Alpine PXI-H990 owner manual 27-EN, Concrete examples

4 Divide the distances calculated for the different speakers by the speed of sound (343 m/s temperature 20°C).

This value is the time correction value for the different speakers.

•The speed of sound fluctuates according to the temperature. The accurate speed of sound

can be achieved with the formula shown below. Speed of sound = 331.45 + C ⋅ T

C: 0.607

T:Temperature (°C)

•Concrete examples

1.Calculating the time correction value for the front left speaker on the diagram below.

Conditions:

Distance between farthest speaker and listening position: 2.25 m (88-3/4")

Distance between front left speaker and listening position: 0.5 m (20")

Calculation: L = 2.25 m (88-3/4") – 0.5 m (20") = 1.75 m (68-3/4") Compensation time = 1.75 ⎟ 343 ⋅ 1000 = 5.1 (ms)

In other words, setting the time correction value for the front left speaker to 5.1 (ms) sets a virtual distance matching the distance to the farthest speaker.

5.1ms 0.5m

2.25m

The sound is uneven because the distance between the listening position and the different speakers is different.

The difference in the distance between the front left and rear right speakers is 1.75 meters (68-3/4").

Time correction eliminates the difference between the time required for the sound from the different speakers to reach the listening position.

Setting the time correction of the front left speaker to 5.1 ms makes it possible to coordinate the distance from the listening position to the speaker.

Continued

27-EN