Certified Acoustic 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
Setting the testing equipment and Tube Bass Traps with reflection side toward the microphone into the Echo Chamber
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
Note at the pictures that metal plate on the Tube Trap disc points to the mid surface of passive absorber/reflection side inside Trap
Tube Bass Trap in Diameter 35 cm Acoustic chamber Sketch with position details about the: - sound source (1, 2, 3) - microphone locations (m11, m12 ... m34).
Tube Bass Trap in Diameter 35 cm Laboratory results
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 Bass Trap in Diameter 35 cm response graph
