600 MANUAL/vs2.QXP 7/28/98 11:47 AM Page 8
frequencies. Because the 600GTi arecrossover points away from the rangeSpeaker Break-In
specifically designed for midbasswhere your hearing is most sensitive.
frequency operation, in a 4-way system asTherefore we recommend that you try toThe 600GTi Woofer/Midbass uses
described they should have their low andkeep the low-pass frequency belowmany high strength materials which benefit
high frequencies blocked by an active or250Hz. This lets your full-range systemfrom a break-in period to achieve top per-
passive bandpass crossover in order toreproduce the frequencies covering theformance. The 600GTi will reach maximum
achieve the best system fidelity and themost important vocal and lead instrumentperformance after playing for about one
widest dynamic range.fundamentals and their harmonics, whichhour at a moderate volume level.
For the best performance, wewill help optimize imaging.
recommend that an active crossover withIf you prefer to use all passiveA Note on Power Handling
a minimum of 12dB per octave slope becrossovers, you will need to construct or
used for the transition point between thepurchase a band-pass filter for the desiredAs a result of their high efficiency,
Subwoofer and the 600GTi. The optimummidbass frequency range and install it in-all JBL loudspeakers will produce reason-
crossover frequency for this transition isline ahead of the 600GTi. Although theable volume levels in the automotive
environment using very little amplifier
dependent on the specific componentswide range and smooth roll-off of thepower. However, the use of a low-powered
used, the vehicle, and other installation600GTi allows the use of a simple 6dB peramplifier to attain very high volume levels
details. As a general rule, the crossoveroctave filter, for the best system dynamiccould lead to overdriving the amplifier. This
frequency should be as low as possiblerange, we recommend that a minimumwill generate high distortion levels which
to achieve the best system imaging. slope of 12dB per octave be used.Youcan easily damage loudspeakers, even if
can fine-tune the crossover after theThe most advanced system designsthe rated power of the amplifier is below
installation is complete for the best sound.use active electronic crossovers such asthe rated maximum power handling of the
A good place to start your tuning processthe JBL GTX2, GTX4 or GTX47 at both theloudspeaker!
is approximately 50Hz for the subwoofersubwoofer to midbass transition point andAs a general rule, do not turn up the
to midbass high-pass crossover point.at the midbass-to-midrange transition. Thevolume control past the point where you
Higher crossover frequencies will allow themaximum recommended RMS amplifierhear distortion in the form of either signal
speaker to play louder. Since no crossoverpower routed directly to the 600GTidistortion from an overdriven amplifier or
is perfect, it is advisable to keep youris 300 watts.
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