Electro-voice 205-8A, 205-4T, 205-8T User Manual

General Product Description

The Electro-Voice® 205 is a high quality 4-inch, full-range
loudspeaker for distributed sound systems.

An acoustically transparent dome encloses a small, centrally
mounted free-edge cone which is used to improve
high-frequency dispersion.

The 205 is suitable for use in applications requiring highly
intelligible speech or smooth musical reproduction.

To ensure long-term reliability in installations, the 205-8A is
designed to handle 10 watts continuous power (40 watts
peak) of shaped white noise for eight hours per EIA Standard
RS-426A 1980.

The 205-4T includes a 4 watt transformer, allowing
connection to 25/70.7/100- volt line, with taps of 0.5 to 4
watts.

The 205-8T includes an 8 watt transformer, allowing
connection to 70.7/100- volt line, with taps of 1 to 8 watts.

Architects’ and Engineers’ Specifications

The loudspeaker shall be a ceiling loudspeaker with a
nominal diameter of 128 mm (5.1 in.), an overall depth of
56 mm (2.2 in.) for the 205 and 94 mm (3.7 in.) for the 205­4T, and shall weigh no more than 0.9 kg (2.0 lb) for the 205,

1.3 kg (2.8 lb) for the 205-8T. The voice coil shall have a
nominal diameter of 25.4 mm (1.0 in.) and length of 7.6 mm
(0.3 in.) and shall operate in a gap of not less than 1.0 T
(10,000 Gauss).

The loudspeaker shall exhibit a sensitivity (SPL, 1 watt at 1
meter (3.28 ft) averaged (200 - 4,000 Hz) of no less than 91
dB on axis maintaining an essentially flat frequency
response with 3 dB-down points at 65 Hz and 16,000 Hz in
a two-cubic-foot sealed box in a free field. The half-space

205 Series

4-Inch Full-Range

Ceiling Loudspeakers

COMMERCIAL

reference efficiency shall be 0.8%. The nominal impedance
shall be 8 ohms and the dc resistance shall be 6.5 ohms.
The loudspeaker shall be capable of handling a continuous
10-watt (8.6 volts true RMS) shaped white-noise signal (as
per EIA Standard RS-426A 1980) with a 6-dB crest factor
for eight hours.

The loudspeaker shall be the model 205-8A. When fitted
with a transformer that allows connection to 25/70.7/ 100-volt
systems of 0.5 to 4 watts, the loudspeaker shall be referred
to as the model 205-4T. When fitted with a transformer that
allows connection to 70.7/100-volt systems of 1 to 8 watts,
the loudspeaker shall be referred to as the model 205-8T.

Specifications:

Frequency Response: 90 - 18,000 Hz, ±5 dB (see last page)

Power-Handling Capacity: .......................................... 10 watts

(per EIA RS-426-A 1980 (85 - 15,000 Hz bandlimited pink noise,
6-dB crest factor):

Impedance:

Nominal: .................................................................. 8 ohms

Minimum: ............................................... 6.7 ohms (230 Hz)

Sound Pressure Level: ................................................... 91 dB

(at 1 Meter, 1 Watt Input, 200 - 4,000 Hz Average)

Maximum SPL: ....................................... 101 dB for 10W @ 1M

Voice-Coil Diameter: ...................................... 25.4 mm (1.0 in.)

Magnet Weight: ............................................... 0.32 kg (0.72 lb)

Magnet Material: .................................................Barium Ferrite

Flux Density: ............................................................... 1.0 Tesla

Speaker Frame: .................................. 22-gauge stamped steel

Frame Color: ...................................................................... Black

Dimensions:
205-8A / 205-4T / 205-8T

Diameter: ................................................... 206 mm (8.1 in.)

Height:

205-8A .......................................................... 56 mm (2.2 in.)

205-4T / 205-8T: .......................................... 94 mm (3.7 in.)

Net Weight:

205-8A: ........................................................... 0.9 kg (2.0 lb)

205-4T / 205-8T: ............................................ 1.3 kg (2.8 lb)

Transformer Input:

205-4T ................... 25 or 70.7 volt line (100 volt operation)

205-8T ............................. 70.7 volt line (100 volt operation)

Recommended Connections

T4-502

V52V07V001

W0.4

nworBwolleYneerG

W0.2

deRneerGeulB

W0.1

egnarOeulBteloiV

W50.

wolleYteloiVA/N

nommoC

kcalBkcalBkcalB

smhO8

etihWetihWetihW

nommoC

kcalBkcalBkcalB

T8-502

V07V001

W0.8

nworBdeR

W0.4

deRegnarO

W0.2

egnarOwolleY

W0.1

wolleYA/N

nommoC

kcalBkcalB

smhO8

etihWetihW

nommoC

yerGyerG

The 205 is a nominal 8-ohm impedance loudspeaker with a
10-watt input capability. The 205-4T utilizes a 4-watt, 25/70.7/
100-volt universal line matching transformer with power taps
ranging from 0.50 to 4 watts.The 205-8T utilizes an 8-watt,

70.7/100-volt universal line matching transformer with power
taps ranging from 1 to 8 watts. The transformer is mounted to
the frame and the primary winding is accessible for the user
to select any of the power taps indicated in the following table
for 205-4T. For use with 100-V lines, connect to the 70.7 V
primary winding, and use the table below to determine the
wattage ratings of various secondary winding taps. Do not
use the tap marked 4 W.

All wattages marked for the various taps refer to the load on
the amplifier, with the insertion loss of the transformer being
less than 1.0 dB.

Recommended Enclosures and Baffles

The 205-8A, 205-4T, and 205-8T are designed to fit on
standard 4-inch ceiling speaker baffles. Additionally, these
loudspeakers will accommodate the use of any standard back
enclosure with a diameter of 5.5 inches or greater and a depth
of at least 4.5 inches. Larger back volumes will increase the
low-frequency output. The frequency response of a 205 in a
typical 1.0-cubic-foot and 1.8-cubic-foot back enclosure are
shown on the last page.

Mounting

The 205 may be front- or rear-mounted against either surface
of its mounting flange and requires a 110 mm (4.35 in.)
diameter cutout and a 120 mm (4.72 in.) bolt circle. Normal
fasteners up to 5 mm (0.20 in.) will fit through the eight holes
in the frame. The 205 is designed for mounting on standard
ceiling speaker baffles.