L-ACOUSTICS LA15a 115V Manual V1.0 27/01/2003
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5.7 GAIN AND SENSITIVITY
As standard, the LA15a is delivered with 32 dB gain. For most professional applications, mixing consoles
operate at a nominal level of +4 to +6 dBu, therefore the 32 dB position provides optimal gain
structure with plenty of fader movement. In addition, all L-ACOUSTICS LLC analog controllers and
OEM factory presets for approved digital processors are optimized for use with 32 dB gain amplifiers.
Sensitivity is defined as how many volts (rms) or dBu (referred to 0.775Vrms) are required at the
amplifier input to obtain full output power. Since the output power delivered varies with the load
impedance, 4 ohms is generally taken as the reference. For the LA15a, peak output power into 4
ohms is 600 W (MLS switch = 0 dB) and standard gain is 32 dB. This corresponds to an input
sensitivity of 1.22 Vrms or 4.4 dBu.
For the LA15a, the input sensitivity will depend on the specific MLS switch setting. Input sensitivity is
summarized below in Table 5.
Table 5: LA15a Output Power and Input Sensitivity versus MLS Switch Setting (32 dB gain)
LA15a
LOAD CONFIGURATION
-3 dB
0 dB
16 ohms Quad (2 channel)
95 W
200 W
(2.0 dBu)
(5.3 dBu)
8 ohms Quad (2 channel)
200 W
370 W
(2.3 dBu)
(4.9 dBu)
4 ohms Quad (2 channel)
380 W
600 W
(2.0 dBu)
(4.4 dBu)
2 ohms Quad (2 channel)
500 W
(1.2 dBu)
16 ohms Stereo (2 channels bridged)
380 W
740 W
(2.0 dBu)
(4.9 dBu)
8 ohms Stereo (2 channels bridged)
760 W
1200 W
(2.0 dBu)
(4.0 dBu)
4 ohms Stereo (2 channels bridged)
1000 W
(1.2 dBu)
Power in watts (EIA 1 kHz, 1% THD)
Sensitivity in dBu
