The LSR4328P series automatically analyzes the frequency response of the speakers at the listening position and automatically applies a corrective filter to minimize low frequency resonance. When the calibration mic is connected and the RMC analysis is initiated, the LSR4300 RMC system applies a parametric filter at any of 73 frequencies (1/24th octave centers) between 20 Hz and 160 Hz, with a variable Q from 1 (1.4 octave bandwidth) to 16 (1/11th octave bandwidth), with 3 to 12 dB of attenuation.During the RMC calibration process, speaker levels are trimmed in 0.25 dB increments so that all speakers in the system produce equal SPL (sound pressure level) at the mix position.
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. 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.
