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HLA-CB (Connecting Bar) HLA-CA, HLA-LB, and HLA-WHEELS
Connecting Bars and Lifting Bars are both black I-shaped aluminum bars that are 2.5 inches (6 cm)
tall, 3/16 inches (5 mm) thick and 34 inches (86 cm) long. Lifting Bars and Connecting Bars are sold by JBL in
pairs. Shipping weight is 7 lbs. (3 kg) per pair.
Speaker input signals: the system controller
The recommended system controller is the DSC280 Digital System Controller, which provides
processing for a stereo HLA speaker system. It is factory-loaded with presets that include the correct adjustments
for several different array configurations. The DSC280 is two rack-spaces (3.5 inches) high, 14 inches (36 cm)
deep and weighs 16 lbs. (7 kg). (See Section 3, “Using System Controllers”).
The back panel of the DSC280 has 2 female XLR input connectors, and two sets of four male XLR
output connectors, one for each band pass of a stereo system, for a total of 8 male XLR outputs. If the DSC280 is
located close to the power amplifiers, 8 short XLR cables will connect them.
If the DSC280 is located at a control position removed from the amplifiers’ location, 8 balanced (3-
wire) cables are needed to connect them. This can be accomplished using 8 XLR return lines in the microphone
snake, or preferably by using a separate, dedicated multi-pair cable with at least 8 channels total, terminating
inside the racks with XLR connectors.
A stereo HLA system requires 8 distinct channels of amplification, two channels for each band-pass
output. The subs, lows, midrange and high-frequency amplifier channels should be able to cleanly provide a
minimum of 1,600, 2,400, 1,600 and 800 watts respectively into four ohm loads. Three stereo amplifiers with
sufficient power, one each for lows, mids and highs, will work with eight 4895 three-way speakers, driving four
16-ohm transducers on each channel. Two additional amplifiers will power four 4897 subs, with two 8-ohm
transducers on each channel. Five amplifiers running 4-ohm loads can power a basic HLA block of eight 4895
speakers and four 4897 subs if the amplifiers can provide the required power for each type of transducer (See
Section 4, “Matching transducers to power amplifiers”).
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