- ページ 8
アンプ Elite Acoustics Engineering A25UのPDF マニュアルをオンラインで閲覧またはダウンロードできます。Elite Acoustics Engineering A25U 11 ページ。 Acoustic amplifier with 4 channels, mixer, effects, battery powered and bluetooth
ページを印刷する
Simply put, the annoying shrilling howl of growing and untamed feedback is the result of "in-
phase" frequencies getting together and being reinforced by the sound system and environ-
ment.
Phase Switch – since the purpose of the Phase Switch is to reverse the polarity, the first line
of defense is to change the phase, which can sometimes be a cure all by itself. This has the
effect of changing the phase relationship between the amplified signal and live sound, which
can break up some "in-phase" reinforcing components. On the other hand, it's preferred if we
can leave the phase set to provide the most natural and balanced sound.
Notch Filter – Another way to prevent "in-phase" reinforcement is to simply find and "notch"
out the offending frequency. The approach is straight forward; with the Notch set to full "cut"
(counter clockwise), slowly rotate the Notch Frequency to align with and cancel the offensive
tone.
Phase and Notch – probably the most widely used approach is to start without the notch
filter engaged, and to bring up the gain and or volume to encourage feedback. Changing the
Phase will change the frequency of the feedback. Leave the Phase set to whichever setting
produces the higher pitched note.
Next, use the aforementioned Notch technique to hone in on and prevent the feedback. Keep
in mind, fighting feedback in this manner may or may not appeal to your taste in overall tone.
It's certainly fair to experiment and try it the other way around, i.e., Phase switch to stop HF
tone and Notch to cutout the LF tone. After all, Live Sound is an Art and when it's all said and
done tone is King.
ORIGINAL A2-5 SLA BATTERY & RECHARGING INFORMATION
1.
To fully charge a unit –
a. Set Battery Switch to "CONNECT"
b. Turn Power Switch OFF
c. Connect "AC" adaptor to Power Jack.
d. Blue "Charge" LED should be lit, Charge time can vary from 24 – 36 hours
depending on model.
2.
When unit is powered with "AC" adaptor, Battery Switch should be in "CONNECT"
position.
3.
Battery Switch should be on "DISCONNECT" when unit is packed for transit or unit
is in storage. Make sure battery is fully charged before UNIT is put into storage. We
recommend fully charging the battery at least once each month.
4.
SLA battery lifetime is typically 1 – 2 years depending on usage.
Battery
Level
•
3
•
2
•
1
•
Low
•
•
Charge
HOW TO DEAL WITH ACOUSTIC FEEDBACK
SLA BATTERY - FOR MAXIMUM BATTERY LIFE
Recharge after every use
Use & recharge battery at least once a month
DO NOT leave power switch in the "ON" position when it is not in
use. Doing so after a long period of time will damage the battery
Keep unit in a cool, dry place away from extreme
temperatures
Do not service, modify, or replace the battery
If the battery fails to charge, contact Elite Acoustics Designs
6