The IGH Building Physics Laboratory has conducted Laboratory testing on SST Tube Bass Trap units type D35 in the echo chamber.
The test procedure includes the echo chamber in which is placed 10 Tube Bass Trap Absorbers, each 1.06 meters high, 0.35 meters in diameter.
Total Absorption sample surface is S = 11.3 m2.
Total Echo room volume V = 194.8 m3
Air temperature 22.9 C
Relative humidity 38.7 percent
Air pressure 101.6 kPa
Sketch position of the Tube Bass Trap units in the echo chamber with the positions of the sound source (1, 2, 3) and the microphone locations (m11, m12 ... m34).
Measuring and testing equipment:
Hand-held analyzer, type 2270 (Dual Channel), Bruel&Kjer
Sound pressure level calibrator type 4231, Bruel&Kjer
Condenser microphone Type 4189, Bruel&Kjer
Preamplifier Type ZC 0026, Bruel&Kjer
Power amplifier Type 2716, Bruel&Kjer
Sound source Type 4296, Bruel&Kjer
Termohigrometer Rotronic, Type Hygroclip S
Barometer Prazisions-Barometer

Symbols used in test results:
f – thirds center frequency in Hz
αS – coefficient of sound absorption at a center single frequency in thirds
T1 - Empty room Echo time (s)
T2 - Room response time with test samples (s)
αw – Laboratory proven coefficient of sound absorption
Tube trap D35 Laboratory results:
Tube Trap D35 response graph
Laboratory proven coefficient of sound absorption