ENGLISH
EUROLIVE VP1220/VP1220F/VP1520/VP2520/VP1800S User Manual
5
Avoid placing full-range loudspeakers in a corner or right next
to a wall. This enhances the low frequencies and can cause the
sound to get muddy. Subwoofers may be placed almost anywhere
since low frequencies are not highly directional.
Make sure that the loudspeakers are not in a place where they
could be knocked over by dancing audience members, overly
eccentric stage performers, sudden earthquakes, etc.
Some rooms, such as gymnasiums and auditoriums, create a
large amount of natural reverb, making it difficult to maintain
intelligible sound. Laying carpet or rugs on the ground and
curtains across windows or brick walls will help dampen the
reflections and improve the overall sound.
How to prevent feedback
3.2
Always place the “front of house” speakers ahead of the micro-
phones (from the audience’s perspective), and never behind. Use
professional floor monitors or an in-ear monitoring system to
allow the stage performers to hear.
How to avoid feedback when
3.3
working with record players
(DJ applications)
In applications with record players, bass feedback can occur.
Bass feedback occurs when low frequencies get back to the
pickup and are reproduced on the loudspeakers. The most
common causes for this are: speakers located too closely to
the record player, a room with a wooden floor, or presence of a
podium or a platform. In such cases, it is best to move the
loudspeakers away from the record player and remove them
from the stage, so that they are located on firm ground. Another
option is to use raised stands, which prevent the loudspeakers
from having a direct contact with the ground.
Loudspeaker protection by using a
3.4
low-cut filter
Try to prevent damage to your loudspeakers caused by extreme
oscillation of the low-frequency driver due to subsonic noise
and extremely deep frequencies. Use an equalizer to cut off
those frequencies that fall below your loudspeakers’ frequency
range, or use a low-cut/high-pass filter. Most equalizers and
sound-improvement systems offer a low-cut function, like the
BEHRINGER ULTRAGRAPH DIGITAL DEQ1024, for example.
Using a low-cut filter in your signal path is particularly recom-
mended if you use record players or CD players as your signal
source. CD players often produce extremely deep frequencies,
which can lead to extreme excursions of the low-frequency driver.
Additional Considerations
4.
Length and diameter of
4.1
loudspeaker cables
Loudspeaker cables whose diameter is too small can consider-
ably limit the power amp performance. The longer the cable,
the more pronounced the problem. As a result, musicians
often simply “turn up” the amp, which can lead to loudspeaker
damage. Therefore, don’t use cables longer than 15 m (45 ft.).
For most applications, this will not be necessary. Cable diameter
should be at least 14 - 12 gauge.
Power amp rating
4.2
Selecting the right amp can turn out to be rather difficult.
Therefore, stick to the following rule of thumb: the power rating
of your amp should be roughly twice the loudspeaker load capac-
ity. A loudspeaker rated at 200 Watts continuous performance
can easily be powered by an amp rated at 400 Watts output
power. An optimal addition to your speaker system would be the
BEHRINGER EUROPOWER EP2000 power amp, for example.
Fuses
4.3
We do not recommend the use of fuses with loudspeaker applica-
tions. Damage to loudspeakers can be the result of high peak
signals and high output power. However, fuses can only offer
protection from one of these two factors, and never from both.
Additionally, fuse resistances are sometimes nonlinear, leading
to distortion and unpredictable overdriving.
Protecting your equipment
4.4
Always try to find the optimal signal level. Avoid overdriving
•
your amp.
Keep in mind the physical limitations of your PA system.
•
Use a limiter to restrict the output signal level. Place the
•
limiter between the mixing console and the power amp. For
this purpose, our proven AUTOCOM PRO-XL MDX1600,
COMPOSER PRO-XL MDX2600 and MULTICOM PRO-XL
MDX4600 compressors offer an outstanding solution. All
models can be used as a limiter: the audio signal doesn’t
overdrive any more, and unpleasant “peaks” are effectively
avoided.
Our ULTRADRIVE PRO DCX2496 and SUPER-X CX3400/
◊
CX2310 crossovers are particularly well-suited for
protecting your equipment: for each output, they have inde-
pendent limiters.
