D-fend SA300 User Manual - page 5
5
D-fend™ SA300 User Manual
C. LF PEAK – this LED indicator illuminates in the event that the user-defined low frequency peak voltage thresholds
have been matched or exceeded. A red light here signifies peak voltages in the low frequency band have triggered
attenuation. A green light here in conjunction with a red fault light signifies that significant DC energy was detected
and the device will momentarily disconnect the loudspeaker to protect against long-term DC damage.
D. FAULT / COMM – this LED indicator illuminates red if the D-fend device senses a DC voltage, over current, or over
temperature fault situation. Any of these three faults will result in momentary loss of audio. DC faults will be indicated
by a red fault light AND a green LF peak light. Over temperature or over current faults will be indicated by a red fault
LED. In the event of an over current or over temperature event, it is advisable to reduce the audio level and/or check
the speaker impedance to ensure you are operating within the specified parameters of the SA300. A green light here
signals that D-fend is ready for communication and connected by USB.
E. USB – The SA300 is equipped with a mini-USB connection for programming and communication purposes.
F. POWER – this LED indicator illuminates yellow when D-fend is being supplied with adequate power from either the
audio line or external power supply.
G. 12 VOLT DC – D-fend is equipped with DC power connection in the event that desired protection threshold settings are
below the minimum audio signal power required to activate the D-fend protection device (see Specifications section
below) or in the event that it is undesired to use the audio signal as the power source.
H. NL4 Neutrik Input and Output Connections – Please note +2 and -2 pins on both connections are unprotected pass
through. The SA300 does NOT provide protection on pins 2 of the NL4 input/output circuit path.
Specifications
Maximum Power Specifications
The D-fend SA300 has maximum peak voltage and current ratings of 300 volts and 25 amps, respectively. Therefore,
maximum power specifications are impedance dependent. Below is a table listing the maximum input power D-fend is
capable of safely managing.
D-fend Maximum Power Specifications
1,250 W @ 2Ω
2,000 W @ 4Ω
3,000 W @ 6Ω
4,000 W @ 8Ω
2,000 W @ 16Ω
Minimum Power Requirements
The D-fend SA300 requires a minimum amount of audio signal power in order for the protection circuit to function properly.
The amount of power required to activate the D-fend protection circuit is dependent upon the source of the supplied
power as well as the impedance load of the connected system(s) that are to be protected. The minimum power required
can be greatly reduced with the use of an external power supply (sold separately) which may be advantageous for some
applications. Below is a chart illustrating the minimum power requirement of the D-fend SA300 if incorporating an external
power supply, or if using only the audio signal as the power source.
Minimum Continuous Audio Signal Power Required
Impedance (Ω)
Using External Power Supply (W)
Using Only the Audio Signal (W)
2
0.500
32.0
4
0.250
16.0
6
0.167
10.7
8
0.125
8.0
16
0.063
4.0