Harman JBL MS-15SD2 - Manual (Page 3)

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You must use both coils of a dual voice-coil woofer connected 2.
either in series or in parallel.
Most amplifiers deliver exactly the same amount of power bridged 3.
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:
The total system impedance of woofers in parallel can be calculated 1.
using this formula:
Impedance =
1
w
1
+ 1
w
2
+ 1
w
3
...
1
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
1
+ w
2
+ w
3
...
The diagrams below show parallel and series speaker connections.
Figure 1. Parallel connection Figure 2. Series connection
SUGGESTED ENCLOSURES
MoDELS SEaLED BoX VEnTED BoX
Internal Volume Internal Volume Qty. Duct(s) Diameter x Length
MS-10SD2 0.78 ft 3 (22L) 1.13 ft 3 (32L) 1 2.95 in x 9.84 in (7.5cm x 25cm)
MS-10SD4 0.78 ft 3 (22L) 1.13 ft 3 (32L) 1 2.95 in x 9.84 in (7.5cm x 25cm)
MS-12SD2 0.95 ft 3 (27L) 1.7 ft 3 (48L) 1 3.94 in x 8.66 in (10cm x 22cm)
MS-12SD4 0.95 ft 3 (27L) 1.7 ft 3 (48L) 1 3.94 in x 8.66 in (10cm x 22cm)
MS-15SD2 1.27 ft 3 (36L) 2.12 ft 3 (60L) 2 3.94 in x 14.96 in (10cm x 38cm)
– 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 TraPEZoiD rECTanguLar BoX
Internal Volume = A x B x C
1000 A x B x
( C + D )
1000
2
Internal Volume =
– A, B and C are internal dimensions.