AC Power Connections, Audio Level Adjustment

Input Trim Active

LSR6312SP Powered Studio Subwoofer System

AC Power Connections

The LSR6312SP power supply voltage is internally set at the factory for 100-125V or 200-250V. The ground terminal of the IEC plug is required by wiring codes and regulations. It must always be connected to the electrical installation safety ground. The LSR6300 Series electronic units have carefully designed internal grounding and balanced inputs and outputs to reduce the likelihood of ground loops.

Audio Level Adjustment

Switch 1 enables the Input Trim pot. With the switch in the down position, the trim control is out	Figure K
of the circuit and does not affect the input sensitivity. In the up position, the input trim is added
to the circuit and will attenuate the input level from 0 - 13 dB.

•Switch 2 changes the nominal sensitivity of the LSR6312SP L, C, R and Direct inputs to +4 dBu.

•Switch 3 changes the nominal sensitivity of the LSR6312SP L, C, R and

Direct inputs to +8 dBu.

•+4 dBu Input Sensitivity

Use of Switch 2 and 3 together changes nominal input sensitivity to +12 dBu. +8 dBu Input Sensitivity

Low Frequency Adjustment

Signal Polarity Inverted

-4 dB Bass Alignment

RMC Defeat

Switch 4 reverses the polarity of the LSR6312SP. At the crossover point between the subwoofer and satellite speakers, it is important that all systems be in correct polarity. If the subwoofer and the satellite woofers are in the same vertical plane, the polarity should be set to normal. If the subwoofer is not in the same plane as the satellites, the polarity may need to be reversed. To check this, put on a recorded track that has a good amount of bass and switch between the two positions. The setting that produces the most bass should be the one to use.

Boundary Compensation: The low frequency response of the LSR6312SP can be adjusted to compensate for placement near boundaries in the room. Bass frequencies below 80 - 90 Hz are essentially omnidirectional. Positioning subwoofers in corners or against walls will increase the in-room efficiency of the system allowing greater apparent output. Placing subwoofers against wall boundaries will also reduce frequency response variations due to cancellation interference. The Bass Alignment switches compensate for subwoofer location by adjusting the amount of low frequency power generated below 50 Hz.

Using a sound level meter, a technique that has been used successfully is to put the subwoofer in the listening position and move the meter or yourself into possible subwoofer locations. Finding the positions with the greatest low frequency energy can quickly be found. After you find a couple of possibilities, move the subwoofer into one of these locations and evaluate it.

•Switch 5 reduces the level below 50 Hz by 4 dB. This position is designed to offer maximally flat response when the LSR6312SP is placed at the intersection of two boundaries such as a floor and wall.

•Switch 6 disengages the RMC function.

LCR Bypass: The 1/4" jack used for LCR bypass and discrete selection operates with a simple dry contact closure between the tip and sleeve of the jack. This function can be controlled remotely by using a tip-sleeve plug and two conductor cables, and shorting the two conductors together using a simple remote switch. The sleeve of this connector is tied to audio ground, so care should be taken to avoid ground loops when using this option.

LED Indication

A multicolored LED indicator is located on the front of the LSR6312SP. In normal operation, this LED will be GREEN. When the LSR6312SP is in Bypass mode, the LED will turn AMBER. This indicates that the high pass filters on the three LCR output are bypassed and that the subwoofer feed is from the direct alone. At the onset of amplifier limiting the LED will flash RED. Continuous RED flashing of this LED indicates that the levels should be reduced.

RMC Equalization

RMC Room Mode Correction is used to reduce the effects of unfriendly standing waves at the mix position. There are four screwdriver adjustable controls on the rear panel of the LSR6312SP indicated RMC. These enable the width, frequency and depth adjustments to be made when using RMC. The make-up gain control is used for making an overall adjustment for approximately equal loudness for com- parisons with and without the RMC function. Details of operation are covered in the User Guide included in the RMC Calibration Kit.

LSR6300 specifications

The JBL LSR6300 series of studio monitors is renowned for its exceptional sound quality and precision, making it a preferred choice for both professional studios and passionate audiophiles. With advanced technologies and meticulous engineering, the LSR6300 series delivers a clear, accurate listening experience that is vital for mixing and mastering.

One of the standout features of the JBL LSR6300 is its Image Control Waveguide technology. This innovation ensures not only a wide sweet spot but also excellent off-axis performance. This means that no matter where you are positioned in relation to the speakers, you'll receive a balanced and consistent sound. This technology allows for an even distribution of sound across the audio spectrum, making it easier for engineers to make informed decisions about their mixes.

In terms of drivers, the LSR6300 series boasts high-performance woofers and tweeters that are specifically designed to provide an extended frequency response. The 8-inch woofers replicate low frequencies with impressive depth, while the 1-inch neodymium tweeters deliver crisp high frequencies without introducing distortion. The result is a full-range output that captures the nuances of any audio material.

Another notable characteristic is the room tuning controls on the back of the monitor. These controls enable users to optimize the sound output based on the acoustic environment of their studio. By adjusting the low-frequency and high-frequency settings, you can compensate for any acoustic anomalies in the room, ensuring your mixes translate well to other playback systems.

Furthermore, the LSR6300 is equipped with JBL's patented Slip Stream port design. This rear-firing port minimizes turbulence and enhances low-frequency response. The design ensures that bass notes are rendered with clarity and punch, allowing for a dynamic listening experience without excessive boominess.

The robustness of the LSR6300’s construction is also noteworthy. With a solid enclosure that reduces resonance, the monitors are built to withstand the rigors of daily use. The sleek, professional appearance adds to their appeal in any studio setting.

In conclusion, the JBL LSR6300 series integrates advanced technologies and thoughtful design elements, making it an exceptional tool for audio professionals. With its accurate sound reproduction, flexible room control options, and thoughtful engineering, the LSR6300 continues to set a high standard in the field of studio monitoring.