JBL LSR28P Studio Monitors (Pair)
This vintage pair of LSR28P Monitors is fully functional and in good condition. Minor cosmetic wear around the edges as seen in the photos. These are heavy - about 50 lbs each.
The LSR28P Linear Spatial Reference Studio Monitor combines JBL’s latest in transducer and system technology with recent breakthroughs in psychoacoustic research to provide a more accurate studio reference.
The Linear Spatial Reference (LSR) philosophy is based on a set of design goals that carefully control the overall performance of the system in a variety of acoustic spaces. Instead of focusing on a simple measure such as on-axis frequency response, LSR designs require much better control over dispersion via transducer selection and crossover frequency design. Critical decisions of image placement, EQ, balance and timbre are typically made within +/- 15° vertically and +/- 30° horizontally. This workspace is where the engineer, producer and artist make critical mixing decisions and this is the area that LSR is optimized for superb in room response. By incorporating LSR into the system design requirements, placement rules are relaxed, a more stable stereo image is maintained and off-axis coloration is minimized.
The 8” woofer is based on JBL’s patented Differential Drive technology. With dual 1.5” drive coils, power compression is kept to a minimum to reduce spectral shift as power levels increase. An added third coil between the drive coils acts as a dynamic brake to limit excess excursion and reduces audible distortion at maximum levels. The cone is made of a carbon ﬁber composite forming a rigid piston and is supported by a soft butyl rubber surround.
The high frequency device is a 1” composite diaphragm integrated with an Elliptical Oblate Spheroidal (EOS) Waveguide with 60 x 100 degree dispersion which is critical to the smooth spatial response required in today’s working environments.
The LSR28P combines two high power ampliﬁers with an active crossover system which includes over 250 watts of continuous low frequency power and 120 watts for the high frequency. Active crossover circuitry results in a 36 dB/Octave Linkwitz-Riley Electroacoustic response between low and high frequency devices for smooth transition in both the frequency and time domains. This results in exception imaging and a lack of time smear. User adjustments include level calibration for setting with professional and semiprofessional equipment as well as ﬁne tuning of levels with variable level trim. XLR and 1/4” input connection can be accommodated as well as balanced and unbalanced signals. The frequency response of bass and treble amplitudes can also be adjusted to compensate for placement and room absorption characteristics.