JBL Discover the Features and Performance of the LSR6312SP Powered Subwoofer

LSR6312SP Powered Subwoofer System

The LSR6312SP Active Subwoofer consists of a Neodymium Differential Drive NDD™ 12" neodymium woofer integrated with a powerful 260 watt continuous power output amplifier. The active drive circuitry has been developed to maximize the acoustic output power while maintaining overall low distortion and excellent transient performance. The enclosure is manufactured with a molded baffle and rigidly braced MDF enclosure for low resonance and minimal box loss. The Linear Dynamics Aperture (LDA) Port design minimizes port turbulence and eliminates port compression.

Active crossover electronics supply 4th-order electroacoustic slopes to the low pass subwoofer transition to reduce the possibility of audible localization of the subwoofer. This allows greater flexibility in placement for optimum operation in a wide variety of rooms. Since low frequency energy supplied by the LSR6312SP is essentially omnidirectional, placement of the unit(s) is more dependent upon room acoustics and interaction than localization issues.

The active electronics includes switchable high pass filters for the front satellite speakers. This option is used to filter low frequency information from the front speakers and redirect this information to the subwoofer. This is usually the case when the front speakers cannot reproduce extended low frequency information at the desired sound pressure level, or to optimize the low frequency perform- ance of the system in the room. Alternatively, if the front channels are operated in full range, the bypass function can be enabled allow- ing the subwoofer to be muted. The bypass function allows the LSR6312SP direct LFE input to remain active.

RMC Equalization

There are three screwdriver adjustable controls on the rear panel of the LSR6328P indicated RMC. The term RMC stands for Room Mode Correction, which consists of a single section cut-only parametric equalizer that can be adjusted in frequency, width (Q) of cut, and the amount of cut. It is used to reduce the magnitude of any dominant low frequency peak in response due to standing waves at the listening position. Details of Room Mode Correction are presented in the user guide included with the RMC Claibration Kit.

Audio Connections

The LSR6312SP subwoofer contains both input and output XLR connectors for three channels, which are typically Left, Center and Right. An additional direct input is included which is active at all times. It This allows routing for a separate signal directly to the input electronics of the LSR6312SP, as well as the summed low frequency response of the Left, Center and Right inputs. The inputs are shipped with a sensitivity of -10 dBV, but this can be changed +0, +4 dBu, +8 dBu or +12 dBu by moving a dip switches on the back of the unit. A 12 dBu variable input trim can be switched in to calibrate input sensitivity to a precise setting. The outputs transmit either full range or high-passed program information, depending on the mode of the subwoofer. The summed output transmits a sum of the L, C, R and Direct input signals with no processing to allow chaining of multiple LSR6312SP subwoofers. Positive voltage to Pin 2 of the XLR will produce a forward motion in the low frequency cone. Shown below in Figures I and J are views of the rear electronics panel on the LSR6312SP and a signal flow diagram for the system. We recommend that you study these drawings in detail.

Figure I

With Differential Drive® Transducer Technology	Sensitivity
U.S. Patent Nos. 5,748,760 and 5,828,767	+10 dB
Other U.S. and Foreign Patents Pending
	0 dB

Input Option Active

Trim With Switch Up

			Cut 0
Left In	Left Out	Center In Center Out Right In Right Out	Sub-Direct In	dB
	LSR6312SP		Input Trim Active
			+4 dBu Input Sensitivity
	Linear Spatial Reference		+8 dBu Input Sensitivity
			Signal Polarity Inverted

Powered Subwoofer	-4 dB Bass Alignment
	RMC Defeat

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