Jbl lsr28p manual

The LSR28P is certainly capable of generating powerful sound pressure levels up to dB SPL, apparently without obvious signs of distortion or fatigue — in fact, distortion levels are extremely low throughout the frequency range and even at high levels, which is a very good sign of a competent loudspeaker.

These monitors don't sound loud even when they are being driven hard, which can be a problem when you try to have a conversation with someone, and is a sure indication that distortion levels are extremely low! The overall sound balance is commendably flat, and the plots show the frequency response to be extremely accurate, although I detected a slight tendency towards 'pluminess' in speech, particularly on female spoken and singing voices. Although I wasn't able to make direct comparisons of the JBL against the ATC or Dynaudio active equivalents, I would imagine choosing between them would depend very much on a personal assessment of the finer nuances of tonal balance rather than on any obvious technical differences.

I would happily give these JBLs space in my monitoring system, and that's the second time I've made the same comment about JBLs in the last six months! If you are considering upgrading your monitoring system in the near future I would definitely recommend giving the LSR28Ps a careful audition alongside your other favourite active systems.

The idea is that, as the coil is moved in a magnetic field, induced currents create their own magnetic field which opposes the original, thus acting like a dynamic brake, and limiting the maximum cone excursion. This has the benefits of protecting the driver from abuse without adding to the distortion figures at high sound levels. Clever design of the magnetic core of the drive unit means that the magnetic flux is guided around a neodymium magnet assembly such that it passes through the two driven coils in opposite directions.

As the coils are wired in opposite polarities, their mechanical efforts combine to equate to a conventional single coil, moving the speaker cone as required. Although this approach initially appears unnecessarily complicated, JBL have claimed a number of advantages for it.

First, since there is double the surface area of coil, heat dissipation is far better, allowing a 3dB increase in power handling and a reduction in dynamic compression. Second, because the two coils are wired in opposite phases, their mutual inductance is reduced, presenting an easier load to the amplifier.

The additional shorted coil in the middle of the assembly does nothing for most of the time, as it remains well away from the two magnetic circuits. However, during large cone excursions this third coil begins to enter a magnetic field and the induced current sets up an opposing magnetic force acting against the motion of the cone, progressively damping its movement. Pros Easy interfacing. Good room equalisation options. Excellent stereo imaging and depth presentation.

Page 2 2. Page 3 2. Page 4 2. Page 5 2. Page 5 3. JBL designed the entire system starting with the materials and topologies of the individual transducers, through to the final assembly of the diecast parts.

Page 6: Getting Started 2. Covered here is a typical stereo setup for near to mid field monitoring. Page 7: Audio Connections Angling towards the listening position: LSR monitors should be angled to directly face the listener. The center of the high frequency transducer should be on-axis with the ear level of the listener. It must always be connected to the electrical installation safety ground. The LSR units have carefully designed internal grounding and bal- anced inputs and outputs to reduce the possibility of ground loops hum.

If hum occurs, see Appendix A for suggested audio signal wiring and system grounding. Page 9: Lsr32 3-Way Monitor Section 3. Cable runs exceeding 10 meters 30 feet should be made with heavier wire, 12 or 10 AWG. With dual 1. The LSR units have carefully designed internal ground- ing and balanced inputs and outputs to reduce the event of ground loops hum.

If hum occurs, see Appendix A for suggested correct audio signal wiring and system grounding. Page Low Frequency Adjustments 4.

The active drive circuitry has been developed to maximize the acoustic output power while maintaining overall low distortion and high transient performance. It must always be connect- ed to the electrical installation safety ground. The LSR units have carefully designed internal grounding and balanced inputs and outputs to reduce the event of ground loops hum.

Page Low Frequency Characteristics 5. At the crossover point between the subwoofer and satel- lite speakers, it is important that all systems are in the correct polarity.

If the subwoofer and the satellite woofers are in the same vertical plane, the polarity should be set to normal. Page Led Indication 5. This indicates that the high pass filters on the three outputs are bypassed and the subwoofer feed is from the discrete input. JBL product may differ in some respect from its published description, but will always equal or exceed the original design specifications unless otherwise stated.

On-Axis Response 2. First Reflection Sound Power 4.