Building Blocks to Clear Sound

It takes more than an accurate speaker system to have accurate response at the mix position. The key to accuracy is tackling the effect of boundaries, standing waves and reflections. In developing the LSR Series Studio Monitors, JBL examined each problem in the environment and created the perfect solution. Even if you work in a small control room, an LSR Series Studio Monitor system will provide smooth accurate response at the mixer's chair.

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LSR Linear Spatial Reference Design and Measurement

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 measurement such as on-axis frequency response, JBL measures systems in a field 360 degrees around the speaker and engineers the entire system to ensure off-axis response reflected to the mix position is also smooth and accurate.

We all know that many loudspeakers have similar measurements but sound different. By going beyond simple on-axis frequency response measurements, JBL defines the ultimate performance specification for new systems – what it will sound like in your room. At the mix position, you hear a combination of direct sound and sound reflected from the rooms surfaces. For sound arriving at the mix position to be smooth and neutral, it is not enough for a speaker to measure “flat” on-axis - it is essential the speaker have excellent off-axisperformance. While other manufacturers use a single on-axis frequency response measurement taken at one point in space, JBL measures monitor systems over a sphere that encompasses all power radiated into the listening room – in every direction. This data reflects 1296 times the information of a single on-axis response curve. Seventy-two measurements of the direct sound field, the reflected sound field, and the reverberant field, the entire sound field heard by the listener, is correlated to optimize response at the listening position. In place of spectral smoothing used by some manufacturers, which actually conceals data, the JBL approach actually exposes flaws in systems, such as resonances, poor dispersion and other causes of off-axis coloration. The data shown below is a set of spatially measured graphs that are the heart of JBL’s philosophy.

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RMC™ Room Mode Correction

A JBL first, the RMC™ Room Mode Correction system is included in the LSR6300 and LSR4300 Series models. The RMC system includes everything needed to analyze and compensate for low frequency problems providing exceptional accuracy at the mix position. Room modes or standing waves can mislead you give you a false impression of low frequency content in the mix. JBL is first to supply a complete solution for identifying and overcoming the negative effect of room modes.

The LSR 6328P,6312SP and all LSR4300 models are equipped with RMCT, JBL's ingenious Room Mode Correction System. The LSR6300 RMC Calibration kit includes everything needed to identify room modes and set the LSR6300 series on-board parametric equalizer.JBL engineers took the RMC solution one step further by equipping the LSR4300 Series speakers with an automated analyzer and corrective filter.Both systems dramatically improve low frequency performance at the mix position.

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Built-in Boundary Compensation

With the advent of multi-channel production, trying to find a place for more speakers, and space limitations, may demand the positioning of the speaker be compromised. JBL's powered models include boundary compensation switches that can be used to offset the increase in bass-response, which occurs when the speaker is placed near a wall, in a corner or on a work surface. Simply set the switch which corresponds to your condition and flat response is restored.

With the advent of multi-channel production, trying to find a place for more speakers, and space limitations, may demand the positioning of the speaker be compromised. JBL’s powered LSR6300 Series models include boundary compensation switches that can be used to offset the increase in bass-response, which occurs when the speaker is placed near a wall, in a corner or on a work surface. Simply set the switch which corresponds to your condition and flat response is restored. The LSR4300 Series also has boundary compensation features. The LSR4300 Automated RMC System is designed to tackle problems caused by boundaries or room modes. The addition of an LSR4312SP Subwoofer doubles the power of the LSR4300 RMC System, allowing the subwoofer to address low frequency problems caused by room modes, and freeing the LSR4328P and LSR4326P monitors to address any boundary conditions that exist.