The D-fend SA300 keep your system safe but your venue and audience as well. With D-fend there are no more worries about blown speakers HF drivers or crossovers. Or even worse: fire caused by excessive heat. The user simply sets the thresholds and D-fend monitors and limits the amount of input power it passes through to the loudspeaker. It’s USB compatible and can be programmed to your specifications from a desktop or laptop. Just set it and forget it. Protect your products venue customers and your reputation with the first passive speaker protection system that is virtually indestructible.Features DIGITAL SIGNAL PROCESSING With on-board digital filtering D-fend provides multiple frequency dependent thresholds and independent attack/release timing parameters. DIGITAL ATTENUATION Significantly reduced heat no bulbs no light output. FULLY PROGRAMMABLE On-board microprocessor allows user attack release and threshold settings to maximize loudspeaker performance. HIGH POWER Capable of protecting high power woofers and sub-woofers from over-power conditions as well as mechanical damage thresholds. VERSATILE Allows damage-free operation of woofers tweeters and/or midrange devices. NO AUXILIARY POWER Operates from a standard speaker-level signal does not require auxiliary power except for low-power applications. MUSICAL Attenuation slewing algorithms provide lamp-like musicality without the nuisance of light and flammability concerns. - SKU: TBALL13467