JBL MS-10SD2 Owner's Manual page 3

2. You must use both coils of a dual voice-coil woofer connected
either in series or in parallel.
3. Most amplifiers deliver exactly the same amount of power bridged
into a 4-ohm load as they do running a 2-ohm stereo load.
To design a subwoofer system that maximizes available amplifier power,
keep the following rules in mind:
1. The total system impedance of woofers in parallel can be calculated
using this formula:
1
Impedance =
1 + 1 + 1
w w w
1 2 3
where w is the nominal impedance of the woofer.
2. The total system impedance of voice coils (or woofers) in series can
be calculated using this formula:
Impedance = w + w + w ...
1 2 3
The diagrams below show parallel and series speaker connections.
Figure 1. Parallel connection
...
Figure 2. Series connection
SUGGESTED ENCLOSURES
MoDELS SEaLED BoX
Internal Volume Internal Volume Qty.
MS-10SD2 0.78 ft (22L) 1.13 ft
3
MS-10SD4 0.78 ft (22L) 1.13 ft
3
MS-12SD2 0.95 ft (27L) 1.7 ft
3
MS-12SD4 0.95 ft (27L) 1.7 ft
3
MS-15SD2 1.27 ft (36L) 2.12 ft
3
– The suggested enclosure volumes are related to only one speaker, including woofer and duct(s)
displaced volume.
– For enclosures with more than one speaker, it is necessary to multiply the suggested volume and
duct(s) by the quantity of speakers.
ENCLOSURES INTERNAL VOLUME
CALCULATION INSTRUCTIONS
rECTanguLar BoX
A x B x C
Internal Volume =
1000
– A, B and C are internal dimensions.
VEnTED BoX
Duct(s) Diameter x Length
(32L) 1 2.95 in x 9.84 in (7.5cm x 25cm)
3
(32L) 1 2.95 in x 9.84 in (7.5cm x 25cm)
3
(48L) 1 3.94 in x 8.66 in (10cm x 22cm)
3
(48L) 1 3.94 in x 8.66 in (10cm x 22cm)
3
(60L) 2 3.94 in x 14.96 in (10cm x 38cm)
3
TraPEZoiD rECTanguLar BoX
(
C + D
A x B x
Internal Volume =
1000
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