Applications; Safety Notes; General Construction - Monacor DNU-400 Instructions D'assemblage

Please unfold page 5. Then you can always see the
indicated circuit diagram.

1 Applications

The DNU-400 is a printed circuit board for universal ap-
plications for the construction of passive speaker cross-
over networks in 3-way and 2
are possible connections for bi-wiring or bi-amping. With
this PCB approx. 4,000 different circuits may be realized
whereby different qualities or values of the components
have not yet been taken into consideration!

2 Safety Notes

The printed circuit board must exactly be assembled
according to these instructions. In case connections or
components are mixed up, amplifier and speakers
may be damaged or destroyed. In especially unfavour-
able cases there is a fire hazard by short circuits or
danger by exploding capacitors.
In case of faulty calculation of the components dam-
age to speakers and amplifier may also occur as well
as burnings by overloaded components.
Prior to switching-on check the precise assembly and
correct connection as a precaution. Only operate the
crossover network if all speakers have been connect-
ed.
If the component calculation is faulty or if the printed
circuit board is assembled in the wrong way, not cor-
rectly connected or used for purposes other than orig-
inally intended, no liability can be assumed for possi-
ble damage.
If the assembled printed circuit board is to be put out
of operation definitively, it must be disposed of in a lo-
cal recycling plant.

3 General Construction

The construction size, capability, and quality of the com-
ponents to be inserted can be selected as desired within
a technically reasonable range. No further drill holes or
mechanical auxiliary constructions are required to real-
ize the desired circuit. The circuit diagram on page 5
shows the possible maximum configurations when as-
sembling all existing component spaces. The framed
parts of the circuit mark the following circuit alternatives:
A midfrequency branch with a level attenuation or
B midfrequency branch with an impedance lineariza-
tion;
C high frequency branch with a level attenuation or
D high frequency branch with a slope of 18 dB
Bridge XY midfrequency branch as high pass/low pass or
Bridge XZ midfrequency branch as band pass
Different circuits can now be built up within the individual
branches by omitting components or by inserting jump-
ers, if necessary.
Note: The markings of the components are placing indi-
cations which are in general not according to the corre-
sponding markings of existing circuit diagrams. It is nec-
essary to arrange the components to be inserted
according to their functions.
1 / -way technique. There
2
4 Assembly
If the DNU-400 is not to be connected to a bi-wiring ter-
minal, connect the inputs "IN +B" and "IN +MH" as well
as "IN -B" and "IN -MH" with each other in each case.
By no means connect "+" and "-" with each other!
For a clear overview, the individual branches of the
network are separately dealt with in the following text:
TP low pass
MP midfrequency branch (often simplified: band pass)
HP high pass
Please always refer to the circuit diagram on page 5.
4.1 The low pass (TP)
The low pass divides the midrange and high frequencies
from the bass speaker. This function can be carried out
with different slopes. Furthermore, the inductive rise of
the bass speaker impedance can be linearized.
Always connect the bass speaker to the contacts "+B"
and "-B".
4.1.1 Low pass 6 dB without impedance linearization
Only assemble position L1.
4.1.2 Low pass 6 dB with impedance linearization
Assemble the positions L1, R1, and C2.
4.1.3 Low pass 12 dB without impedance
linearization
Assemble the positions L1 and C1. The capacity of the
parallel capacitor can also be composed of two capaci-
tors (positions C1 and C2). For this insert a jumper into
position R1. Then the parallel capacity is C1 + C2.
4.1.4 Low pass 12 dB with impedance linearization
Assemble the positions L1, C1, C2, and R1.
4.2 Midfrequency branch (MP)
This branch of the network, in general called band pass,
limits the transmission range of the midrange speaker to
the low and high frequencies. The respective frequency
range limiting can be made with a slope of 6 dB or 12 dB.
Concerning the slope indications (e. g. MP 6 dB/12 dB)
the first number always indicates the slope of the limiting
toward the low frequencies.
A linearization of the inductive rise of the speaker im-
pedance is possible or alternatively to this a level at-
tenuation of the midrange speaker. The special case of
1
the so-called 2 / -way combination is described in chap-
2
ter 4.4.
4.2.1 Midrange speaker protection
At first it should be determined if the midrange speaker is
to be equipped with a speaker protective device.
Important!
If no protective device is provided, solder a jumper into
position S1 in any case.
The following protective devices can be used here:
Soffits (e. g. PL-... and socket PLH-4 by MONACOR)
Circuit breakers (e. g. SFB-... by MONACOR)
Protection modules (e. g. DSP-1 by MONACOR) or
PTC resistors
Drill holes and construction space are directly provided
in field S1 for soffits with bracket and SFB components.
GB
9