Installing A Passive Radiator
A passive radiator (unclions like a port.
II can be used, where battle space permits, to tune an enclosure to very
low frequencies by varying the number of weights attached to the cone
assembly. A passive radiator should be used only with the specific low
frequency loudspeakers for which it is recommended.
The passive radiator must be installed with the loudspeaker in an airtight
enclosure of the recommended internal volume. Mounting dimensions
are the same as for the loudspeaker. For optimum performance, place the
two units side by side; however, they can be mounted in any configuration
as long as they are no closer than two inches (50 mm) to each other, and
not separated by more than six inches (150 mm). Two removable metal
discs are attached to the center of the PR15C The fiberboard disc in fronl
of them is integral to the passive radiator and must not be removed. Each
of the metal discs weighs 100 grams. Six fiberboard discs are supplied in
the carton; each of these weighs 20 grams.
The passive radiator must have the proper mass in order lo tune an
enclosure to Ihe resonant frequency of the low frequency loudspeaker. This
chart provides a guide to the use of the PR15C in its usual applications.
Tuning Chart for PRI5C
Install Iho number of discs indicated tor the
enclosure volume Cm = metal disc I = liberboard disc)
Enclosure
Volume
Ures
GUSC
=081
113
HI
142- 16D
5
1
-St)
170- jjjg
•QS-??b
7- B0
Used with
LEMH.LE15H
3t
21
11
o-
Used with
12-11! 136H
1
m • • (
1m
_
_
•Da
noi ristai mvoJÙW scre.v
Tuning
A
Passive Radiator
When adding or removing luning discs, be certain lhat the hardware is in ihe
sequence shown Tighten Ihe machine screw only enough lo hold Ihe discs and
washers snugly in place.
