Operation Manual

5. Operation and performance

C SERIES Operation Manual rev 2.0.0

5.4.5. Ampliﬁer sensitivity

Sensitivity is dened as how many volts (rms) or dBu (referred to 0.775 Vrms) are required to achieve full

(maximum) output power. As the output power varies with the load impedance, 4 ohms is usually the common

reference.

Since C Series ampliers are capable of providing multiple maximum output power levels through use of the

VPL feature, many sensitivity calculations may be required for a single amplier. We recommend use of the

DeviceControl software to simplify this process. DeviceControl’s Device View page, used in combination with the

DIP-switch settings display, will automatically produce a sensitivity calculation from the given data (VPL, Gain

and load).

5.4.6. Output Voltage Peak Limiter (VPL)

The Voltage Peak Limiter (VPL) is a unique feature in C Series ampliers. It is used to select the maximum power

available on each output channel. Four levels can be set using the DIP-switches on the amplier’s rear panel.

V peak Vrms

100 70.7

63 44.5

45 31.8

32 22.6

The values for VPL are displayed as maximum Voltage Peak. To translate Voltage Peak into Vrms, you must divide

the Voltage Peak values by 1.41 (see table 5.4.6).

The VPL allows you to set the correct maximum output peak power for optimum performance with the connected

speakers. The correct setting depends on the system type (low or high impedance) and the specic load

connected to the channel. Since each channel can be congured to deliver either very high voltage peak power

OR high current draw at low impedances, it is important to set the VPL correctly.

To congure an individual output channel for a constant voltage system, you simply adjust the DIP-switches to

the desired voltage. However, when using an output for a low-impedance system ( 4, 8 or 16 ohms), then you

may need to adjust the VPL to a lower setting to avoid either delivering excessively high continuous power to the

speaker or overheating of the output channel through high current draw. For example, with a very “hot” continuous

output signal, the temperature could rise to a critical level and activate Temp warning or even Temp Mute. Lowering

the VPL setting usually will solve this situation.

If the Current Peak Limiter is active or indicates low impedance, lowering the VPL setting can rectify this situation

as well.

Figure 5.4.6: VPL values in both V peak and Vrms