Shure Sonodyne II 540SH Datasheet

222 HARTREY AVE., EVANSTON, IL. 60204 U.S.A.

Q

MICROPHONES AND

ELECTRONIC

COMPONENTS

MODEL 540SH

AREA CODE 3121866-2200 . CABLE: SHUREMICRO

SONODYNE@ II

TWX:

910- 231-0048 TELEX: 72-4381

I

OMNIDIRECTIONAL DYNAMIC MICROPHONE

GENERAL

The Model 540SH SONODYNEQ

II

is a dual­impedance omnidirectional dynamic microphone with
response tailoring capability at both the low and
midrange-to-high frequencies.

As supplied with its extended low and high frequency
response, the microphone is excellent for both music
and voice in public address and recording. In addition,
its tailored response provides highly intelligible speech
reproduction in communications and paging applica­tions.

The

540SH microphone is designed for stand mount-

ing and has an On-Off switch on the integral

positive­action swivel mount. Solderless impedance change, a
strong detachable cable with

a

professional three-pin
audio connector, rugged construction, all make the
SONODYNE

II

a very versatile microphone.

Microphone Features:

Excellent reproduction of voice and music
Omnidirectional pickup pattern, picks up sound all

around
Response tailoring at both low and midrange-to-

high frequencies

m

Solderless impedance change
Built-in On-Off switch, an integral part of the at-

tached, positive-action swivel assembly
Rugged professional three-pin audio connector on

the microphone
Strong, detachable cable especially selected for ef-

fective shielding from hum pickup
Can be used indoors or outdoors, dependable under

all operating conditions

SPECIFICATIONS

TY pe

Dynamic

Polar Pattern

Omnidirectional

lmpedance

Dual. Microphone rating impedance is 150 ohms (230
ohms actual) for connection to microphone inputs
rated at 19 to 300 ohms and "High" for connection to
high-impedance microphone inputs. Wired for low
impedance as supplied. To change impedance, see
sections on lmpedance Selection and Connections.

Output Level

(at 1,000 Hz)

IMPEDANCE

Low High

Open Circuit Voltage*. . . . . . . -79.0 dB

-55.0 dB

(.I 12 mV) (1.78 mV)

Power Level*

*

. . . . . . . . . . . .

-

58.5 dB

*O dB

=

1

volt per microbar

**0 dB = 1 milliwatt per 10 microbars

Phasing

Positive pressure on diaphragm produces positive
voltage on pin

2

when connected for low impedance,

on pin

1

when connected for high impedance. (See

Figure

4.)

Frequency Response

50 to 13,000

Hz.

Provision for low-frequency rolloff

Switch

and midrange emphasis (see Figure 1)

Built-in On-Off switch, integral part of swivel mount

TYPICAL FREQUENCY RESPONSE

FIGURE

1

Cable

4.6m (15 ft) two-conductor shielded, with profes­sional three-pin female audio connector*

'Designed to mate with Cannon XL series, Switchcraft A3

(Q.G.)

Series, or

equivalent connector

Case

Black and silver finish metal and black ARMO-DURQ

Dimensions

See Figure 2

Copyright

1980,

Shure Brothers Inc.

27A1555 (TC)

Printed in U.S.A.

23.9

mm

g-27THREAD"f42,1

mm

4

05/16

IN)

(1-23/32 IN.)

OVERALL

DIMENSIONS

FIGURE 2

Net Weight (less cable)

425 grams

(1 5 oz)

Packaged Weight

1.07 kg (2 I b,

6 oz)

RESPONSE SELECTION

The Model

540SH SONODYNE@ II frequency response

can be tailored for low-frequency

rolloff or midrange

emphasis as shown in Figure

1. Both the rolloff and em­phasis are desirable if the microphone is used for voice
communication or in a paging system, since the tailored

response enhances intelligibility of the speaking voice.

The microphone is supplied with the extended low and

midrange response shown in the solid line curve of
Figure

1. To modify the microphone response proceed

as follows.

A. Provide midrange emphasis:

1.

Hold the microphone in a vertical position; un­screw (turn counterclockwise) and remove the
microphone grille-cap assembly (see Figure 3).

2.

Remove the perforated aluminum resonator plate
(used for extended response); substitute the
18-hole resonator plate (supplied), and add one
spacer (for a total of two).

3. Reassemble the grille-cap to the microphone,
making certain that the cartridge is properly
seated. Tighten securely.

B. Provide low-frequency

rolloff:

1. Locate the threaded hole at the back of the
microphone (see Figure 3).

2. Use a small screwdriver to remove the headless
No. 4-40 set screw in the threaded hole. Opening

the acoustic port produces the low-frequency

rolloff shown in Figure 1.

rSTEEL SPACERS

ACOUSTIC

LLE-GAP

i

1)

REsoNmod GARTwDGEJ fMcRoPHoNE cnse REAR VIEW

PLATE

OF MICROPHONE

RESPONSE

SELECTION

FIGURE

3

IMPEDANCE SELECTION

The Model

540SH is supplied connected for low­impedance operation. The low-impedance connection is
recommended where long cable lengths are required or

under conditions of severe hum disturbance. The per­missible cable length is practically unlimited since

neither response nor level is appreciably affected by
long cables. Shure Model A95 Series Line Matching

Transformers are available for use when a

low-

impedance microphone line is desirable but the

associated amplifier has a high-impedance input. These
transformers provide a proper impedance match be­tween a 19 to 300 ohm microphone line and a

high­impedance input and are available with various input
and output connectors.

To change the Model

540SH to high impedance, pro-

ceed as follows.

1. Remove the two screws that hold the switch.

2. Gently pull the switch and its plastic housing for­ward out of the swivel taking care not to break any

leads.

3. With

a

long-nose pliers, lift upward and discon­nect the 2-terminal black plastic impedance selec­tion socket from the back of pin 3 of the audio con­nector. Take care not to break leads while perfor­ming this operation.

4. With the long-nose pliers, replace the impedance
selection socket with pin 3 of the audio connector

inserted in socket terminal "H". Press the plastic

socket firmly in place.

5. Reassemble the switch housing, switch, and
switchplate in the swivel taking care not to pinch
any leads.

6.

Fasten securely with the two previously removed
screws.

CONNECTIONS

When using the microphone in low-impedance, the
BLACK and WHITE cable leads are the "hot" conductors
for balanced-line connections; the shield is connected
to the chassis or amplifier ground.

When using the microphone in high impedance, the
WHITE cable lead is the "hot" conductor; the shield is
connected to the chassis or amplifier ground. The

BLACK cable lead should be insulated.

PHASING

To test two microphones

andlor their cables for prop­er phasing, connect them to an amplifier and talk or
sing into them while holding them three or four inches
apart. The sound from the speakers should be the same
when talking into either microphone or directly between
them if they are in phase with each other. If the sound
drops drastically, or if a dead spot is found when talking
between the two microphones, either the microphones
or their cables (low impedance only) are out of phase.
All cables and microphones should be tested in this
manner to insure that they are in phase with each other.

To change the phase of a low-impedance microphone

cable, either use a Shure

A15PRS Phase Reverser or in-

terchange the wires connected to pins

2

and 3 of the

connector. To change the phase of a microphone,