5. Multiple cabinet
configurations
When more than one cabinet per
side is used in a PA system, it is
important to pay attention to
over the total load impedance
that your configuration exhibits
to the power amplifier. The
available output power from an
amplifier varies with the speaker
impedance and every power
amplifier has a lowest allowed
load value that has to be observed.
5.1 Parallel wiring
In a speaker setup, 'parallel
wiring' means that all
correspondent terminals are
wired together: all 'hot' (plus)
terminals are wired together, the
same goes for all 'ground' (minus)
terminals. Wiring speakers in
parallel always lowers the total
impedance. If N speakers with the
same impedance R are wired in
parallel, the total impedance R
tot
is always R
tot
= R/N. If the speakers
have different impedance R
1
, R
2
,
R
3
, and so on, you have to use the
following formula:
If you have only two speakers
with different impedance R1 and
R2, the formula simplifies to:
As said before, never connect a
total speaker impedance R
tot
to an
amplifier that is lower than its
lowest allowed load. Disregarding
this rule leads to overheating of
the power amplifier, resulting in
its destruction or triggering of the
thermal shutoff circuitry.
5.2 Example for parallel
wiring
Three cabinets are wired in
parallel:
•
Cabinet 1 with R
1
=8 ohms
•
Cabinet 2 with R
2
=8 ohms
•
Cabinet 3 with R
3
=4 ohms
Using formula a) yields:
1/R
tot
= 1/8 + 1/8 + 1/4 = 1/2
resulting in: R
tot
= 2 ohms
This means that the power
amplifier 'sees' a single total load
of 2 ohms.
6. Connectors
All Club series cabinets are
equipped with Speakon
connectors exclusively. When
connecting a Speakon plug,
always twist the entire plug
clockwise for a 1/3 turn after
insertion until it 'snaps' into
contact position.
7. Service
If you should experience any
problems with your Club series
cabinet, contact your local Zeck
distributor.
12
Owner’s Manual Club series © Zeck Audio
R
tot
=
R
1
x R
2
R
1
+ R
2
R
1
1
1
1
1
R
2
R
3
R
tot
a)
b)
+
+
=
...
1
1
1
1
4
Ω
R
tot
1
2
Ω
+
+
=
=
R
tot
= 2
Ω
8
Ω
8
Ω
Parallel wiring of Club series cabinets.
R
