The picture above shows the comparison of a CARA calculation of the sound pressure frequency response (red) with the corresponding measurement results (green).

The listening room has the dimensions (L/W/H) 8.06/5.87/2.62 m. At the corners in the front special foamed rubber absorbers are located. In the rear a bookshelf is mounted with a door deepened by 60 cm. At the left side wall another bookshelf of approx. 8 sqm size is placed.

The 2 ways test loudspeaker is placed on a stand at the height of 90 cm, the distance to the microphone amounts to 3 m. Both have a distance of 1.6 m to the front wall. The distance of the test box to the left side wall is 1.8 m.

The frequency response has been calculated with a 'Maximum Reflection Order' of 12.

The comparison shows a very good matching of the measurement results with the CARA calculation. We do not know any other comparable room acoustics simulation program that is able to present this high quality matching. The reason for this may be, that other programs mostly do not take into account the phase part of the complex sound pressure amplitude. Furthermore, the loudspeaker models used for the calculations may not be sufficiently precise.

For example CARA uses 4,000 complex frequency responses (1,000 directions around the speaker at 4 different distances) from 5 to 40,960 Hz (spacing 1/9 octaves) to model the sound radiation of a speaker.