MACKIE S408 - Manual (Page 6)

6
CONNECTIONS
The S408 has two connectors labeled INPUT and
THRU. These are both Neutrik Speakon™ connectors,
which provide a secure and reliable connection for the
loudspeakers. These connectors are wired in parallel,
and allow for connecting the input signal to another
speaker’s input.
NEVER connect more than one
output from a power amplifier to the
S408 INPUT or THRU connector.
Keep in mind, when connecting two or more speakers
in parallel using the THRU connections, that you want
to avoid going below the minimum impedance require-
ments for your power amplifier.
The S408 has a nominal impedance of
8 ohms.
Two S408s in parallel equals 4 ohms.
Three S408s in parallel equals .7 ohms.
Four S408s in parallel equals  ohms.
Use high-quality speaker cable as recommended by
the power amplifier manufacturer.
DO NOT use coaxial shielded cable
like a guitar cord to make speaker
connections. They are not designed
to handle the high currents required
to drive a loudspeaker.
The Speakon connector is wired as follows:
Pin 1+ = Signal (“+” or hot)
Pin 1– = Ground (“–” or cold)
PlACEMENT
A number of placement options are available with the
S408. It can sit on the floor or stage, or it can sit on top
of the S410s subwoofer. It can also be placed on the floor
horizontally as a monitor wedge. It can be mounted on
a speaker stand via the built-in socket on the bottom
of the cabinet or pole-mounted on top of the S410s
subwoofer. Be sure the speaker stand or pole is
capable of supporting the weight of the S408.
You can create a horizontal array by placing the cabi-
nets side-by-side. However, you should have a good un-
derstanding of the relationship between the splay angle
(the angle between the facing sides of the cabinets),
the on-axis power, and frequency cancellation effects
between cabinets.
When two cabinets are placed side-by-side, the actual
splay angle is 75º (determined by a 7.5º angle on each
cabinet side). Since the horizontal coverage of the S408
is 75º, this provides a smooth transition throughout the
coverage area, minimizing comb-filtering effects.
COLD
HOT
1+
1+
1–
1–
2–
2+
Speakon Connectors
37.5
º 37.5
º
75º
WARNING: We do not recommend
stacking two S408 loudspeakers on
top of each other. They are front-
heavy and run the risk of tipping
over. If you do stack two S408 cabi-
nets or an S408 on top of an S410s, we recommend that
the cabinets be tethered to the ground in back of the
cabinets to secure them in a stacked position so they
cannot fall forward.
Room Acoustics
The S408 loudspeakers are designed to sound as neu-
tral as possible; that is, to reproduce the input signal as
accurately as possible.
Room acoustics play a crucial role in the overall per-
formance of a sound system. Here are some additional
placement tips to help overcome some typical room
problems that might arise: