Q: How many D-fend units do I need for 2-way or 3-way enclosures?
D-fend is designed in such a way that you would only need one unit per amplified signal. In a 2-way or 3-way enclosure that is powered by one amplified signal, you will only need one unit. However, if you are bi-amping an enclosure, you will need two. Tri-amping will require three. In short, every amplified signal will require one D-fend unit.
Q: What is the maximum voltage limit for D-fend?
Q: Will D-fend protect my speakers if my amp goes DC?
Q: Will D-fend function properly with my DSP amplifiers?
Yes. D-fend is not designed to take the place of DSP in a signal monitoring sense for impedance, motor temperature, etc…However, D-fend does looks for excessive voltage conditions and is much better than DSP speaker protection in that regard.
Q: Where does the excess power go?
There is no excess power to get rid of. While this sounds strange, it is true. D-fend dynamically raises the impedance of the load that the amplifier sees, which in turn does not “allow” the amplifier to send the power. This also means the amplifier does not have to work as hard or pull as much current from the wall. This is the method that allows D-fend to avoid the heat issues that plague common speaker protection units. The excess power is simply not present as in typical protection units.
Q: Will D-fend work with tube amplifiers?
No. D-fend will NOT work with any tube amplifier. The impedance matching transformer on a tube amp is designed to have a nominal load of termination, usually 4, 6, or 8 Ohm. The transformer on a tube amp is an inductive device and that doesn’t like to go “open” on the secondary winding.
Q: Does D-fend have a low-pass/high-pass filter?
Q: Is D-fend frequency selective or broadband in its protection?
D-fend is programmable to protect across different frequency bands, but when it recognizes the need to protect, it does protect in a broadband sense. It protects across the whole system when it needs to protect at any programmed frequency.