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One Systems Introduces SF-4 Highpass Filter

One Systems, a Nashville-based designer and manufacturer of high-output direct-weather loudspeakers, is introducing the SF-4 analog high-order highpass filter system. The SF-4 offers a solution for audio systems that do not use digital processors or amplifiers with built-in DSP because of cost or complexity.

Every professional loudspeaker system—whether vented, sealed or horn-loaded—requires infrasonic filtering to deliver its optimum performance. The basic function of a highpass filter is to suppress low frequency signals that are below the loudspeaker’s tuning frequency. The SF-4 provides active filtering for both low impedance systems as well as high impedance/transformer based designs.

Filtering ultra-low frequency signals substantially improves loudspeaker reliability, increases power handling and also reduces system distortion. In addition to audibly improving a loudspeaker’s performance, highpass filters substantially increase the power amplifier’s headroom by reducing low frequencies that require significant power to reproduce.

The SF-4 occupies a single-rackspace (1.75-inch) all-metal chassis and is equipped with a balanced XLR-type input and two parallel balanced XLR-type outputs. The SF-4’s user selectable fourth-order Butterworth filter frequencies are 35 Hz, 45 Hz, 60 Hz and 80 Hz, and were carefully chosen to match the requirements of One Systems speaker models.

All of the SF-4’s controls are located on its back panel to minimize tampering with its settings. The unit features an IEC power connector for easy compatibility with local requirements as well as a two-position AC mains selector switch that enables it to work with line voltage/frequency anywhere in the world.

Because the SF-4’s analog circuitry and filtering promise the necessary infrasonic protection that every speaker needs, One Systems says that it can also be used with other manufacturers’ systems with the same benefits. One Systems can recommend filter settings for other manufacturers systems upon request.

The One Systems SF-4 offers a combination of necessary infrasonic filtering, simple operation, improved sonic performance, system reliability and high value. The company states that its well-designed analog circuitry and low noise will complement any sound system.

The SF-4 and other One Systems products will be on display at Prolight + Sound 2011 in Frankfurt, Germany (April 6-9) in Hall 8.0, stand # J 70E.

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