Alpine iDA-305 owner manual About the Crossover, 35-EN, Crossover X-OVER, SUBW. Mode, 3WAY Mode

About the Crossover

Crossover (X-OVER):

This unit is equipped with an active crossover. The crossover limits the frequencies delivered to the outputs. Each channel is controlled independently. Thus, each speaker pair can be driven by the frequencies for which they have been optimally designed.

The crossover adjusts the HPF (high pass filter) or LPF (low pass filter) of each band, and also the slope (how fast the filter rolls off the highs or lows).

Adjustments should be made according to the reproduction characteristics of the speakers. Depending on the speakers, a passive network may not be necessary. If you are unsure about this point, please consult your authorized Alpine dealer.

F/R/SUBW. Mode

	Cut-off frequency		Slope
	(1/3 octave steps)				Level
	HPF	LPF	HPF	LPF
Low range		20 Hz -		FLAT, 6,	0 to
	----		----	12, 18,
speaker		200 Hz			-12 dB
				24 dB/oct.
Rear high	20 Hz -	----	FLAT, 6,	----	0 to
range			12, 18,
	200 Hz				-12 dB
speaker			24 dB/oct.
Front high	20 Hz -		FLAT, 6,		0 to
range		----	12, 18,	----
	200 Hz				-12 dB
speaker			24 dB/oct.

Low range High range

(Different from actual display)

3WAY Mode

	Cut-off frequency		Slope
	(1/3 octave steps)				Level
	HPF	LPF	HPF	LPF
Low	----	20 Hz -	----	FLAT, 6,	0 to
range				12, 18,
		200 Hz			-12 dB
speaker				24 dB/oct.
Mid range	20 Hz -	20 Hz -	FLAT, 6,	FLAT, 6,	0 to
			12, 18,	12, 18,
speaker	200 Hz	20 kHz			-12 dB
			24 dB/oct.	24 dB/oct.
High	1 kHz -		FLAT*
	20 kHz,				0 to
range		----	6, 12, 18,	----
	(20 Hz ~				-12 dB
speaker			24 dB/oct.
	20 kHz)*

*Only when selecting User’s in “Setting the Response Slope for the High Range Speaker (Tweeter)” (page 30).

Low range Mid range High range

(Different from actual display)

Level adjusting
(0 to -12 dB)	Output frequency range
			Slope FLAT
			Slope adjusting
20 Hz			(Different from actual display)
	HPF cut-off	LPF cut-off
	frequency	frequency

•HPF (high pass filter): Cuts the lower frequencies and allows the higher frequencies to pass.

•LPF (low pass filter): Cuts the higher frequencies and allows the lower frequencies to pass.

•Slope: The level change (in dB) for a frequency change of one octave.

•The higher the slope value, the steeper the slope becomes.

•Adjust the slope to FLAT (0 dB/oct) to bypass the HP or LP filters.

•Do not use a tweeter without the HPF on or set to a low frequency, as it may cause damage to the speaker due to the low frequency content.

•You cannot adjust the crossover frequency higher than the HPF or lower than the LPF.

•Adjustment should be made according to the recommended crossover frequency of the connected speakers. Determine the recommended crossover frequency of the speakers. Adjusting to a frequency range outside that recommended may cause damage to the speakers.

For the recommended crossover frequencies of Alpine speakers, refer to the respective Owner’s Manual.

We are not responsible for damage or malfunction of speakers caused by using the crossover outside the recommended value.

35-EN