YORKVILLE Power MAX Manuel De L'utilisateur page 10


L & R (Main) MASTER SEND Faders and CLIP LEDs
The left & right main summing bus receives signals directly from the channel faders, as well as the
three L&R RETURN LEVELS controls. CLIP LEDs fire a few dB lower from actual clipping so some
activity is allowable. Signal routing goes from the master faders (to STEREO EQ)... and to the SPEAKER
PROCESSOR. Then, to both the L&R LINE LEVEL OUTPUTS and the normally closed switching lugs on
the AMP A&B INPUT jacks – thereafter to amps A&B. (At the same time, the post-master signal goes
directly to the RECORD outputs, bypassing the EQ, processor, etc.)
The CLIP LEDs are unlikely to fire as this stage of the mixer has a large amount of headroom.
However, if one, or both LEDs become very active (small amounts of activity are OK), check the RETURN
LEVELS CLIP LEDs and reduce the settings of any L&R RETURN master/s in channels showing clipping.
The L&R masters regulate the level of the main stereo mix available at the RECORD outputs (no
main EQ). and the L&R LINE LEVEL OUTPUTS. They also regulate the amplifier A&B power output lev-
els (unless another mixer has been patched into the AMP A&B INPUTS in which case its masters will
determine power output).
Speaker Processor Curve and ENABLE Buttons
The POWERMAX features a choice of two low-frequency boost curves centred at 50Hz and 80Hz and
selectable via the CURVE button. The 50Hz curve has a high Q factor for subwoofers while the 80Hz curve
is slightly broader and better suited for full range cabinets. An ENABLE, ON-OFF button is also provided.
It is advisable to use this feature judiciously. For example you would probably not want to boost the main
L/R EQ's low frequencies while it is enabled. On the other hand, it can add valuable depth to the speaker
system. Experiment with it during a sound check. In case of low-frequency feedback, simply put the ENABLE
button to the OFF position.
L/R Main EQ
This is a stereo 9-band EQ on the output of the
main bus. Range is +/-12dB with centers at one-
octave intervals from 63Hz to 16kHz.
The main EQ would most often be set dur-
ing a sound check and used to carefully adjust
main speaker response (no radical boosts). It is
also useful for curbing feedback tendancies, but
remember that monitors most often cause your
feedback problems. Naturally, monitor feedback
comes out the main PA too which, when you are
out front at the mixer station, leads to the illusion
that the main system needs EQing. See under
MON1 and MON2 EQ's for more about this.
When setting the main EQ, do not automati-
cally go to a smiling curve as with a home stereo
– which will cost your system both headroom and
gain before feedback. Initially, keep the EQ curve
as close to flat (all sliders at center) as possible,
then make necessary adjustments as required dur-
ing the sound check to cut feedback frequencies.
MON1 & MON2 EQs
These are 9-band mono EQ's with +/-12dB on the
same centers as the L/R MAIN EQ. They are inserted
between the monitor buses and the # 3 & 4 power
amps, also the MON1 & 2 LINE LEVEL OUTPUTS.
These EQ's should be set flat (all sliders at
center) then adjusted for minimal monitor feed-
back during a sound check. If feedback does set
in during the job, you will be tempted to blame
the mains because that's what you hear from the
mixing station out front. Don't be misled. As a rule
it's one or more of the monitors, but of course the
noise comes out the mains too. Use your channel
MUTE buttons to mute each channel briefly and
see if the noise stops. You may also use the CLIP
LEDs to hunt for feedback channels. If the chan-
nel GAINs are set high enough per instructions,
feedback channels will have increased CLIP light