Shure 55AV, 55BV, 55CV User Guide

DATA SHEET

DATE:

No.

188

SUBJECT:

Models 55AV, 55BV, 55CV “Voice Unidyne” Dynamic Microphones

55V SERIES "VOICE UNIDYNE" MICROPHONES

(CARDIOID UNI-DIRECTIONAL

GENERAL:

high quality reproduction of the speaking and sing-

ing voice. The true unidirectional characteristic of the "Unidyne", obtained by the "uniphase" principle provides highly satisfactory operation under adverse acoustic conditions where a conventional

microphone would be practically useless. (See "Acoustic Considerations").

The microphone has a specially designed moving

system containing a new type moving-coil element,

operating in conjunction with a high flux magnet in the magnetic circuit providing high efficiency and smooth peak free response from 100 to 10,000 cycles. The rear response is down approximately 15 db due to the "uniphase" unidirectional acoustic network.

The case is modern in design with attractive streamlining and grille treatment. The head tilts through an angle of 90° to permit aiming at the source of sound for best pickup. A built-in cable connector is provided and a 12 ft. shielded rubberjacketed cable with microphone plug attached is included.

APPLICATIONS:

voice. They are particularly satisfactory as a soloist’s microphone, for announcing at sport events, and also for communications and paging especially when background noise is present. "Voice Unidynes" are not intended for high fidelity reproduction of music. For this purpose the 55 and 555 Series microphones are recommended. The true unidirectional characteristic of the "Unidyne" provides an easy solution to the feedback problem in reverberant

locations, facilitates orchestral placement, permits best utilization of space in small broadcast studios, and allows practically complete exclusion of unwanted noises. The swivel allows the head to be

tilted through an angle of 90°, permitting the microphone to be aimed at the source of sound.

The instrument is unusually rugged and is prac-

tically immune to the effects of moisture, tempera-

ture and mechanical vibration.

INSTALLATION:

stand. Shure floor stands are especially recommended because of the effective isolation against floor vibration which they provide. For overhead suspension, an A35B Suspension Adapter may be used.

CONNECTIONS:

impregnated transformer with special high-permeability core. The three models, their out-put im-

pedances, and cable furnished are listed below.

MODEL IMPEDANCE 55AV - 35-50 ohms

55BV - 200-250 ohms

55CV - high impedance

Low impedance models 55AV and 55BV are recommended where long cable lengths are required. The permissible line length is practically unlimited since neither the level nor the frequency response

is appreciably affected by reasonable lengths of

Models 55AV, 55BV and 55CV are unidirectional moving coil dynamic microphones designed especially for

Models 55AV, 55BV and 55CV are suitable for high quality public address and broadcasting and recording of

All microphones have the standard 5/8"-27 thread and may be mounted

on any Shure desk, banquet, or floor

Model 55AV works directly into a 3550 ohm line while models 55BV and 55CV include an internal high quality

CABLE FURNISHED

12 ft. two-conductor 12 ft. two-conductor 12 ft. single conductor

MOVING-COIL DYNAMIC)

line. As shown in the table below, the cable loss

is very small. When long lines are used, care should be taken that the cable does not parallel A.C. power lines for long distances to avoid A.C. hum induction.

CABLE LENGTH

12 ft.

25 ft.

250 ft.

500 ft.

1000 ft.

2000 ft.

*Based on 2-conductor #20 equivalent,

Low impedance models 55AV and 55BV may be fed

into a standard low impedance input amplifier (see

Fig. A-3) or into an amplifier with high impedance

input (Fig. A-2). In the latter case Shure Model

A86A Cable-Type Transformer is available for coupling

the low impedance line to the amplifier input. The double-winding primary permits coupling either a

35-50 ohm line or 200-250 ohm line to the high im-

pedance input.

High impedance model 55CV may be used with any crystal microphone amplifier or other amplifier with an input impedance of 100,000 ohms or more (see Fig. A-l). For best high frequency response, the total cable length should not exceed 25 feet; longer cable lengths may be used with some loss of high

frequency response. The additional loss at 5,000 cycles is of the order of 2.5 db for an additional 25 ft. length of cable (50 ft. total) and 6 db for additional 50 ft. length (75 ft. total).

OPERATION:

fier. Jarring or excessive moving of the instrument should be avoided while the system is in operation

in order to prevent the spring-suspended microphone

unit from touching the inside of the case and pro-

ducing undesirable noises.

No special precautions beyond ordinary care are

necessary in the operation of 55V Series Dynamic

microphones. They will operate efficiently and de-

pendably under all ordinary conditions in hot and cold climates. To retain the full strength of the highly efficient permanent magnet and to maintain

LOSS IN LEVEL*

MODEL 55A MODEL 55B

0 0

0.4 db

0.8 db

1.6 db

2.9 db

twisted and shielded.

The microphone should be placed in its operating position before turning up the volume controls of the ampli-

LOSS IN LEVEL*

0 0

db db

0.2 db

0.4 db

0.7 db

DATA SHEET

alignment of the structure, dropping or other severe mechanical shocks should be avoided.

ACOUSTIC CONSIDER-

ATIONS:

pickup angle at the front of the microphone while

the response at the sides is down 6 db from the

front response. The rear response in practical

cardioid type microphones is down of the order of

15 db from the front side response. The Unidyne

fulfills these requirements over a broad range of

frequencies. The true unidirectional characteristic

of the "Unidyne" should not be confused with the relatively slight directional effect at high frequencies only which can be produced by‘ baffle ef-

fects in the conventional pressure microphone.

The result of this unidirectional character-

istic is a complete elimination of acoustic feedback at volume levels which would cause considerable feedback with conventional semidirectional microphones. In practically all cases it is possible to

increase loudspeaker levels when a Unidyne is installed. By directing the dead side (rear) of the microphone towards the audience or other source of

interfering sound, pickup can be concentrated on the desired source. Reverberation energy pickup is decreased approximately two-thirds. The microphone can be placed close to reflecting surfaces without objectionable effects if the rear side of the microphone is toward the reflecting surface. This is Particularly valuable in small broadcast studios.

It is desirable to experiment with microphone Placement and orientation in order to secure the greatest benefits from the unidirectional character-

istic.

VOLTAGE SENSITIVITY:

MODEL 55AV -

MODEL 55BV - 74db below 1 volt per bar open circuit,

MODEL 55CV - 55.5 db below 1 volt per bar when load-

RECOMMENDED LOAD IMPEDANCE:

MODEL

Code Word Net Wt. Less Cable Shipping Weight

Cable Two- Two-

Height, Overall (a)* Height, Case

Width

Thickness Finish Satin Chrome

The expression "cardioid type" response simply means that the horizon-

tal polar characteristic approximates

a cardioid. There is a wide, useful

SPECIFICATIONS

62/8 db below 6 milliwatts for 10 bar signal when loaded with 35-50 ohms.

or 63.8 db below 6 milliwatts for 10 bar

signal when loaded with 200-250 Ohms. ed with 100,000 ohms or more. This is

equivalent to 1.8 millivolts per bar

across 100,000 ohms or more.

MODEL 55AV - 35-50 ohms. MODEL 44BV - 200-250 Ohms. MODEL 44CV - 100,000 ohms or more.

Patented by Shure Brothers

55AV 55BV

RUVAK 2¾ lb. 3½ lb.

Conduct or

(h)* (b)*

(c)*

* See Fig. C.

12 ft.

RUVAD 2¾ lb. 3½ lb.

12 ft.

Conductor Conductor 7-25/32" 4- 7/16"

3- 3/16" 3- 9/16"

55CV RUVAG

2¾ lb. 3¼ lb.

12 ft.

Single

FREQUENCY RESPONSE OF 55V SERIES MICROPHONES AT VARIOUS DISTANCES FROM THE SPEAKER'S LIPS

GUARANTEE:

free from electrical and mechan-

ical defects for a period of one year from date of shipment from the factory, provided all instructions are complied with

fully. In case of damage, re-

turn the microphone to the fac-

tory for repairs. Our guarantee

is voided if the microphone case

is opened.

Each microphone is guaranteed to be