Fire Rated Acoustic Doors University of Minnesota - Northrop Auditorium University of Minnesota - Northrop Auditorium
Doors up to 65 Feet x 65 Feet
Sound Isolation to STC 60
Custom Engineered Doors
Sliding Doors Without Floor Track

A Guide to the Meaning of Sound Levels

Sound Level
dB (A)
Type of NoiseNoise Level Effect
0 Threshold of hearing inaudible
20 Rural Environment Extremely quiet
25 Bedroom Quiet house
40 Living room Distant sounds audible
50 Background conversation Moderate
60 Normal conversation Moderate to loud
85 Average street Traffic loud
100 Pneumatic road drill (very loud) Very loud
110 Pop group deafening Deafening
125 Jet take-off 100m distance Deafening
140 Jet engine 25m distance Threshold of pain
Sound Transmission Class Examples

STC Sound
What can be heard
25 Normal speech can be understood quite easily through wall
30 Loud speech can be understood fairly well, normal speech heard but not understood
35 Loud speech audible but not intelligible
40 Onset of 'privacy'
42 Loud speech audible as a murmur
45 Loud speech not audible; 90% of statistical population not annoyed
50 Very loud sounds such as musical instruments of stereo can be faintly heard; 99% of population not annoyes
60+ Superior soundproofing; most sounds inaudible
Door Capabilites

Door type Max. attenuation -STC
Single leaf swing - Pedestrian STC50
Double leaf swing - Pedestrian STC49
Single/Double swing (High Spec)  STC55/57
Single leaf swing - Oversized STC56
Double leaf swing - Oversized STC53
Single horizontal sliding STC60
Double horizontal sliding STC53
Single vertical sliding STC56
Double vertical sliding STC53
Triple vertical sliding STC50
Tandem doorsets STC75

N.B. The final performance of any door solution will be subject to the detailed design decisions made, we would be happy to provide early advice.