Top 2 alternative sites to catt.se
Rhintek Incorporated
Rhintek, Incorporated: The Distributor for CARA, A Software Simulation of Room Acoustics and Sound Modeling.
Author: David Seymore
REW - Room EQ Wizard Room Acoustics Software
REW is free software for room acoustic measurement, loudspeaker measurement and audio device measurement and analysis
Author: John Mulcahy