Shure FP410 - Manual

FP410 PORTABLE AUTOMATIC MIXER
The Shure Model FP410 is an automatic microphone mixer
designed for use in a wide variety of multi-microphone speech
pickup applications. Shure IntelliMix delivers flawless auto-
matic mixing by combining three unique functions:

Noise--Adaptive Threshold,

MaxBus, and

Last Mic Lock--On.
Noise--Adaptive Threshold distinguishes between constant
background noise (such as air conditioning) and rapidly
changing sound (such as speech).This function continuously
adjusts the activation threshold so that only speech levels
louder than the background sound will activate an FP410
channel.
MaxBus eliminates the poor audio quality that results when
a talker is picked up by more than one microphone. It does this
by controlling the number of microphones that may activate for
a single sound source. With MaxBus, one talker will activate
only one FP410 channel, even if multiple microphones are
“hearing” that talker.
Last Mic Lock--On maintains a seamless audio mix by keep-
ing the most recently activated microphone open until a newly
activated microphone takes its place. Without Last Mic Lock--
On, a long pause in conversation may allow all microphones to
turn off, and it may sound as if the audio signal has been lost.
Last Mic Lock--On ensures that background ambience will al-
ways be present.
Multiple miking situations—with a number of talkers partici-
pating—have always presented problems for the audio techni-
cian. If too few mics are used, the coverage of each talker may
vary, with one talker (nearest the mic) being louder and clearer
than the next. Talkers farthest from the mics will sound
“echoey” and reverberant, as very little of the direct sound from
their mouths reaches the microphones. If too many mics are
used, there’s more background noise and reverberation pick-
up, as well as less gain before feedback if a sound reinforce-
ment (PA) system is used.
It’s somewhat like having multiple video cameras all fo-
cused on the same subject. If these camera signal are com-
bined, the result is a blurred image. When multiple micro-
phones are open for a single talker, the result is a blurred audio
signal. But it’s often not practical for someone to turn mics on
when they are needed and off when they are not. The answer
is the FP410 automatic microphone mixer.
The FP410 automatically attenuates (turns down) any mi-
crophone not being used, greatly reducing the excess rever-
beration and feedback problems associated with the use of
conventional multiple microphone and mixer techniques.
When a new talker starts to speak, the FP410 immediately se-
lects and silently activates the most appropriate microphone.
Shure IntelliMix electronic signal processing enables the
FP410 to provide clear, natural voice pickup. The FP410 sig-
nificantly reduces the problems of “boomy” or “muddy” sound,
insufficient sound level (because of feedback or “howling”),
and operator errors. In fact, operator errors are virtually elimi-
nated because the FP410 needs no operator or technician for
continual adjustment—once set up, it is completely self--suffi-
cient.
The FP410 has numerous applications in video production
and audio recording, broadcasting, and sound reinforcement.
In any speech pickup application where multiple microphones
are required, the FP410 dramatically improves audio quality.
Switching from manual to automatic operation allows an indi-
vidual talker’s voice to rise above the background noise and
reverberation to become clearer and more intelligible.
Each FP410 handles up to four microphones or line--level
signals. Any high quality, low--impedance, balanced micro-
phone using a dynamic or condenser* transducer (including
wireless and shotgun types) can be used. Additional FP410
mixers can be interconnected using the rear--panel link jacks.
Complete manual operation is also available using a front--pa-
nel selector switch.
The FP410 is supplied with optional bumpers (feet) for use
on horizontal surfaces, a short cable for linking two FP410 mix-
ers, and a rack--mounting kit for installation in a standard 483
mm (19--inch) audio equipment rack.
The FP410 (100 to 120 Vac operation; line fuse 0.1 A) is also
supplied as the Model FP410E (230 Vac operation; line fuse
0.05 A), and its line cord contains a Schuko ac plug.
*Self--powered or operable on 14 or 48 Vdc phantom power.
Features

Reliable, quick--acting, noise--free microphone selection----
automatically adjusts to changes in background room noise

Front--panel channel gain and master controls operate as in
conventional mixers

Selectable hold time keeps microphones on during short
pauses in speech
Shure Incorporated
222 Hartrey Avenue
Evanston IL 60202-3696 U.S.A.
Model FP410 User Guide
27B8392 (TB)
E 2000, Shure Incorporated
Printed in U.S.A. U.S. Patent 4,658,425; other patents pending