Alpine HDS-990 HDS-990 Owners Manual - Page 25

After the factory settings are restored, all the setting items will be restored to the factory default settings except for the debugged "Dealer Settings" mode. Setting items: In the setting interface, long press next song, long press the knob, and long press previous song to call out the DIAG mode. Setting content: Firmware update: Enter the firmware update interface, select the firmware update file, and then short press to confirm to update the version. Dealer setting: Short press to save dealer settings. Serial number: You can view the serial number of the machine. About the X-Over Frequency divider (X-Over): This machine is equipped with an active frequency divider. The frequency divider can limit the frequency that reaches each output. Each channel can be controlled individually. Therefore, each pair of speakers can be driven with an optimized frequency. The frequency divider can adjust the HPF (high pass filter) or LPF (low pass filter) of each band, and the slope (the speed of the filter to the high point or low point). Should be adjusted according to the reproduction characteristics of the speaker. Depending on the speakers, it may not be necessary to use a passive network. If you are not sure about this, please consult an authorized Alpine dealer. Active 2-way: Cut-off frequency (The level difference is 1/3 octave band) Slope HPF LPF HPF LPF Subwoofer speaker ---- 20Hz-8 00Hz ---- 6/12/18/24 /30/36/42/ 48dB/oct. Rear (high frequency) speakers Front (high frequency) speakers 20Hz-80 0Hz 1kHz-20 kHz 20Hz-2 0kHz ---- 6/12/18/24/ 30/36/42/4 8dB/oct. 6/12/18/24/ 30/36/42/4 8dB/oct. 6/12/18/24 /30/36/42/ 48dB/oct. ---- Active 3-way: Cut-off frequency (The level difference is 1/3 octave band) Slope HPF LPF HPF LPF Woofer speaker Mid-range high-pass speaker Mid-range low-pass speaker Tweeter speaker ---- 20Hz-80 0Hz 20Hz-80 0Hz 1kHz-20 kHz 20Hz-8 00Hz 20Hz-2 0kHz 20Hz-2 0kHz ---- ---- 6/12/18/24 /30/36/42/ 48dB/oct. 6/12/18/24 /30/36/42/ 48dB/oct. 6/12/18/24 /30/36/42/ 48dB/oct. 6/12/18/24/ 30/36/42/4 8dB/oct 6/12/18/24/ 30/36/42/4 8dB/oct. 6/12/18/24/ 30/36/42/4 8dB/oct. ---- 22 EN