AFMG Network Forum

esonic · Member

I use EASE a long time for enclosed en open spaces, for open spaces i close the model with with a 100% tot 80% absorbing lid.

For a recent project i have a large concrete box without cover, dimension 8x 150 meter.

I did only STIPA measurements on site, with recording. I i compare the results with the actual measurements, i have no good match. The STI is too optimistic.

I am looking to find ways and settings to tune the model, but the surface are almost complete reflective.
Are there ways, or is this geometry too extreme ?

thanks jurjen.

Bruce · Member

Hello Jurjen,

I have not quite followed what you are doing.

How large is the box?
1200 meters on each side?
Is the cover 80% or 100% absorbing?

What source was used for the STIPA measurements?
What was the measured ambient noise?
What did you use to simulate the STI?
EASE Mapping?
AURA Mapping?
AURA Response?
Did you use the Masking and Noise options?

esonic · Member

Hi Bruce,

The box is 8 meters wide, 8 meters deep and 150 meters long.
The water level is 8 meters below the top or 0.5 meters. (shipping lock)

The lid is open, i put 60% 80 or 90% in the lid area.

STIPA mesurements were done with a test loudspeakers (twin cluster speech horn)
Test system is Xl2-TA with mr-pro generator.

1m level is taken from test loudspeaker, on axis.

Also STIPA signal is recorded on the XL2 with mute for decay analysis.
Decay and signal/noise is analyzed with DIRAC.

The raw modulation factors are compared from the STIPA data and from the AURA ray-tracing. (mtf table from probe)
For STIPA the noise and signal masking are active, also in EASE, the 4th edition STI is used.
Direct and reverberant sound levels do match.

The project information and a more detailed report including pictures has been sent.

regards jurjen