29
Finding the Tuning Frequency of a Passive
Radiator Subwoofer Box System (f
B
)
Finding the tuning frequency of a passive radiator
subwoofer box system (f
B
) is exactly the same procedure as
finding the tuning frequency for a ported box. Follow the
instructions for
Finding the Tuning Frequency of a
Ported Subwoofer Box System
on page 18.
Make sure
there is no amplifier connected or damage to the IM-SG
could occur!
Referring to Figure 5, f
B
represents the tuning frequency of
the system. This is the frequency at which the passive
radiator has the highest excursion and the active driver has
the lowest excursion.
To prevent excessive cone excursion and potential damage
to the subwoofer is it advisable to use a infrasonic
(subsonic) filter set around
octave below f
B
. To
calculate this, multiply f
B
by .707 Thus in this example 30
Hz X .707 = 21.2 Hz.
Summary of Contents for SMD IM-SG
Page 1: ...IM SG Impedance Meter Signal Generator Owner s Manual ...
Page 20: ...20 Figure 2 Impedance curve of a typical 4 ohm 1 tweeter Notice the fS at 1 59 kHz ...
Page 22: ...22 Figure 3 fC of a single 4 ohm 15 inch subwoofer in a 2 cubic feet sealed box ...
Page 44: ...44 Notes ...
Page 45: ...45 Notes ...
