Hall Research VSA-51-R - Manual (Page 8)

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VSA-51
13. Microphone input via Phoenix connector is designed as a differential input to help eliminate noise .
14. Speaker terminals for use with 8 or 16 Ohm speakers.
15. Receiver serial. Connects to the primary display.
16. Video Output to display via HDMI, composite video or VGA/YPbPr.
2.1.1 Mounting the VSA-51-R
The VSA-51-R ships with 2 “L” brackets attached to its sides (see photo below). This bracket is reversible and the flange
can wrap around under the product, or stick-out.
When you install the VSA-51-R in the VSA-MNT ceiling projector drop mount cage (see section 2.7), the brackets point
inward and you use the supplied #6 screws and washers to attach the receiver to the cage.
NOTE
The Mic input expects a line level signal, so you may need external preamp for low level dynamic
microphones. There is no phantom power provided at the mic input. In most K-12 installations wireless
(RF or IR based) mics are used that have line-level output. We have found that most condenser and some
dynamic mics may work without external preamps if you turn up the mic volume on the system.
Use the following diagram for connection of external preamp (such as wireless mic receiver) to the
system. Ground referenced means that the external preamp has a connection to ground (the AC cord has a
ground prong), in that case if the preamp does not provide a balanced (differential) output, you should
not tie the return of your source to the ground of the VSA-51 lest you create a ground loop. But if you are
sure that your external preamp is floating (its AC cord has no ground prong), then it may be advisable to
connect the negative input signal to ground at the VSA-51 receiver.
Mic Wiring Diagram
NOTE
The Audio Amp is designed to drive loads equal to or greater than 8 Ω. Using lower loads may cause over-
current shutdown of the Audio amp, which would require an All-Mute procedure to reset the amp. It is
recommended that when using a single speaker for each side to use 8 or 16 Ω speakers. The amp can drive
around 42 watts total when using 8 Ω speakers, which may be loud for a small room. Using 16 Ω speakers
will cut the power delivered by half.
To drive 2 speakers from each side(total of 4 speakers in the room), connect two 16 Ω speakers in parallel
or two 4Ω or 8 Ω speakers in series as shown below. Never connect two 8 Ω speakers in parallel!