Crossover Settings and “Bass Management”
“Bass management” is a term that refers to the practice of using a subwoofer to reproduce the bass frequencies of the main channels. Because of the physiology of the human ear, low frequencies are largely non-directional. Given an adequate listening distance, we can’t easily tell where bass signals are coming from. Thus, it makes little or no difference to the listening experience whether the bass component in a sound comes from the originating speaker (which may be off to your left or right, or even behind you) or from a dedicated subwoofer which is better equipped – and better positioned in the room – to reproduce low frequencies than even a full-range monitor. For that reason, you may want to use an LSR310S subwoofer to reproduce all the bass frequencies in your system. If you are using an LSR310S Subwoofer in your system, bass management is accomplished simply by routing your Left and Right mix channels to the Subwoofer inputs and then from the subwoofer outputs to the Left and Right speakers. The frequency at which the subwoofer divides signals to the sub and the left and right speakers can be set using the Crossover Frequency selector switch on the input panel of the LSR310S Subwoofer. The 80Hz filter setting is recommended when the goal is a full range reference monitor system that accurately portrays content below the cut-off of the main speakers. The 80 Hz crossover provides a smooth transition and between the subwoofer and the main speakers, while optimizing the blend of low frequency in the system, without audible localization of bass, creating the perception of a full range system with no subwoofer. To produce a smooth transition between the speakers and the subwoofer and the goal is an accurate representation of frequency response in the program material. Two additional settings are provided: XLF and External. XLF A trend in music production is the requirement for enhanced low frequency response in the control room. Artists and producers involved in the production of dance music appreciate the ability to audition their work as it might sound when played on a system with enhanced low frequency tuning, commonly employed in dance clubs. A JBL first, the LSR310S includes a special XLF Extended Low Frequency setting that emulates the response curve applied to a club playback system. When the XLF crossover setting is selected, a 120Hz High Pass Filter is engaged in conjunction with a 10 dB boost at 60Hz with a bandwidth of 0.5 octaves. Using this setting, the bass output more than doubles and the character of low frequency approximates that of a club system. Continuous low frequency with very high peak SPL is made possible by JBL’s new long excursion low frequency driver working in concert with JBL’s patented Slip Stream™ Port design, and powered by a 200 Watt class D amplifier. A protective circuit allows the 310S to continuously produce low frequency at high output without failure. In situations where positioning will allow, an additional 6 dB of output can be achieved by positioning the LSR310S subwoofer adjacent to a wall or at the intersection of two walls.
