1
DSP Features in brief
In the BLOCK DIAGRAMS below you can see the CORE DSP processing paths.
NOTE:
the DSP INPUT section is always fully editable by the user, but the OUTPUT section can have restrictions for
FACTORY or PROTECTED presets. In those presets some parameters can’t be edited or viewed.
For STEREO and PARALLEL configurations ganging option is available for input and output, to pair easily the sections of
the CORE DSP processed channels.
Speaker protection setting
Replacing a professional speaker is an expensive cost and reducing this risk is good, so many users want to know how
to set a limiter properly for the speaker protection.
The QC amplifiers like the loudspeaker processor can protect the speaker from excessive heating using the OUTPUT
LIMITER, though it is not possible to
protect a speaker from every possible
cause that occurs to damage it, over-
excursion, very unnatural sound signals
or an erroneous cross-over filter setting
and so on could damage a speaker.
To protect a speaker from over heating
you have to know some its technical
data:
1) The speaker power handling
(PAES) measured with the AES2-1984
(r2003) standard (AES Recommended
Practice - Specification of loudspeaker
components used in professional audio
and sound reinforcement), usually it
is indicated in the speaker technical
data in W
AES
, this standard is actually
the best method to know the power
handling capability of the speaker for
a standard music program. In case of
a group of speaker connected to the
same channel you have to consider the
whole power handling.
2) The nominal impedance (Z
NOM
)
of the speaker and/or the resulting
nominal impedance of the group
of speaker connected at the same
amplifier channel (typically 4 or
8 ohm). So to calculate the limiting
threshold a simplified expression must
be executed:
delay
limiter
gain
phase
mute
out
Dynamic Eq.
fi
lters
parametric/shelving
5 band parametric
or shelving
fi
lters
xover
LP
HP
VU meter
level
1
2
3
4
5
1
2
3
user parameters for each OUTPUT CORE DSP sec
ti
on
compressor/limiter
delay
5 band parametric
or shelving
fi
lters
1
2
3
4
5
mute
phase
level
VU
meter
user parameters for each INPUT CORE DSP sec
ti
on
݈݂ܵ݅݉݅݅݁݀ ݁ݍݑܽݐ݅݊ ݐ ݈ܿܽܿݑ݈ܽݐ݁ ݐ݄݁ ݑݐݑݐ ݈݅݉݅ݐ݁ݎ ݐ݄ݎ݁ݏ݄݈݀:
ܱܷ݈ܶ݅݉݅ݐ݁ݎ
(ௗ)
= 20 כ ܮ݃
ଵ
ඥܲ
ாௌ
כ ܼ
ேைெ
ඥܲ
ெ
כ ܼ
ை
ݓ݄݁ݎ݁:
ܱܷ݈ܶ݅݉݅ݐ݁ݎ
(ௗ)
= ݑݐݑݐ ݈݅݉݅ݐ ݐ݄ݎ݁ݏ݄݈݀ ݅݊ ݀ܤ ݎ݈݁ܽݐ݁ ݐ
ݐ݄݁ ݉ܽݔ݅݉ݑ݉ ݓ݁ݎ , ݈ܽݓܽݕݏ ݊݁݃ܽݐ݅ݒ݁.
ܲ
ாௌ
= ܵ݁ܽ݇݁ݎ ݓ݁ݎ ݄݈ܽ݊݀݅݊݃ ݅݊ ܹ
ாௌ
ܼ
ேைெ
= ܵ݁ܽ݇݁ݎ ݈݊݉݅݊ܽ ݅݉݁݀ܽ݊ܿ݁, ݑݏݑ݈݈ܽݕ 4 ݎ 8 ߗ.
ܲ
ெ
= ܯܽݔ݅݉ݑ݉ ܿ݊ݐ݅݊ݑݑݏ ݑݐݑݐ ݓ݁ݎ
݂ ݐ݄݁ ݈݂ܽ݉݅݅݁ݎ ݅݊ ܹ.
ܼ
ை
= ܫ݉݁݀ܽ݊ܿ݁ ݂ ݐ݄݁ ݈ܽ݀ ݂ݎ ݐ݄݁ ݏ݂݁ܿ݅݅݁݀ ܲ
ெ
݁ݔ݈ܽ݉݁: ݑݏ݅݊݃ ܽ ܳܥ4.2 ܾ݈ܿܽܽ݁ ݂ ݈݀݁݅ݒ݁ݎ 500ܹ ܽݐ 4ߗ
ݓ݁ ݓܽ݊ݐ ݐ ݎ݁݀ݑܿ݁ ݐ݄݁ ݓ݁ݎ ݂ݎ ܽ ݏ݁ܽ݇݁ݎ ܾ݈ܿܽܽ݁ ݂
݄݈ܽ݊݀݅݊݃ 100ܹ ܽݐ 8ߗ ݏ:
ܱܷ݈ܶ݅݉݅ݐ݁ݎ
(ௗ)
= 20 כ ܮ݃
ଵ
ξ100 כ 8
ξ500 כ 4
= െ4݀ܤ
