GT Series Owners Manual 5/14/99 9:49 AM Page 3
Connecting Your Subwoofer to Your2. You may connect the coils of a dual-To design a subwoofer system thatFigure 2. Series connection
AmpliŢervoice-coil woofer in series, but NEVERmaximizes available ampliŢer power,
JBL GT Series subwoofers are available connect separate woofers in series.keep the following rules in mind:
in three different conŢgurations: single Because the ampliŢer-damping factor1. The total system impedance of
4-ohm voice coil, single 8-ohm voice coil(the ampliŢerOs ability to control thewoofers in parallel = 1/(1/w1 + 1/w2 +
and dual 4-ohm voice coils. Depending motion of the woofer) is expressed as1/w3...) where w is the nominal imped-
on the ampliŢer you are using, you maya ratio of terminal impedance (the sumance of the woofer.
use either single- or dual-voice-coil of speaker impedance, wire resistance2. The total system impedance of voice
subwoofers in singles or multiples toand the D.C. resistance of anycoils (or woofers) in series = w1 +
maximize the power available from yourcrossover coil connected to thew2 + w3...
ampliŢer. To achieve the maximumwoofer) to ampliŢer-output imped-
ampliŢer output possible, you shouldance, connecting woofers in seriesThe diagrams below and at right show
design a speaker system that provides reduces the damping factor of theparallel and series speaker connections.
the lowest impedance that your ampliŢerampliŢer to a value less than 1. This
is rated to drive safely. When designing will result in poor transient response.Figure 1. Parallel connection
a subwoofer system, abide by the 3. You must use both coils of a dual-
following rules:voice-coil woofer either in series or in
1. DonOt mix different subwoofer or enclo-parallel.
sure types in the same system (use all4. Most ampliŢers deliver exactly the
single-coil 4-ohm woofers, all single-same amount of power bridged into
coil 8-ohm woofers, or all dual-coila 4-ohm load as they do running a
woofers).2-ohm stereo load.
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