RCF UP 9501, Руководство пользователя

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33
ENGLISH
Within the system operation limits, the result is equal to 1 in almost all cases.
The only exception is given by a line with two branches including horn speakers only and
connected to a 500 W amplifier. In this case, it is advisable to add two EOL (in parallel) to
the end of each line branch (to fall within the correct measurement range).
Anyway, to know how many EOL are needed in a line, it is necessary to calculate the total
impedance
(Ztot) by applying the following formula (parallel impedances), adjusted with
the EOL number (Neol) :
NotE:
The line impedance
( Zline )
here is considered aT The frequency of
20 h
z
(
which is noT
equal To The one measured by an impedance meTer aT
1
k
h
z
)!
The total impedance must respect the constraints about EOL.
EOL number shall not exceed the maximum amount (as indicated previously).
NotE:
The line impedance
( Zline )
here is considered aT The frequency of
20 h
z
(
which is noT
equal To The one measured by an impedance meTer aT
1
k
h
z
)!
In case of a single line having a particularly low impedance load or lines including
horn speakers (open circuits at 20 Hz), it will be necessary to add more EOL in
parallel.
In case the line is divided into more branches, in each branch the EOL number
needs to be the same, in order to guarantee a proper monitoring and respect
the following formula:
Ztot =
Zline Zeol
Zline – Zeol
Neol > =
200 Ω
Ztot (21 – Nbranch)
Ztot = total impedance
Nbranch = line branch number
Neol = EOL number
Ztot =
Zline
Zline +
200 Ω
Neol
200 Ω
Neol
The total impedance (
Ztot
) resulting from the parallel between the load impedance
already present in the line ( Zline ) and EOL ( Zeol = 200 Ω) is easily obtainable by the
following formula: