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Section 2: Introduction
Congratulations on your purchase of JBL Professional 3 Series Studio Monitors. These studio monitors and
Subwoofer meet JBL’s high standards for accuracy and long-term reliability in demanding professional
applications. All 3 Series models incorporate JBL Professional transducer and network technologies to provide
accurate frequency response, exceptional low frequency extension and high SPL capability. JBL LSR Linear
Spatial Reference design ensures greater accuracy at the mix position in acoustically varied work spaces and
production environments. Additionally, each speaker is equipped to interface with a range of signal
sources including high-output professional equipment.
JBL LSR Linear Spatial Reference Design
Because listening environments vary, JBL designed the 3 Series system using LSR Linear Spatial Reference
design criteria that improve accuracy at the listening position in a broad range of rooms. The key to accuracy is
ensuring not just the on-axis sound, but also the reected sound reaching the mix position is neutral. While most
manufacturers take only a single on-axis measurement of the speaker’s performance, Linear Spatial Reference
design criteria requires 72 measurements, 360 degrees around the speaker, yielding 1,200 times more data. This
data is used in the design of critical system components, enabling JBL to engineer complete systems that deliver
smooth off-axis response. The result: clear accurate sound at the listening position in any room.
3-Series Image Control Waveguide
JBL’s revolutionary Image Control Waveguide gives the LSR305 and LSR308 remarkable imaging, a wide
sound-stage, and a solid “phantom center.” Subtle details can be heard, even in a dense mix. As an added
benet, incorporating this waveguide, 3-Series models give you a broad “sweet-spot” in your work space,
so you don’t have to be seated directly in front of the speakers to hear accurate, natural and open sound.
3 Series models include a range of features to meet the needs of demanding audio production applications.
LSR305 and LSR308 models include:
• Low frequency magnetically-shielded transducers, equipped with 1.5" voice coils and robust motor structures to
provide excellent low frequency performance. By reducing thermal-related effects, the 3 Series Studio Monitors
and Subwoofer sound the same at low, medium and high levels. The woofers are magnetically shielded to prevent
interference with magnetically sensitive displays and equipment. The woofer’s self-repairing dust dome is resistant
to dents caused by ngers or external objects.
• JBL’s Patented Slip Stream
low frequency port design that works in concert with the woofer to produce deep
bass response at all playback levels. The double-ared shape of the port is precisely engineered for greater low-
frequency extension and reduced turbulence.
• Bi-amplied Design with individual power ampliers for the Low Frequency and High Frequency Transducers.
The design utilizes efcient high-output Class D integrated power ampliers to provide high SPL
(Sound Pressure Level) for demanding production applications.
• Soft dome magnetically-shielded high-frequency transducers with optimally damped materials to improve
transient response and minimize distortion. By reducing distortion in the lower operating range, where the
ear is most sensitive, these transducers reduce ear fatigue.
• Balanced XLR and 1/4" connectors, a dented level attenuator to allow interface to a broad range of signal
sources. The +4 dB / -10 dB input sensitivity switch allows connection of the speakers to high-output
professional equipment without danger of input overload.
• High Frequency and Low Frequency Trim controls in the LSR308 and LSR305 allow adjustment of frequency
response to preference, or to compensate for acoustically reective or absorptive listening environments.
Producing extended low frequency into the 20 Hz region, the LSR310S is the perfect match for the LSR305
and LSR308 Studio monitors. The LSR310S feature set includes:
• A custom designed down-ring, High-Excursion 10" woofer with an additional bucking magnet.
• 200 Watts Class D Power Amplier with abundant output and dynamic headroom for the most
demanding production styles.