L-Acoustics LA4 User Manual

Also see for LA4: Owner's manual User manual User manual

L-Acoustics LA4 User Manual Manual pdf 22 page image

LA4LA4LA4LA4 Amplified ControllerAmplified ControllerAmplified ControllerAmplified ControllerUSER MANUALUSER MANUALUSER MANUALUSER MANUALVERSION 1.3.0.32ALA4_UM_EN_1.3.0.32a w w w . l - a c o u s t i c s . c o m 202020206.5.3 L-NET WiringThe LA4 can be connected to a network of several controllers driven by the PC-based LA NETWORK MANAGERsoftware. The connection is done using the I/O Ethernet sockets located on the LA4 rear panel using standard CAT5eU/FTP cables (or higher category) and RJ45 connectors (see Figure 11).Figure 11: L-NET RJ45 connector sockets for networking and remote controlNote: The network is rated at 100 Mbps. The CAT5e U/FTP reference stands for a category 5 unshielded cable withfoiled twisted pairs.6.6 Power consumptionThe LA4 power requirements summarized in Table 3 (4 channels being driven at the same time) are dependent of loadimpedance and signal level characteristics:Table 3: LA4 Maximum Output Power versus Mains Input PowerMaximum output power Mains input power and current drawLoad Number ofchannels Power 1/3 Output Power(-5 dB)1/8 Output Power(-9 dB) IDLE4 Ω 4 x 1000 W 22 A / 3250 W 12 A / 1600 W8 Ω 4 x 800 W 17 A / 2550 W 9 A / 1350 W 0.3 A / 70 WValues given for 230 V mains input. Multiply current values by 2 for 120 V. Multiply current values by approx. 2.3 for 100 V.If voltages outside a plus or minus 10 % range the maximum power is no longer guaranteed.Note: A third of the maximum output power corresponds to the worst case scenario of a program source using highlycompressed music or pink noise with amplifier driven to clip level.An eighth of the maximum output power corresponds to a loud music program with a small dynamic range and 9 dB ofheadroom (IEC standard power rating).6.7 Heat power calculationFor example, let’s connect a 4 Ω load to each output channel of the controller: each output channel can now deliver upto 1000 W output power. Consider a standard use at 1/8 of full power (9 dB headroom). The power delivered perchannel is then 1000 / 8 = 125 W, leading to a total power of 4 x 125 = 500 W for the controller. According to Table 3the controller’s power consumption is 1600 W, the heat power produced is then 1600 - 500 = 1100 watts(difference between power consumption and output power).