L-ACOUSTICS LA 24 MANUAL Version 2.2
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While the SMPS might sound complex it is actually very straight forward and has high
reliability. The net performance result is good bass and fast transient response. Because the
supply is regulated, the LA 24 will produce the same power output even if the AC line voltage
falls by up to 20% ! Efficiency is also assured, and in the case of the LA 24 this is especially
apparent - its power supply draws only 4 kW while producing 2 x 1400 W. For a conventional
amplifier, typically only 2 x 650 W would be produced and nearly 3 kW wasted as heat.
Traditional PSUs can also behave erratically at certain frequencies - particularly at low
frequencies under clip conditions where their output impedance rises. This produces
uncontrollable speaker cone movement and under these conditions clip states are more
audible for the case of conventional PSUs.
By comparison, the L-ACOUSTICS SMPS produces its rated power output at all frequencies
regardless of speaker demands and AC line conditions.
MLS™-switches
Thanks to the regulated SMPS, the maximum power available from the output stages can be
adjusted without increased heat dissipation or efficiency loss. This allows users to match the
output power to the loudspeaker load impedance.
The LED bargraph is also adjusted to give a correct reading relative to the selected output
power. Because the amount of power delivered into a load is dictated by its impedance (at 2
ohms you use the least voltage but require the most current), you can cheat with the MLS
switches thereby enabling powers in excess of the normal power rating.
