Mesa/Boogie 55 Stereo Amplifier User Manual


 
PAGE 35
PARALLEL:
When wiring in parallel, the resistance of the speakers decreases. Two 8 ohm speakers wired in ( hooked-up ) Parallel
results in a 4 ohm load. It’s easy to calculate the effect of a resistive load when all the speakers are all the same resistance. It is really not
suggested to wire different resistive load values in Parallel ( 8 and 4, 16 and 8 etc. ) The formula for figuring the total impedance in Parallel
is the multiplication of the two loads divided by the sum of the two loads - i.e. putting two 8 ohm speakers in Parallel results in a 4 ohm load.
Connect the Positive side of Speaker A to the Positive side of Speaker B - Connect the Negative side of Speaker A to the Negative side of
Speaker B.
COMBINATION OF SERIES & PARALLEL:
This is really just two sets of Parallel wired speakers connected in series. This is how
you maintain a consistent load with multiple speakers. The importance of this is more evident when you have more than one cabinet to
connect to your amplifier. This is when
you need to figure out the loads and how
to wire them up without applying too low
of a resistance on the amplifier.
Simply connect the Positive side of
Speaker A to the Positive side of Speaker
C.
Connect the Negative side of Speaker A
to the Positive side of Speaker B, then
on to the Positive side of Speaker D and
finally on to the Negative side of Speaker
C.
And lastly, connect the Negative side of
Speaker B to the Negative side of
Speaker D.
4 Eight ( 8 ) Ohm speakers wired in Se-
ries Parallel = a Total Load of 8 Ohms.
SPEAKER IMPEDANCE MATCHING & HOOK-UP GUIDE: (Continued)
POSITIVE
Speaker A
8 Ohms
Speaker B
8 Ohms
NEGATIVE
Total Load = 4 Ohms
Made by
Electro-Voice
B
L
A
C
K
S
H
A
D
O
W
Made by
Electro-Voice
B
L
A
C
K
S
H
A
D
O
W
Made by
Electro-Voice
B
L
A
C
K
S
H
A
D
O
W
Made by
Electro-Voice
B
L
A
C
K
S
H
A
D
O
W
SPEAKER A
SPEAKER B
SPEAKER C
SPEAKER D
POSITIVE
NEGATIVE
All 4 Spkrs.
are 8 Ohms