The below table provides power consumption and thermal output for each of our loop drivers. Note that there are several variables that affect these two figures, including the output current, load resistance and audio signal. 

Full power at the highest shown load resistance (DC resistance of the connected loop circuit) is the worst-case peak scenario, but this is never a realistic representation of long-term conditions. 

1/3 peak output (pink noise) is a good approximation for long term music or 1/6 output can be used if the system is only to be reproducing speech. 

The expected resistance of your system can be obtained from your design documentation or measured if installed on site. 

wdt_ID Driver Model Number of channels Current (ARMS) Load Resistance (Ohms) Idle - AC In Sleep (W) Idle - AC In (W) Idle - BTU 1/6 peak output current - AC In (W) 1/6 peak output current - BTU 1/3 peak output current - AC In (W) 1/3 peak output current - BTU Full power - AC In (W) Full power - BTU
1 C14-2 2 14.00 0.44 9.1 23 79 41 107 92 182 389 739
2 C14-2 2 14.00 1.00 9.1 23 79 50 95 129 143 650 880
3 C14-2 2 14.00 1.20 9.1 23 79 57 107 159 187 660 647
4 C14-2 2 10.00 2.00 9.1 23 79 69 159 205 396 656 874
5 D14-2 2 14.00 0.44 9.1 22 76 41 107 90 176 317 493
Driver Model

Idle: Current delivery at zero - Quiescent Operation
1/6 peak Output Current (~1/16 Power): Current delivery speech.
1/3 peak Output Current (~1/4 Power): Full current delivery pink noise
Full Power: Full current delivery 1 kHz sine wave (Does not represent continuous real world operation)

BTU - British Thermal Unit(s)

For traditional Class AB / Class G amplifiers, the value of the load resistance has a significant bearing on how much power is dissipated outside the unit, and hence what is left for the amplifier to deal with. Therefore, it is better for the load resistance to be at the higher end of the unit range if the voltage headroom of the system will allow it. In this case as lower 'Load Resistance' radically increases the dissipation in the unit, the cooling systems for the equipment may have to deal with more than the ideal situation. (try changing 'Load Resistance' for a unit and see)

For Class D C&D-series amplifiers, the external dissipation into the load resistance has a significant bearing on how much power is required by the unit. This ultimately affects when the unit will reach a power limit, so in order to achieve large systems the resistance should be kept as low as possible. Voltage capability is still required to deliver the high frequencies into an inductive load, but may not be the limiting factor with larger systems.

Ampetronic recommend that systems be designed to cope with continuous pink noise, as in most cases (due to the lower crest factor program material) reality will be less.

Loopworks Design will calculate the current, voltage and power requirements of your system and recommend a suitable loop driver. Selecting the correct ‘system quality’ on the Design Inputs > Project tab will ensure the correct voltage headroom is allowed for the given audio source content. 

Selecting a larger gauge cable for the design will allow you to reduce the resistance and increase the power headroom available for a chosen loop driver.