Electro-Voice CDP-848AT EDS User Manual

General Product Description

Model 848AT is a wide-range, integrated horn and driver system
with a single driver unit having two coaxial horns coupled to opposite
sides of the driver diaphragm.

The folded construction of the rear horn coupled with the smaller
dimensions of the front horn, present a 1,000 Hz acoustic crossover.
This separation of frequencies provides a more extended high
frequency response and cleaner sound.

The 150° horizontal by 110° vertical dispersion pattern is beneficial
in many applications requiring a wide coverage pattern.
Furthermore, excellent loading is maintained to a low-frequency
cutoff of 200 Hz.

Architects’ and Engineers’ Specifications

The loudspeaker shall be of the integrated driver and horn style,
utilizing two coaxial horns coupled to opposite sides of the driver
diaphragm and a larger horn compression molded from fiberglass,
a zinc die-cast front horn with phenolic-constructed inner horns.
The driver uses a high-temperature rated 1.5-inch diameter voice
coil.

The axial frequency response will extend from 260-10,000 Hz and
the horn shall exhibit a low-frequency cutoff of 200 Hz. Sound
pressure level will be 105 dB (1 W/1 M) with a 500-5,000-Hz pink
noise signal applied, and the horn will produce a horizontal
beamwidth of 150° and a vertical beamwidth of 110° at 2 kHz. The
horizontal coverage shall be constant over the frequency range of
3 kHz to 10 kHz.

The loudspeaker shall be compression-molded fiberglass capable
of satisfactory mechanical performance in the temperature range
from -40°C to +40°C and not subject to sunlight embrittlement. Other
major external speaker parts shall be die-cast zinc and finished in
gray polyester paint to match the molded horn parts. All components

848AT

Compound Diffraction

Projector

COMMERCIAL

shall be resistant to damage from weather, moisture and fungus.

A steel swivel bracket capable of providing either vertical or horizontal
installation and a variety of adjustments, is provided.

The loudspeaker shall be 52.0 cm (20.5 in.) high, 26.5 cm (10.5 in.)
wide and 54.6 cm (21.5 in.) long.

The loudspeaker shall be the 848AT, which includes a 70V/25V
transformer and weighs no more than 7.0 kg (15.5 lb).

Specifications:
Frequency Response:

..................................... 260-10,000 Hz ±5 dB (see Figure 3)

Power Handling, 8 Hours, 6 dB Crest Factor:

....................................... 30 watts (500-5,000 Hz pink noise)

Transformer Taps and Impedances:

............................................................................ See Table 1

Sound Pressure Level at 1 Meter 1 Watt Input Averaged, Pink
Noise Band-Limited from 500-5,000 Hz:

.................................................................................... 105 dB

Horizontal Beamwidth:

150° at 2 kHz (see Figure 2)

Vertical Beamwidth:

110° at 2 kHz (see Figure 2)

Directivity Factor R

........................................................................... 7.4 @ 2 kHz

Usable Low-Frequency Limit:

.................................................................................... 200 Hz

(Q):

θ θ

θ

θ θ

Construction:

Large fiberglass compression molding with gray finish, front horn of
gray die-cast zinc and phenolic compression-molded innerhorns
with steel “U” bracket

Voice Coil Diameter:

.................................................................... 3.81 cm (1 .5 in.)

Magnet Weight:

...................................................................... 0.28 kg (0.62 lb)

Magnet Material:

...................................................................... Strontium ferrite

Flux Density:

...................................................................................... 1.25 T

Dimensions,

Height: .......................................................... 52 cm (20.5 in.)

Width: ......................................................... 26.5 cm (10.5 in.)

Depth: ............................................................ 51 cm (20.0 in.)

Net Weight:

....................................................................... 7.0 kg (16.0 lb)

Shipping Weight:

....................................................................... 8.2 kg (18.0 lb)

Installation

As shipped, the “U” bracket is in position for vertical mounting. For horizontal
dispersion, (or for mounts where the bracket mounting holes must be
vertical), move bracket to the rear mounting position. The horn can be
mounted in a variety of horizontal and vertical configurations by using
adjustments of the swivel connections (bracket to horn).

Polar Response

The directional characteristics of the 848AT, with driver attached, were
measured by running a set of horizontal/vertical polar responses in a large
anechoic chamber at each one-third-octave center frequency. The test signal
was one-third-octave, pseudo-random pink noise centered at the indicated
frequencies. The measurement microphone was placed 6.1 m (20 ft) from
the horn mouth, while rotation was about the waveguide geometric apexes.
These axes of rotation are quite close to the apparent (acoustic) apexes
across the frequency range of measurement. Errors attributable to the slight
differences between the geometric and acoustic apexes are reduced to an
inconsequential level by the relatively long, 20-foot measuring distance.
The horn was suspended freely with no baffle. The polar plots shown in
Figure 1 display the results of those tests. The center frequency is noted on
each plot. The wider plot on each chart is the horizontal polar (-) and the
narrower plot is the vertical polar (---).

Beamwidth

A plot of the 848AT 6 dB-down total included beamwidth angle is shown in
Figure 2 for each one-third-octave center frequency.

Frequency Response

Figure 3 shows the axial frequency response of the 848AT. It was measured
at a distance of 1 meter, using a swept sine wave.

Transformer

A transformer is installed in the driver housing. Power taps for the transformer
are listed in Table 1.

Low-Frequency Driver Protection

When frequencies below the low-frequency cutoff for the horn assembly

are fed to the driver, excessive current may be drawn by the driver. For
protection of the driver, amplifier and transformer, capacitor(s) in series
with driver or transformer primary is recommended. Table 1 indicates
recommended values. The values shown are for 200 Hz. Values for other
frequencies can be determined by using the formula:

= Values shown in the following table

C

C

x 200

200

C =

[

Table 1. Series Protection Capacitors for 200 Hz and Below

.seniLtloV-07seniLtloV-07

rewoPecnadepmIecnaticapaCecnadepmIecnaticapaC

W036615

W513332

W85261

W405215.0

W2- - 2132

W1- - 5261

W2/1- - 05215.

200

]

f f = New Frequency

fm

fm

fm

fm

--

--

--

6515

fm

fm

fm

fm

848AT Beamwidth vs. Frequency

Figure 1

848AT Polar Response

USA 12000 Portland Ave South, Burnsville, MN 55337, Phone: [phone], FAX: [phone]
Canada 705 Progress Avenue, Unit 46,Scarborough, Ontario, Canada, M1H2X1,Phone: [phone], FAX: [phone]
Switzerland Keltenstrasse 11, CH-2563 IPSACH, Switzerland, Phone: [phone]. FAX: [phone]
Germany Hirschberger Ring 45, D94315, Straubing, Germany, Phone: [phone], FAX: [phone]
France Parc de Courcerin, Alle Lech Walesa, Lognes, 77185 Marne La Vallee, France, Phone: [phone], FAX: [phone]
Australia Unit 23, Block C, Slough Business Park, Slough Avenue, Silverwater, N.S.W. 2128, Australia, Phone: [phone], FAX: [phone]
Hong Kong Unit E & F, 21/F, Luk Hop Industrial Bldg., 8 Luk Hop St., San PO Kong, Kowloon, Hong Kong, Phone: [phone], FAX: [phone]
Japan 2-5-60 Izumi, Suginami-ku,Tokyo, Japan 168, Phone: [phone], FAX:[phone]
Singapore 3015A Ubi Rd 1, 05-10, Kampong Ubi Industrial Estate, Singapore 408705, Phone: [phone], FAX: [phone]
Mexico Av. Parque Chapultepec #66-201, Col. EI. Parque Edo. Mex. 53390, Phone: [phone], FAX: [phone]
UK 4, The Willows Centre, Willow Lane, Mitcham, Surrey CR4 4NX, UK, Phone: [phone], FAX: [phone]
Africa, Mid-East 12000 Portland Ave South, Burnsville, MN 55337, Phone: [phone], FAX: [phone]
Latin America 12000 Portland Ave South, Burnsville, MN 55337, Phone: [phone], FAX: [phone]

www.electrovoice.com • Telex Communications, Inc. • www.telex.com

© Telex Communications, Inc. 02/2001

Part Number 38109-839 Rev A

Figure 2

848AT Frequency Response

Figure 3

(1 watt at 1 meter)

For customer orders, contact the Customer Service department at

For warranty repair or service information, contact the Service

For technical assistance, contact Technical Support at 866/78 AUDIO

Please refer to the Engineer ing Data Sheet for warranty information.

Specifications subject to change without notice.

U.S.A. and Canada only.

800/392-3497 Fax: [phone]

Repair department at 800/685-2606