D.A.S. Audio Aero - Manual (Page 39)

8. SIGNAL PROCESSING
Amplifier Data:
V = P * Z
V /S
V = P * Z
Limit level (v)=V /G
Limit level (dBu)=20log[limit level (v)/0.775]
Where P is the maximum power to be
delivered in watts
Example:
rms rms
rms
d d
d
d
G=
G =20log(V
/S)
Where P is the amplifier RMS power in
watts
Z is the load impedance in ohms
G is the amplifier gain
S is the amplifier sensitivity in volts
G is the amplifier gain in dB
Limiter settings:
dB rms
rms
dB
The use of the DSP-3VS digital processor is
highly recommended when running the AERO-38
sound system, and the use of the DSP-1Sub when
running the AERO-218Sub (AERO-182). Whenever
another loudspeaker management system is going to
be used, it should be configured with the parameters
provided by the manufacturer. Not doing so may
damage the system´s speaker components and
affect the sound quality.
The DSP-3VS digital processor is a three-
way crossover with gain controls that offer +/- 6dB
variation per way. The processor has two inputs and
six outputs with level indication and muting for each
of the outputs. The digital processor includes fourth
order filters and parametric equalizers. The user
adjustable limiters are accessible from the front panel.
The DSP-3VS includes 10 presets that can
be selected from the front panel. Each preset memory
recalls specific operating parameters for a specific
DAS speaker systems. The selected program is visible
on the LCD screen located on the front panel.
Amplifier
32dB
750W@4ohm
40 X
1.58 volts@8ohm
G dB
P rms
G
S
500W@8ohm
1.34 volts@4ohm
two
P =400W@8ohm
V = 400*8=56.57v
Limit level (v)=V /G=56.57/40=1.41
Limit level (dBu)=20log(1.44/0.775)=5.2
d
d
d
Limit level (dBu)=20log(Vd/0.775)-G dB
In this example we are going to feed the
highs of AERO-38 with one amplifier channel.
Total impedance of 2 ND-10 high frequency drivers, as
wired in the AERO-38, is 8 Ohms. The maximum rms
power to be delivered to the highs, or Pd, should be
400W (400/2=200W per driver).
Important Notice: The programs stored in
the memories of the DSP-3VS have been designed to
provide optimum performance and balance between
the different ways. In order to maintain this balance,
equal gain amplifiers should be used.
Another formula to calculate the limiters:
8.2 LIMITER SETTINGS
8.1 DSP-3VS INSTRUCTIONS
To select a program, turn the rotary mini-DIP
switch on the front panel labelled “Presets”. The name
of the recalled preset will appear on the LCD screen.
The first time the DSP-3VS is connected, the number 1
program for the AERO-48 system will appear on the
front panel screen.
To select the limit levels for each of the
ways, turn the rotary mini-DIP switches on the front
panel labelled “Limiters”. The limit level expressed in
Vrms and dBu appears on the front panel screen.
The “Settings” button allows the user to
check the saved limit levels. The limit levels appear on
the screen and after 5 seconds, the preset program
returns to the screen.
The limit levels to be entered should be equal
to or lower than the sensitivity of the amplifiers used.
Amplifier manuals provide the sensitivity at 8 Ohms
and 4 Ohms. Take into account the load impedance at
which the amplifiers will be working when adjusting
the limit levels.
When using amplifiers with a greater output
power than that recommended by the speaker
manufacturer, the limit levels should be adjusted so
not to exceed the power capabilities of the speakers.
The following formulas can be used to establish the
limiter voltage:
79
Aero-38
Manual del usuario/ User´s manual