Electrovoice evi-28 用户手册

The Electro-Voice EVI-28 full-range loud-

speaker is a 250-watt, two-way, high-effi-

ciency system featuring a new small-for-

mat Vari Intense

®

 horn and dual 210 mm

(8-inch) direct radiators in a compact

vented enclosure.  The EVI-28 combines

patented-Vari Intense

®

 technology with

amplitude-, frequency- and delay-shading

techniques in a fully passive system to a

package that is an industry first in perfor-

mance, size and cost-effectiveness.

The EVI-28 is intended to be used as a

stand-alone full-range system, but may also

be used as the midbass/high-frequency

component in most multi-way loudspeaker

systems.  The primary applications for the

EVI-28 are in smaller rooms, rooms with

lower ceilings than applicable for the

EVI-12 and EVI-15, and as a complemen-

tary  system for upper balconies and un-

der-balcony areas.  The system is optimized

for regular throws on sloped floorplans of

approximately 10 to 15 degrees or long

throws on a flat floorplan relative to the

mounting height.

The high-frequency section of the EVI-28

utilizes a new small-format Vari Intense

®

horn driven by the DH2010A one-inch

throat, wide-bandwidth, titanium-dia-

phragm compression driver. This driver

uses a unique, convex-drive Time Path

TM

phasing plug structure (U.S. Patent

#4,525,604).  The voice coil is coupled to

the diaphragm with EV’s exclusive Reso-

nant Drive

TM

 technology.  This increases

and smooths the high-frequency response

and reduces the amount of internal equal-

ization for flat frequency response past

25,000 Hz.

EV’s self-resetting PRO

TM

 circuit is built into

the crossover network to guard the com-

pression driver from damage.  If input

power to the driver exceeds the nominal

rating, the pro circuit is activated, reduc-

ing the power delivered to the driver by 6

dB.  The system will remain in this mode of

operation until input power is reduced to a

safe level.

The optimally vented bass section of the

EVI-28 is designed using Thiele-Small

parameters for efficient performance to

below 60 Hz.  The dual proprietary 210-mm

(8-inch) high power, long excursion low fre-

quency drivers deliver outstanding perfor-

mance.  The woofers feature a low-mass

extended 51-mm (2-inch) diameter voice

coil combined with a large magnet struc-

ture, a stiff, high-internal-damping cone

and high-temperature materials for years

of reliable performance.

The EVI-28 full-range Vari Intense

®

 loud-

speaker system is the ideal system when-

ever high output full frequency range ma-

terial must be reproduced for balconies,

cinemas, distributed systems and smaller

rooms in churches, gymnasiums, auditori-

ums, hotels and civic centers.

The combination of dual 210 mm (8-inch)

woofers, a wide-bandwidth high-frequency

driver and an equalized, delay-, frequency-

and amplitude-shading crossover results

in the wide and smooth overall response

shown in Figure 1. The EVI-28’s long-throw

axial frequency response was measured in

Electro-Voice’s large anechoic chamber at

a distance of 10 feet with a swept sine-

wave input of 4 volts.  Figure 1 has been

averaged and corrected for 1 watt/1 meter.

The polar response of the EVI-28 speaker

system at selected one-third-octave band-

widths is shown in Figure 2.  These polar

1. The use of Vari Intense

®

 horns is protected by U.S. patent

#5,020,630.