Alpine IVA W505 Owners Manual - Page 245

Calling up the Preset Memory 1 Check whether the Defeat mode is off. 2 Touch any one of the preset buttons [P.SET 1] through [P.SET 6] on the A.PROCESSOR list display to select the preset memory. • It takes a few moments to call up the preset memory. Setting the Subwoofer 1 Touch [SETUP] on the main source screen. The SETUP selection screen is displayed. 2 Touch [AUDIO SETUP]. The AUDIO SETUP screen appears. 3 Touch [ ] or [ ] of SUBWOOFER to set the subwoofer ON/OFF. 4 Touch [ ] of SUBWOOFER after setting the SUBWOOFER to ON. The SUBWOOFER SETUP screen appears. Setting items: LEVEL / PHASE / SYSTEM / CHANNEL Adjusting the Subwoofer Level Touch [ ] or [ ] of LEVEL to adjust the SUBWOOFER output. Setting range: 0 to 15 Setting the Subwoofer System When the subwoofer is on, you can select either System1 or System2 for the desired subwoofer effect. Touch [ ] or [ ] of SYSTEM to select SYSTEM 1 or SYSTEM 2 SYSTEM 1 : Subwoofer level changes according to the main volume setting. SYSTEM 2 : Subwoofer level change is different from the main volume setting. For example, even at low volume settings, the subwoofer is still audible. Setting the Subwoofer Phase Touch [ ] or [ ] of PHASE to select 0° or 180° The subwoofer output phase is toggled SUBWOOFER NORMAL (0°) or SUBWOOFER REVERSE (180°). Setting the Subwoofer Channel You can set the subwoofer output to stereo or monaural. Make sure to set the correct output for your subwoofer type. Touch [ ] or [ ] of CHANNEL to select STEREO or MONO. STEREO: Subwoofer stereo (L/R) output MONO: Subwoofer monaural output About Time Correction The distance between the listener and the speakers in a car vary widely due to the complex speaker placement. This difference in the distances from the speakers to the listener creates a shift in the sounds image and frequency characteristics. This is caused by the time delay between the sound reaching the listener's right versus the left ear. To correct this, this unit is able to delay the audio signal to the speakers closest to the listener. This effectively creates a perception of increased distance for those speakers. The listener can be placed at an equal distance between the left and right speakers for optimum staging. The adjustment will be made for each speaker in 3.4cm steps. Example 1. Listening Position: Front Left Seat Adjust the time correction level of the front left speaker to a high value and the rear right to zero or a low value. 0.5m 2.25m 5.1ms The sound is not balanced because the distance between the listening position and the various speakers is different. The difference in distance between the front left speaker and the rear right speaker is 1.75 m (68-7/8"). Here we calculate the time correction value for the front left speaker in the diagram on the above. Conditions: Farthest Speaker - listening position : 2.25 m (88-9/16") Front left speaker - listening position : 0.5 m (19-11/16") Calculation: L = 2.25 m - 0.5 m = 1.75 m (68-7/8") Time correction = 1.75 ÷ 343*1 × 1000 = 5.1 (ms) *1 Speed of sound: 343 m/s (765 mph) at 20°C In other words, giving the front left speaker a time correction value of 5.1 ms makes it seem as if its distance from the listener is the same as the distance to the farthest speaker. Time correction eliminates the differences in the time required for the sound to reach the listening position. The time of the front left speaker is corrected by 5.1 ms so that its sound reaches the listening position at the same time as the sound of other speakers. Example 2. Listening Position: All Seats Adjust the time correction level of each speaker to almost the same level. 1 Sit in the listening position (driver's seat, etc.) and measure the distance (in meters) between your head and the various speakers. 2 Calculate the difference between the distance correction value to the farthest speaker and the other speakers. L = (distance to farthest speaker) - (distance to other speakers) 54-EN