HELIX Blue B 8DSP Instruction Manual page 18

Sound characteristics modes
level
Diagram with frequency range of the two
sound characteristic modes
The „SQ" setting provides an optimum linear fre-
quency response with low cut-off frequency at
slightly reduced maximum sound pressure level.
It means that the frequencies below the cut-off
frequency are reproduced at the same sound
Slope modes (1)
level
Diagram of the two slope modes
The designated cutoff frequency can be adjusted
with the lowpass frequency control (5). In the
upper diagram the cutoff frequency is at 100 Hz.
Signals above this frequency are reproduced
progressively weaker.
level. Thus the maximum volume of the subwoo-
fer is slightly reduced.
The „SPL" setting enables a higher sound pres-
sure in the range of 60 to 70 Hz at slightly lower
deep bass reproduction. In this mode the volume
of the deep frequencies (20 Hz to 40 Hz) is redu-
ced, therefore the maximum sound level is signi-
ficantly increased.
At setting „12" the frequencies above the cut-off
frequency turn slowly down. With every frequen-
cy doubling (one octave) the volume is reduced
by 12 dB. In this diagram you can see, that the
volume at 200 Hz is 12 dB lower than at 100 Hz.
With setting „24" the frequencies above the ad-
justed frequency will be abruptly and significantly
lowered, in this case 24 dB per octave.
Autogoods "130"
···
SPL-mode
SQ-mode
frequency
···
24 dB-mode
12 dB-mode
frequency
17