Overview

Your Sunfire Subwoofer is designed to give you the best possible low-frequency sound quality for your home theater experience. It incorporates a tremendously powerful built-in amplifier to produce tight, floor-rumbling bass down to 18 Hz, that you can feel as well as hear.

The subwoofer has an adjustable high cut filter and speaker level and low level inputs for easy incorporation into existing systems, or as part of a subwoofer/satellite speaker combina- tion.

The Woofer

To have lots of bass requires moving lots of air. Your Sunfire True Subwoofer’s driver can move back and forth approximately five times more than a normal subwoofer. This gives it a lot of air moving capacity which allows for massive bass performance.

The Amplifier

The large movement range of the driver creates greater air pressure inside the box than a conventional woofer. Therefore, the drive amplifier must be much more powerful than an ordinary woofer amplifier. In fact, it has to be so powerful that it is almost hard to believe.

The power amplifier within your Sunfire True Subwoofer is capable of delivering over 1,250 watts into a 3.3 ohm resistor (the voice coil resistance of the subwoofer’s driver). When the same full output is applied to the driver, however, the enormous back-electromotive force generated as a consequence of its large motion and giant magnet causes the current flow to be much less than if it were a 3.3 ohm resistor. It is this singular property of the driver that allows the woofer to be approximately ten times more efficient than a woofer this size would normally be. Hence, the

actual average input power is substantially less than 1,250 watts, and is approximately 120 watts for most musical material on the loudest passages.

A compressor circuit kicks in automatically if the input signal level reaches a level that would overload the driver. This maintains a ceiling on the output without clipping.

If the input signal is driven even further, a ‘soft clipping’ circuit is enabled. This allows the woofer to put more sound into the room to satiate the power hungry user, but without distortion or damage to the woofer. Thus, for explosive scenes in movies, this produces extremely high sound pressure levels (SPL) in your room without the woofer banging against its mechanical stops.

If you would like more detailed information regarding the subwoofer design, please call us and we will send you a copy of our subwoofer technical white paper, or you can view it on our website: www.sunfire.com.

Note: In this manual, the term “sub/ LFE” is used to denote the subwoofer or Low Frequency Effects output, commonly found on home theater preamplifi- ers and receivers.

User's Manual

 

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