Yorkville Sound AP818 ユーザーズマニュアル

Addendum

EQ Sweep Control

Although frequency

sweep controls have graced the channel-EQs of recording

mixers for many years, they are only found on the more upscale PA mixers. As a
result many PA users, even veterans, are unfamiliar with their function. The

SWEEP control determines what range of frequencies is affected by the MID

cut/boost. It moves or sweeps the MID control's peak or notch in response all

the way up to several thousand Hertz or down to below 100Hz. As a result it

can have quite a noticeable effect on the sound especially since the

MID cut or

boost will be interacting with whatever cuts or boosts you may have set with the

LOW or HIGH EQ controls.

For example, if you have set a LOW boost, a MID boost swept all the way down to the lowest

frequency setting will alter the sound of the lows and increase their volume. Be careful this

doesn't damage your woofers. And watch out for your tweeters/horns if you sweep the boost up

to the higher settings while the HI EQ is boosted.

Considering that the

SWEEP control can alter everything you are

accustomed to an

EQ doing, it would be worthwhile to spend some time

becoming acquainted with how it works. As music plays through a channel on
the mixer and speakers, adjust that channel's

MID, first for a boost then for a cut

and

SWEEP them back and forth. (If there is no MID cut or boost setting, i.e. if it

is set at the center position, the

SWEEP will have no effect at all). Now repeat

the process with that channel's

LOW and HIGH EQ controls at various settings

(but with the volume at a safe level for the speakers).

Hint: The PowerMAX SWEEP has a home base setting marked with a triangle at the 2.5kHz

mark. This approximately corresponds to the setting of the fixed mid controls on our other

mixers. Set channels not requiring SWEEP equalization at 2.5kHz and the MID cuts or boosts

will have more standard results.

Together,

MID and SWEEP controls can be used to accomplish a variety

of tasks from combating feedback to improving the way things sound

through the PA or on recording. Here are some of those tasks & settings:

Note: These are approximate settings only. Use them as a starting point and tune around them.

•

Killing feedback? Set MID at -6dB and slowly rotate SWEEP until the feedback stops. If

needed cut the

MID further.

•

Bonky sounding snare drum? -6dB @ 200Hz (roll off LOW EQ -6dB)

•

Boomy bass drum? -6dB @ 300Hz (LOW EQ @ +6dB & HIGH EQ @ +3dB)

•

Fwashy sounding cymbals? -9dB @ 300Hz (roll off LOW EQ -15dB)

•

Excessive hiss from guitar, bass or keyboard amp? +3dB @ 5kHz (HI EQ rolled off -9dB)

•

Fading vocal range (notes too low for singer)? +3dB @ 80Hz (LOW EQ rolled off -6dB)

•

Puffing on harmonica mic? -9dB @ 80Hz (LOW EQ rolled off -12dB)

•

Rack Toms? -3dB @400 Hz

•

Floor tom? -6dB @ 200Hz

Generally speaking, you will probably end up with the

MID in cut mode

for most problem solving uses of the

SWEEP control. In any case you will

learn to use this feature judiciously. The best

PA EQ setting is the one with

the

least adjustment, but when you need to solve a problem it's good to

know how to use the tools.

EQ MID SWEEP Addendum 01.06.28.99