User Manual

7
Rio Rancho, NM - USA
Digital-hybrid, Frequency Agile Handheld Transmitter
INPUT LIMITER
The 400 series transmitters employ a digitally-controlled analog audio limiter just before the analog-to-digital converter.
The limiter has a range of more than 30dB for excellent overload protection. A dual release envelope makes the limiter
acoustically transparent while maintaining low distortion. It can be thought of as two limiters in series, connected as a
fast attack and release limiter followed by a slow attack and release limiter. The limiter recovers quickly from brief
transients, so that its action is hidden from the listener, but recovers slowly from sustained high levels, to both keep
audio distortion low and preserve short term dynamic changes.
The audio level LEDs indicate limiter activity. The first red LED indicates that the limiter is active and that the transmit-
ter is fully modulated (audio level is between +0 and +10 dB). The second red LED indicates that the level is 10dB or
more into limiting. Occasional forays into the red are desirable for most applications, since the distortion introduced by
the limiter is so minimal, and full modulation is thus assured. We strongly recommend setting the gain of the transmit-
ter high enough so that the first red LED occasionally lights.
Generally speaking, some limiting is desirable in normal operation to improve the signal to noise ratio of the system.
The limiting action is not audible and does not create distortion. A highly trained ear would hear only the compression
of the peaks in the audio signal, which is desirable with most recorders and many sound reinforcement systems.
AUDIO LEVEL
This knob (located under the battery door) is operated while speaking or singing into the transmitter to adjust the audio
gain of the transmitter for the correct amount of modulation. The LEDs located next to it indicate the modulation level
as the gain is adjusted. See the Operating Instructions section for details on this very important adjustment.
VARIMIC CONTROLS
Caution - Due to the high RF levels surrounding the transmitter, the sound of the Varimic capsule may be temporarily
affected if the metal windscreen is not in place. Always make the final decision about sound balance and quality with
the windscreen in place.
The VariMic head includes adjustments for Bass, Midrange and Treble response. There is also an attenuation adjust-
ment to provide up to 15dB of additional headroom if needed.
BASS / MID / TREBLE (LO / MID / HI)
The bass and treble controls will boost/cut by up to ap-
proximately 8dB while the Mid control will boost/cut up to
about 6dB. These controls operate as standard tone
controls. Counter-clockwise will reduce the response in that
band and clockwise will provide a true boost. These
controls can be accessed by removing the windscreen. To
remove the windscreen, grasp the body of the transmitter in
one hand and the windscreen in the other hand. Carefully
unscrew the wind-screen counter-clockwise until it comes
off then carefully slide the windscreen past the mic ele-
ment.
• Set flat, the mic capsule is very wide range and sounds a
lot like a large competitor’s top line condenser mic.
• Bass cut gives a dry but highly intelligible sound. Crisp.
• Bass boost “fattens” the sound but is very listenable.
Does not get midbass boomy.
Bass (LO) Mid (MID) Treble (HI)