Electro-Voice CH230 User Manual

Page 2

CH230/CH230W Condenser Cardioid Hanging Microphone

up with “INPUT-OUTPUT” aligned as

shown in Figure 3. Start the assembly by

inserting the two 1

-in. screws into the up-

per left-hand and lower right-hand holes,

drop on the internal toothed lockwashers,

thread on the spacer and tighten against the

plate with a wrench. Repeat the procedure

for the two

-in. screws. Place the fiber

washer on each spacer.

Position the printed circuit board with

the larger terminal block and the transformer

over the printed “OUTPUT” label. Align the

screw holes in the upper right and lower left

corners of the printed circuit board with the

two 1

-in. screws and push down until the

board rests against the four fiber washers.

Take the remaining two

-in. screws and

two fiber washers and fasten the board to the

plate.

Determine the length of cable required

before attaching the microphone cable to the

printed circuit board. If the cable must be

trimmed, measure the length and add three

inches. Trim the cable by removing about 1

in. of the outside jacket, then separate the

shield from the red and white wires.

Strip

in. of insulation from the red and

white wires. Push the bare wire ends of mi-

crophone cable through the center hole in

the plate and the circuit board, then insert

the wires into the “INPUT” terminal block.

Follow the label instructions printed on the

plate. With the small-blade screwdriver,

tighten the screws in the terminal block.

Use the strain relief to fasten the micro-

phone cable to the plate by capturing the

cable about

in. from the front of the plate,

then orient the flats of the strain relief with

the flats of the center hole and squeeze and

push the strain relief into the center hole. The

strain relief will lock into place.

To attach the mixer cable to the circuit

board, trim

in. of insulation from the cable

wires and insert the wires into the “OUT-

PUT” terminal block. Follow the label in-

structions and insert the cable shield into

“SHLD GND,” and the remaining wires into

terminals 2 and 3. Warning: the CH230 and

CH230W have terminal 2 positive with a

positive pressure on the diaphragm, so be

aware of possible phasing problems if the

wires for terminals 2 and 3 are reversed.

Tighten the terminal block screws with a

small-blade screwdriver.

Set the roll-off switch to the position

desired. The rolloff filter is a two-pole, 12-

dB-per-octave high pass with a corner fre-

quency of 75 Hz.

Position the shield box with the slotted

end over the mixer cable and the screw holes

over the two 1

-in. screws. Push down the

shield box over the circuit board until the

shield is sitting on the plate. Inspect the mixer

cable connection for any shorts of terminals

2 or 3 to the shield box. With the wrench,

fasten the shield box to the plate with the

two split-ring washers and the two hex nuts.

Gently push the assembly into the

wallbox and fasten the assembly in place

with the two remaining

-in. #8-32 screws.

10. To orient the microphone in the proper

direction, loosen the holding nut on the back

of the microphone and slightly twist the mi-

crophone on the wire holder (clockwise ro-

tation moves the microphone to the left;

counterclockwise rotation moves the micro-

phone to the right). Tighten the holding nut.

Note: for fixed installations, allow the mi-

crophone cable to hang for at least 24 hours

so the cable can completely relax and estab-

lish a set. Bend the hanger wire to position

the microphone in the vertical plane.

Application Notes

When hanging one or more microphones to

provide coverage for a choir, instrumental,

or theater group, the best microphone posi-

tion for optimum sound quality and feedback

control depends on many factors—sound

system characteristics, construction of the

auditorium or theater, and the size and na-

ture of the performing group. Two general

rules to observe for the best sound coverage

are (1) microphone position and (2) the “3-

to-1 rule.”

The first rule is to suspend the microphone

approximately two to three feet in front of

the first row of performers and two to three

feet higher than the heads of the last row of

performers. The microphones are usually

aimed to point at the last row of performers

(Figure 5).

The second rule, the “3-to-1 rule,” should be

applied when more than one microphone is

required, and their outputs are combined (as

with a mixer). Following the 3-to-1 rule

avoids the deep voids and dips in frequency

response that occur when two or more mi-

crophones “see” the same signal from

slightly different distances. The 3-to-1 rule

is as follows: when multiple microphones are

used, place them at least three times as far

apart as any one of them is from the nearest

sound source. Figure 6 shows a proper ap-

plication of the 3-to-1 rule.

The CH230 and CH230W may also be used

to provide coverage for live theater applica-

tions (Figure 7). Most of the action occurs

at center stage, so the microphone should be

positioned above and pointed to the center

of the stage.

Architects' and Engineering

Specifications

The microphone shall be a back-electret con-

denser type with a frequency response of 30

Hz to 20 kHz. The microphone shall have a

cardioid polar pattern with a rear response

which is typically 20 dB below the front re-

sponse at 1.0 kHz. The microphone shall

have an output power level of –21.7 dB,

where 0 dB = 1 milliwatt per pascal, and

output shall not be appreciably affected by

the following temperature and humidity ex-

tremes: –29° to 74° C (–20° to 165° F) when

relative humidity is 0-50%; –29° to 57° C (–

20° to 135° F) when relative humidity is 0-

95%. The microphone shall have a nominal,

balanced output impedance of 150 ohms

when connected to its electronics module.

The microphone shall have a low-gloss black

finish (CH230) or a low-gloss white finish

(CH230W). The cable color shall match the

transducer. A switchable, two-pole high-pass

filter (f

= 75 Hz) shall be provided.

The transducer shall have a wire hanger for

directing the microphone. Dimensions: the

transducer shall be 10.5 mm (0.42 in.) wide

and 41.9 mm (1.65 in.) long; the cable shall

be 9.1 m (30 ft) long and 2.6 mm (0.106 in.)

in diameter. The electronics module shall fit

into either a switch box or four-inch electri-

cal box, with a rectangular switch-box plate

and circular plaster-ring cover provided.

This manual is related to the following products:

CH230W