YORKVILLE AP812 Manuel De L'utilisateur page 8

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a) Up in the L & R position, the ASSIGN button directs the Left & Right MAIN
master signals to EQ1 and EQ2 respectively. Thereafter, they go in two direc-
tions at once to the L & R (AMP 1 and AMP 2) inputs of the built-in power
amplifier and to the L & R POST EQ LINE OUTPUT jacks.
b) Down in the MAIN/MON position, the ASSIGN button also does two things.
First, it sums some of the LEFT and RIGHT MAIN signals into a single mono
signal and directs it to the input of EQ1, the output of which is then split and
goes to both the LEFT power amp channel and to the POST EQ MAIN (L)
LINE OUTPUT jack. Secondly, the button takes some of the MON MASTER's
output signal and routes it to the input of EQ2, thereafter to be split and rout-
ed to the RIGHT channel of the built-in power amplifier and to the POST EQ
MON (R) LINE OUTPUT jack.
User tip: The stereo operating mode of the AP812 would be with the EQ/AMP ASSIGN
button up in the L & R position. This would supply up to 800 watts of stereo power (400
watts/channel) plus separate L & R 9-band EQ's for the main system speakers. Power and
equalization for the monitors would come from a separate power amplifier and graphic
EQ. With the EQ/AMP ASSIGN button down in the MAIN/MON position, you now have
400 watts of mono power @ 4 ohms plus a single 9-band EQ for the main PA speakers,
also 400 watts @ 4 ohms and a single 9-band EQ for the monitors. Connect main PA
speakers to the AMP 1 SPEAKER OUTPUT's and monitors to AMP 2 SPEAKER OUTPUTS.
See under SPEAKER CONNECTIONS for suggested speaker impedances.
Pre & Post EQ Line Outputs
These are the outputs of the L & R main mixing busses. They are all at line level (do
not connect speakers directly) and unbalanced. The PRE EQ outputs are not affected
by either of the graphic equalizers. The stereo main mix is available from them at all
times, regardless of the EQ/AMP ASSIGN button setting. These would be available
for connecting a secondary mixer perhaps for a house PA, broadcast and/or recording
purposes. These outputs, although not balanced, have been designed to supply the
noise-canceling benefits of balanced outputs as long as the inputs of the unit (power
amp or mixer) you are con-
necting them to have bal-
anced inputs, and you use
TRS balanced cables.
The POST EQ output
signals are affected by the
graphic equalizers. They are
also affected by the EQ/AMP
ASSIGN button. With the
button up in the L & R MAIN
position, these jacks receive
the output of EQ1 at the L
MAIN jack and EQ2 at the R MON jack. With the EQ/AMP ASSIGN button down in
the MAIN/MON position, the L MAIN jack receives mono (left & right mixed togeth-
er) main mix signal from EQ1 and monitor signals from EQ2. The POST EQ outputs
are best for driving power amplifiers whether for main or monitor speaker systems.
EQ1 & EQ2 Graphic Equalizers
The Q factor is greater in cut-mode than in boost-mode, which is desirable when
using the EQ for feedback control. Up to 12 dB of cut or boost is available. For more
information about their internal routing, see under LEFT & RIGHT MAIN MASTERS
and EQ/AMP ASSIGN BUTTON above.
User tip: As with all graphic EQ's, minimal variations above or below center settings
are always recommended. The only exception to this rule might be in the fight against
feedback, but even there the ideal solution is to separate the offending speaker from
the offending mic or at least aim them in different directions. This way the whole sys-
tem's natural frequency response does not have to be compromised because of one mic
and one speaker. Ideally, a Real-time Frequency Analyzer and Pink Noise would be
employed before the audience arrives to help you pre-adjust the EQ (s) to cut obvious
system/room response spikes likely to cause feedback later on. Without such devices