JBL LSR305 Owner's Manual - Section 2: Introduction
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Section 2: Introduction
Congratulations on your purchase of JBL Professional 3 Series Studio Monitors. These studio monitors 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 reflected 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 more than 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 Wave Guide
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 benefit,
incorporating this wave guide, 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.
LSE305 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 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 fingers 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-flared shape of the port is precisely engineered for
greater low-frequency extension and reduced turbulence.
•Bi-amplified Design with individual power amplifiers for the Low Frequency and High Frequency
Transducers. The design utilizes efficient high-output Class D integrated power amplifiers 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 reflective or absorptive listening
environments.
JBL Professional Reliability
Prior to becoming a production-ready design, each 3 Series model is subjected to JBL’s tough 100 hour
power test, in which the speaker is required to play continually at full output for 100 hours without failure. This
demanding test ensures your 3 Series speakers will deliver years of reliable performance.
To get the most out of your JBL 3 Series Studio Monitors, please review this owner’s manual and keep it on
hand for future reference. Also, please register your new speakers at www.jblpro.com/registration.