain | 4" (102mm) | 16" air | 6.0 pcf (96 kg/m3) | 0.59 | 0.91 | 1.15 | 1.11 | 1.11 | 1.19 | 1.10 |
711, plain |  |  | 1.7 pcf |  |  |  |  |  |  |  |
1240 | 1.5" (38mm) | A | 4.0 pcf (64 kg/m3) | 0.13 | 0.48 | 1.02 | 1.08 | 1.02 | 1.01 | 0.90 |
1260 | 1.5" (38mm) | A | 6.0 pcf (96 kg/m3) | 0.18 | 0.62 | 1.08 | 1.08 | 1.03 | 1.07 | 0.95 |
1280 | 1.5" (38mm) | A | 8.0 pcf (96 kg/m3) | 0.13 | 0.64 | 1.08 | 1.08 | 1.04 | 1.07 | 0.95 |
1240 | 2" (51mm) | A | 4.0 pcf (64 kg/m3) | 0.20 | 0.61 | 1.07 | 1.06 | 1.04 | 1.07 | 0.95 |
1260 | 2" (51mm) | A | 6.0 pcf (96 kg/m3) | 0.25 | 0.85 | 1.15 | 1.10 | 1.04 | 1.06 | 1.05 |
1280 | 2" (51mm) | A | 8.0 pcf (96 kg/m3) | 0.32 | 0.90 | 1.11 | 1.07 | 1.01 | 1.05 | 1.00 |
1260 | 3" (76mm) | A | 6.0 pcf (96 kg/m3) | 0.80 | 1.07 | 1.11 | 0.99 | 0.98 | 0.96 | 1.05 |
1240 | 4" (102mm) | A | 4.0 pcf (64 kg/m3) | 0.88 | 1.14 | 1.17 | 1.08 | 1.06 | 1.10 | 1.10 |
1260 | 4" (102mm) | A | 6.0 pcf (96 kg/m3) | 0.99 | 1.01 | 1.10 | 1.03 | 1.03 | 1.05 | 1.05 |
1280 | 4" (102mm) | A | 8.0 pcf (96 kg/m3) | 1.11 | 0.91 | 1.07 | 1.03 | 1.06 | 1.07 | 1.00 |
1240 | 6" (152mm) | A | 4.0 pcf (64 kg/m3) | 1.31 | 1.14 | 1.11 | 1.09 | 1.06 | 1.07 | 1.10 |
Roxul Rigid Rockwool
Product | thickness | density | 125hz | 250hz | 500hz | 1000hz | 2000hz | 4000hz | NRC |
RXL 40 | 1" (25mm) | 7.4 pcf (118 kg/m3) | 0.07 | 0.32 | 0.77 | 1.04 | 1.05 | 1.05 | 0.80 |
RXL 60 | 1" (25mm) | 7.4 pcf (118 kg/m3) | 0.08 | 0.33 | 0.78 | 1.03 | 1.02 | 1.04 | 0.80 |
RXL 80 | 1" (25mm) | 8.0 pcf (128 kg/m3) | 0.11 | 0.31 | 0.82 | 1.01 | 1.02 | 1.01 | 0.80 |
AFB | 1" (25mm) | 3.0 pcf (48 kg/m3) | 0.14 | 0.25 | 0.65 | 0.90 | 1.01 | 1.01 | 0.70 |
RXL 40 | 1.5" (25mm) | 4.9 pcf (79 kg/m3) | 0.18 | 0.48 | 0.96 | 1.09 | 1.05 | 1.05 | 0.90 |
RXL 60 | 1.5" (25mm) | 6.0 pcf (96 kg/m3) | 0.17 | 0.62 | 1.00 | 1.05 | 1.01 | 1.01 | 0.90 |
RHF / RHT 80 | 1.5" (25mm) | 5.9 pcf (94 kg/m3) | 0.17 | 0.58 | 1.06 | 1.07 | 1.00 | 0.99 | 0.95 |
RXL 80 | 1.5" (25mm) | 8.0 pcf (128 kg/m3) | 0.21 | 0.64 | 0.92 | 1.00 | 0.95 | 1.01 | 0.90 |
AFB | 1.5" (33mm) | 3.0 pcf (48 kg/m3) | 0.18 | 0.44 | 0.94 | 1.04 | 1.02 | 1.03 | 0.85 |
RHT 40 | 1.5" (25mm) | 3.5 pcf (56 kg/m3) | 0.15 | 0.47 | 0.98 | 1.06 | 1.02 | 1.02 | 0.90 |
RHT 60 | 1.5" (25mm) | 4.4 pcf (70 kg/m3) | 0.19 | 0.55 | 1.03 | 1.06 | 1.02 | 1.01 | 0.90 |
RXL 40 | 2" (51mm) | 4.0 pcf (64 kg/m3) | 0.26 | 0.68 | 1.12 | 1.10 | 1.03 | 1.04 | 1.00 |
RXL 60 | 2" (51mm) | 6.0 pcf (96 kg/m3) | 0.32 | 0.81 | 1.06 | 1.02 | 0.99 | 1.04 | 0.95 |
RHF / RHT 80 | 2" (51mm) | 5.9 pcf (94 kg/m3) | 0.39 | 0.84 | 1.08 | 1.01 | 1.02 | 1.01 | 1.00 |
RXL 80 | 2" (51mm) | 8.0 pcf (128 kg/m3) | 0.43 | 0.78 | 0.90 | 0.97 | 0.97 | 1.00 | 0.90 |
Safe | 2" (51mm) | 4.5 pcf (72 kg/m3) | 0.26 | 0.68 | 1.12 | 1.10 | 1.03 | 1.04 | 1.00 |
AFB | 2" (51mm) | 2.5 pcf (40 kg/m3) | 0.28 | 0.60 | 1.09 | 1.09 | 1.07 | 1.07 | 0.95 |
RHT 40 | 2" (51mm) | 3.5 pcf (56 kg/m3) | 0.26 | 0.68 | 1.14 | 1.13 | 1.06 | 1.07 | 1.00 |
RHT 60 | 2" (51mm) | 4.4 pcf (70 kg/m3) | 0.26 | 0.71 | 1.14 | 1.09 | 1.04 | 1.03 | 1.00 |
RXL 40 | 3" (75mm) | 4.0 pcf (64 kg/m3) | 0.63 | 0.95 | 1.14 | 1.01 | 1.03 | 1.04 | 1.05 |
RXL 60 | 3" (75mm) | 6.0 pcf (96 kg/m3) | 0.78 | 0.89 | 1.04 | 0.98 | 1.01 | 1.02 | 1.00 |
RHF / RHT 80 | 3" (75mm) | 5.9 pcf (94 kg/m3) | 0.68 | 0.92 | 1.08 | 1.03 | 1.03 | 1.03 | 1.10 |
RXL 80 | 3" (75mm) | 8.0 pcf (128 kg/m3) | 0.75 | 0.82 | 0.89 | 0.94 | 1.00 | 1.00 | 0.90 |
Safe�n�Sound | 3" (75mm) | 2.5 pcf (40 kg/m3) | 0.52 | 0.96 | 1.18 | 1.07 | 1.05 | 1.05 | 1.05 |
Safe | 3" (76mm) | 4.5 pcf (72 kg/m3) | 0.63 | 0.95 | 1.14 | 1.01 | 1.03 | 1.04 | 1.05 |
AFB | 3" (75mm) | 2.5 pcf (40 kg/m3) | 0.52 | 0.96 | 1.18 | 1.07 | 1.05 | 1.05 | 1.05 |
RHT 40 | 3" (75mm) | 3.5 pcf (56 kg/m3) | 0.62 | 1.03 | 1.20 | 1.10 | 1.08 | 1.10 | 1.10 |
RHT 60 | 3" (75mm) | 4.4 pcf (70 kg/m3) | 0.65 | 0.94 | 1.13 | 1.07 | 1.06 | 1.04 | 1.10 |
RXL 40 | 4" (100mm) | 4.0 pcf (64 kg/m3) | 1.03 | 1.07 | 1.12 | 1.04 | 1.07 | 1.08 | 1.10 |
RHF / RHT 80 | 4" (100mm) | 5.9 pcf (94 kg/m3) | 1.00 | 0.95 | 1.06 | 1.04 | 1.06 | 1.08 | 1.05 |
Safe | 4" (100mm) | 4.5 pcf (72 kg/m3) | 1.03 | 1.07 | 1.12 | 1.04 | 1.07 | 1.08 | 1.10 |
AFB | 4" (100mm) | 2.5 pcf (40 kg/m3) | 0.86 | 1.11 | 1.20 | 1.07 | 1.08 | 1.07 | 1.10 |
RHT 40 | 4" (100mm) | 3.5 pcf (56 kg/m3) | 1.07 | 1.01 | 1.07 | 1.06 | 1.07 | 1.16 | 1.05 |
RHT 60 | 4" (100mm) | 4.4 pcf (70 kg/m3) | 0.92 | 1.04 | 1.07 | 1.07 | 1.07 | 1.08 | 1.05 |
Bonded Logic Inc's UltraTouch Cotton
Product | thickness | density | mounting | 125hz | 250hz | 500hz | 1000hz | 2000hz | 4000hz | NRC |
R-13 | 3.5" (mm) |  | A | 0.95 | 1.30 | 1.19 | 1.08 | 1.02 | 1.00 | 1.15 |
R-19 | 5.5" (mm) |  | A | 0.97 | 1.37 | 1.23 | 1.05 | 1.00 | 1.01 | 1.15 |
Acoustical Surfaces Echo Eliminator Acoustical Tests (Cotton)
Product | thickness | density | mounting | 125hz | 250hz | 500hz | 1000hz | 2000hz | 4000hz | NRC |
Echo Eliminator (Cotton) | 1" | 3pcf | A | 0.08 | 0.31 | 0.79 | 1.01 | 1.00 | 0.99 | 0.80 |
Echo Eliminator (Cotton) | 2" | 3pcf | A | 0.35 | 0.94 | 1.32 | 1.22 | 1.06 | 1.03 | 1.15 |
Echo Eliminator (Cotton) | 1" | 6pcf | A | 0.07 | 0.30 | 0.86 | 1.10 | 1.05 | 1.03 | 0.85 |
Bass Buster (Cotton) | 4" | 1.2pcf |  | 0.97 | 1.37 | 1.23 | 1.05 | 1.00 | 1.01 | 1.15 |
Cheap Sound Panel Mounts:
Use rubber door stops.
Table Data from:
http://www.johnlsayers.com/phpBB2/viewtopic.php?p=51414
http://www.bobgolds.com/AbsorptionCoefficients.htm
Example room:

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