Sub-Sat System Design

The exact configuration of a subwoofer/satellite loudspeaker system depends on a number of factors, such as:

•How large the room is and how many satellite speakers it will take to cover the room?

•Whether the distance between the satellite speakers allows a single subwoofer to cover the entire space?

•Whether the program material is light background music or dominant driving music?

•Where the subwoofer will be located in relation to room boundaries (wall, ceiling, corners)?

The system recommendations in this guide and the performance figures are based on some baseline assumptions which will not be correct for all applications. Adjustments may need to be made. A discussion of the considerations, baseline assumptions conditions and

possible adjustment requirements is below.

General Objectives

Sensitivity Balance

The volume balance between the subwoofer and the satellite speakers in a passively crossed-over system is called sensitivity balance.

Targets:

a)Sensitivity Balance – Typically, the way the human hearing system works, the subwoofer needs to be 2 to 6 dB louder than the satellite speakers in order to sound

balanced. The subwoofer/satellite systems in this guide are all structured to provide the proper range of sensitivity balance with the subwoofer located on a flat surface (wall, ceiling, floor). The sensitivity balance can be altered, as required, via an active graphic equalizer. The balance can also be altered by placing the subwoofer closer to more boundary surfaces -- see the “Subwoofer Location” section below for more about the effect of positioning.

b)Maximum Sound Level Balance – It is desirable for the subwoofer to be able to deliver adequate maximum sound output capability to keep up with the satellite speakers when they are driven at their maximum drive level. The subwoofer output of these systems is high enough to keep up with the satellite speakers at high drive levels.

Subwoofer Model Selection

All the systems in this guide use the Control SB-210 subwoofer, with the exception of the CCS6000 System, which uses the Control SB-2 subwoofer. Passive crossover networks are built-into SB-2 and available for SB-210, making it easy to structure subwoofer- satellite systems.

Designing for Other JBL Subwoofer Models

Other subwoofers from JBL Professional include Control 19CS In-Ceiling Subwoofer and Control 312CS High Power In-Ceiling Subwoofer. These subwoofers are intended to be used in actively crossed-over systems -- either contains a built-in passive crossover network.

For determining the proper number of Control 19CS subwoofers, use the Subwoofer Utility in the DSD Distributed System Design software (free download located on the Software Download page from the www.jblpro.com website).

For The Control 312CS subwoofer, use the “Control 300 Subwoofer Ratio Guide” posted in the Control 300 section of the Technical Library page on www.jblpro.com website.