Fostex 350 - P.A. APPLICATIONS

SECTION 8 P.A. APPLICATIONS
Modern PA applications require more than a simple mixer
feeding one main amplifier and speaker system. This applies
both to musical performances and theatrical applications.
The 350 mixer has the versatility to provide these extra-facili¬
ties. Stereo is an obvious requirement, though the effect must
be used with care. A recording type mix of signals, with half
the instruments coming out of the right channel only, is not
likely to please the part of the audience seated in front of the
stage left speaker!
You can use the Aux buss as described in section 4 for echo
purposes, but again a word of caution: Auditorium acoustics
usually provide an adequate degree of natural reverberation
for musicial instruments, therefore the special repeat echo
effect should be reserved for use with vocal signals. It may
be coupled directly to the channel “direct out” jack (20) or
used in the accessory send/receive path (19).
The auxiliary buss can alternatively be used to provide a
monitor mix for musicians on stage. Being stereo, and com¬
pletely independent of actual levels in the main mix (by selec¬
ting “pre” on the aux buss selector switch (5), by using the
pan-pot as a “differential” routing control you can in fact pro¬
vide two separate monitor mixes, giving the vocalist more of
the rythm, and the instrumentalists more of the vocals.
A further technique, normally associated with much more
expensive consoles, is to use the four buss system as a pair
of stereo busses A-B and C-D to separate control of the vocal
and instrumental parts of the performance, and so have a
more refined control of the overall mix. To employ this techni¬
que, connect the main stereo PA feed to the monitor output
(25). Depress all four buttons A, B, C, and D on the “monitor
select” (13). This will make A and C appear on the left
monitor output and B and D appear on the right.
You can now freely select the individual channels to either
output buss A-B for vocal or C-D for instruments using 4
channel buss selector and pan pot (3) and (4).
In operation you have complete control over the individual
levels of the vocal and instrumental “sub-groups” as they
Figure 8-1, Disco/PA hook-up
are commonly known, enabling you to keep close control
over the balance using only two faders.
This technique is also extremely useful in drama or con¬
ference sound reinforcement whereby inputs may be allocat¬
ed to the two output groups depending on the actual stage
performance area (and hence microphone location) being
covered.
If you are using the mixer locally, i.e., on stage, with micro¬
phone cables not exceeding 8 to 10 feet, connect
microphones directly. However, if you intend to use a
“snake” or “multi” type of connection to the stage, operating
over a considerable distance, we recommend that you use the
Fostex Model 1030 Mic input transformers to be located
at the mixer end.
You may want to record the performance on a multitrack
machine. There are several alternatives.
(i) Connect the direct outputs of selected channels directly to
the inputs of the tape recorder and set levels accordingly.
(ii) If you are using only four tracks you can record the main
stereo mix (use a Y split lead) plus two selected “direct outs”
from channels such as vocal or lead instrument, which can
be finally balanced during mixdown.
(in) Use the Aux buss as a stereo mix for the recorder, and
selected “direct outs” for other tracks.
(iv) Or, use Aux buss as your feed for the main PA system,
then use the 4 channel buss as your four channel recording
mix. As suggested in the previous section on AV/Disco, you
can use the tape return channels as selectable alternative in¬
put for the Model 350. This will enable you to easily switch the
mixer around for mixing in effects from disc or tape, or pro¬
vide disco or interval music facilities.
The conveniently situated overload indicators simplify level
setting. You will learn after a short while the “nominal” or
“average” setting for the input trim pots. If any of these flash
during the performance, reduce the appropriate trim control
setting (2) accordingly. A typical hook up for PA and disco
(Fig. 8-1).
PHONO 2 PHONO 1
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