Soundstream Technologies 1002, 702, 502 owner manual Adjustment

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HAWKINS

BASS

CONTROL

r HAWKINS 1

FREQ FREQ BOOST

110

Hawkins Bass Control (parametric) is a unique subwoofer control circuit included with the Soundstream RUBICONSM, 702 and 1002 am- plifiers. It is capable of removing subsonic en- ergy in program material while boosting subwoofer frequencies. The circuit consists of two controls. One adjusts the frequency of op- eration and the other adjusts the range of boost. With both controls adjusted fully counter-clock- wise, no boost is applied and the amplifier is flat in response down to 20 Hz.

Application	8 0
Subwoofer drivers in general have	7 0
excellent power handling character-	6 0
	5.0
istics over their operational band-
	(,?I$0
width. This bandwidth is determined
	30
by many factors, including driver de-	20
	I O
sign, and enclosure type. It is pos-
	0.0 10 Frequency(Hz)	50	100	200

sible to overdrive any subwoofer	FIG. 5 LIMITED EXCURSION
driver by sending powerful signals

outside of its operational bandwidth. These potentially damaging signals can be removed by adding a subsonic filter. Figure 5 shows the effective-

FIG. 1 BASS CONTROL

ness of the Hawkins Bass Control on woofer excursion in a vented enclo-

The frequency control (Hz) adjusts the starting point of the subsonic fil- ter. On the RUBICON502,702 and dB 1002, the high pass filter has two fre- quency ranges. When the bass con- trol switch is set to “SUBSONIC”, the high pass filter frequency can be adjusted from 13 Hz up to a maxi- mum of 30 Hz. In this setting, no boost “Q” control is available. This control is useful for setting the low- est frequency that your subwoofer dB will see (see figure 1). When the bass control switch is set to

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0

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-30lOFrequency 50 100 200

FIG. 2 VARIABLE “Q”

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0

-5

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sure. The woofer travels 7.5 mm at 10 Hz. With Hawkins Bass Control properly adjusted, this excursion can be reduced to less than 1 mm. This is of great benefit to lowering woofer distortion and increasing output.

Adjustment

An easy method of optimizing your existing subwoofer enclosure with Hawkin’s “Hz” control is as follows.

1.Adjust frequency and boost control to full CCW position.

2.Set the bass control switch to “HAWKINS BASS CONTROL”.

3.While listening to music with strong bass content at a moderate level, slowly adjust frequency control clockwise. Listen for a reduction of bass response. Now, rotate frequency control slightly backwards. This serves the purpose of removing the “subsonic” bass energy.

“HAWKINS BASS CONTROL”, the high pass filter frequency can be ad- justed from 30 Hz to a maximum of

70 Hz. In this setting, there is an available boost control of 0 to +9 dB.

-25

-3010 Frequency(Hz)

FIG. 3 VARIABLE HIGH PASS

With Soundstream’s Hawkins Bass Control, the boost and frequency con- trol can provide virtually any combina- tion of boost and cut to suit your de- signs. So, Hawkins Bass Control can

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5

0

-5

dB

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5

0

-5

dB

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-15

-20

-25
	I	I	I IIIIIII		1
-3010		Frequency (Hz)	50	100	200

FIG. 4 VARIABLE BOOST

The Boost control adjusts the amount of level applied at the set frequency. This is adjustable from flat (OdB) to +9 dB. (See figure 2)

When the Boost is set to 0, Hawkins acts as a sub-sonic filter only. (See figure 3) The simple act of removing potentially harmful low frequencies can improve system output by as much as 3 dB. (see figure 4)

provide the “tailoring” needed for any type of “assisted” design and any woofer in any type of installation.

-15

-20

-25

-3010 Frequency(Hz) 50 100 200

FIG. 6 VARIOUS SETTINGS

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