Soundstream Technologies HRU. 4, HRU. 2 owner manual Hawkins Bass Control Theory and Use

Hawkins Bass Control - Theory and Use

Hawkins Bass Control ( parametric) is a unique subwoofer control circuit included with the Soundstream Human Reign Unleashed amplifiers. It is capable of removing subsonic energy in program material while boosting subwoofer frequencies.

The circuit consists of two controls. One adjusts the frequency of operation and the other adjusts the range of boost.

With both controls adjusted fully counter-clockwise, no boost is applied and the amplifier is flat in response down to 20 Hz.

The frequency control adjusts the
starting point of the subsonic filter. The
high pass filter has two frequency ranges.
When the bass control switch is set to
“SUBSONIC”, the high pass filter frequency
can be adjusted from 13 Hz up to a maximum
of 30 Hz. In this setting, no boost “Q” control	FIG. 2 VARIABLE “Q”
is available. This control is useful for setting
the lowest frequency that your subwoofer
will see (see figure 1).
When the bass control switch is set to
“HAWKINS BASS CONTROL” the high pass
filter frequency can be adjusted from 30 Hz
to a maximum of 70 Hz. In this setting, there
is an available boost control of 0 to +9dB.
	FIG. 3 VARIABLE HIGH PASS

The Boost control adjusts the amount of level applied at the set frequency.

This is adjustable from flat (0dB) to +9dB. (See figure 2)

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

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