Biamp EQ28X-8 User Manual

EQ281/8 & EQ282/8

Digitally Controlled

1/3-Octave Equalizers

operation manual

®

6/12/98

Biamp Systems, 10074 S.W. Arctic Drive, Beaverton, Oregon 97005 U.S.A. [phone] http://www.biamp.com

an affiliate of Rauland Borg Corp.

EQ281/8 & EQ282/8

TABLE OF CONTENTS

Front Panel
Rear Panel
Setup
Logic Inputs
RS-232 Control
Applications
Specifications & Block Diagram
Warranty

pg. 2
pg. 3

pgs. 4~6

pg. 7

pgs. 8~9

pgs. 10~11

pg. 12
pg. 13

INTRODUCTION

ADVANTAGE® EQ281/8 & EQ282/8 provide one or two channels of digitally
controlled 1/3-octave equalization in a single rack-space unit. Input levels and
28 filter bands, as well as high-pass & low-pass filters, are all adjusted via
computer. Eight presets (per channel) are recalled via contact-closures, third­party controllers, or computer. Filter design utilizing Constant-Q technology
guarantees precise system tuning with less filter interaction, better filter
combining, and constant filter bandwidth at any setting. EQ281/8 & EQ282/8
are covered by a five-year warranty.

EQ281/8 & EQ282/8 features include:

♦

single-channel (EQ281/8) & dual-channel (EQ282/8) models

♦

28 digitally controlled filters (per channel) on ISO frequencies

♦

Constant-Q technology provides precision system tuning

♦

filters adjustable ±12dB in 1dB steps or ±6dB in 0.5dB steps

♦

channel input levels adjustable ±12dB in 1dB steps (plus off)

♦

high-pass filters (12dB per octave) adjustable 9.1Hz~171.9Hz

♦

low-pass filters (12dB per octave) adjustable 1.9kHz~34.7kHz

♦

eight non-volatile memory presets available (per channel)

♦

logic inputs allow selection of presets via contact-closures

♦

RS-232 serial port for computer or third-party controllers

♦

PC control software for Windows® 95 & serial cable included

♦

device number switch & link port for controlling multiple units

♦

baud rate switch provides choice of communications rates

♦

front panel indicators for peak, bypass, & selected presets

♦

balanced inputs and outputs on plug-in barrier strip terminals

♦

optional external pink-noise ‘masking’ generator (PNG200)

♦

modular ±12 Volt DC Out jack for powering external devices

♦

incorporates AES recommended grounding practices

♦ marked and UL / C-UL listed power source
♦ covered by Five-Year "Gold Seal" Warranty

?

After reading this manual, if you have any questions or need technical

assistance, please call Biamp Systems toll-free 1-800-826-1457.

E-mail: [e-mail] Web-Site: www.biamp.com

☎

1

FRONT PANEL

preset

ADVANTAGE EQ 281/8

Digitally Controlled EQ

onbypasspeak

Preset: This seven segment LED display indicates which
preset is currently selected. There are eight presets available
(per channel), which can be recalled from non-volatile memory
via RS-232 or Logic Input control. Each preset stores settings
for input level, 28 filter bands, a high-pass filter, and a low-pass
filter. These settings are adjusted, and presets are stored, via

Peak: This red LED indicates output level has reached +14dBu
balanced (+8dBu unbalanced). When the Peak indicator lights,
10dB of headroom remains before clipping. If increased signal
levels or equalizer adjustments cause the Peak indicator to light
frequently, reduce the equalizer input level to avoid distortion

caused by overdriving the equalizer output section.
RS-232 control, using the PC Control Software and serial cable
provided with the equalizer (see Setup on pg. 4). The equalizer
may also be controlled via RS-232 from third-party controllers.

Bypass: This red LED indicates the equalizer has been

bypassed via RS-232 control. When bypassed, all filters are

temporarily set flat, the high-pass & low-pass filters are set to

their extremes (9.1Hz & 34.7kHz respectively), and the equalizer

input levels are set to unity gain (see Setup on pg. 6).

On: This red LED indicates power is applied to the equalizer.

preset

Channel 1

preset

Channel 2

ADVANTAGE EQ 282/8

Digitally Controlled EQ

onbypasspeakbypasspeak

2

27V

~

50/60 Hz

15 watts

class 2 wiring

27V

~

50/60 Hz

15 watts

class 2 wiring

DC out

DC out

16

32

8

device #

16

32

8

device #

REAR PANEL

output

input

124

serial port

124

serial port

link port

link port

9600

2400

last

baud rate

9600

2400

last

baud rate

19200

19200

logic inputs

logic inputs

output

channel 2

input

BIAMP SYSTEMS

Portland, Oregon

an affiliate of

Rauland-Borg Corp.

MADE IN U.S.A.

BIAMP SYSTEMS

Portland, Oregon

an affiliate of

Rauland-Borg Corp.

MADE IN U.S.A.

output

channel 1

input

AC Power Cord: The power transformer provides 27 Volts AC
to the equalizer, and is detachable via a 5-pin DIN connector.
The equalizer has two internal ‘self-resetting’ fuses (there are no
user servicable parts inside the unit). If the internal fuses blow,
they will attempt to re-set after a short period. However, this
may be an indication that the equalizer requires service.

Baud Rate: This 6-gang DIP switch allows an equalizer to be

assigned a specific communications baud rate. Baud rates

available are 2400, 9600, & 19200 bps. The factory default is

9600 bps. Only one baud rate should be selected at a time, by

raising the corresponding switch. The two switches on the far

right are not used. The switch on the far left (labelled ‘last’) is

used when connecting multiple devices in a ‘Link Port to Serial
DC Out: This 6-pin Modular jack supplies ±12 Volts DC, for
powering external accessory devices. The EQ281/8 DC Out
provides up to 100mA maximum current. The EQ282/8 DC Out
provides only 10mA maximum current.

Device #: This 6-gang DIP switch allows an equalizer to be
assigned a specific device number. Up to 64 different device
numbers (0~63) may be assigned to allow RS-232 control of
multiple ADVANTAGE

®

products in a common system. From

the factory, an equalizer is assigned Device # 1.

Port’ configuration (see Link Port). From the factory, the ‘last’

switch is up. When connecting multiple devices, the ‘last’ switch

must be switched down on all devices except the final (‘last’)

device in the system (the device with no Link Port connection).

Logic Inputs: This 25-pin Sub-D (female) connector provides

16 logic input terminals, plus 9 ground terminals (see Logic

Inputs on pg. 7). Once equalizer settings are adjusted (and

presets are stored) via RS-232 control, the Logic Inputs can be

used to recall presets from non-volatile memory using simple

switches or contact-closures. The EQ281/8 Logic Inputs have
Serial Port: This 9-pin Sub-D (male) connector provides an
RS-232 Serial Port for remote control via computer or third-party
controllers (see RS-232 Control on pg. 8). The Serial Port has
the following pin assignments (left-to-right & top-to-bottom): Pin

1) not used; Pin 2) Receive Data (RxD) input; Pin 3)
Transmit Data (TxD) output; Pin 4) Data Terminal Ready
(DTR) output; Pin 5) Ground; Pin 6) not used; Pin 7)
Request To Send (RTS) output; Pin 8) not used; Pin 9) not
used. PC Control Software and a serial cable are provided for
programming via Windows

®

95 (see Setup on pg. 4).

NOTE:

The Serial Port can also transmit commands which are received
via the Logic Inputs (see Setup on pg. 5).

the following pin assignments (right-to-left & top-to-bottom):

Pins 1~8) recall Presets 1~8; Pins 9~16) no operation; Pins

17~25) switch ground points. The EQ282/8 Logic Inputs have

the following pin assignments (right-to-left & top-to-bottom):

Pins 1~8) recall Presets 1~8 (channel 1); Pins 9~16) recall

Presets 1~8 (channel 2); Pins 17~25) switch ground points.

Logic Input functions may be programmed using the PC Control

Software and serial cable provided with the equalizer (see Setup

on pg. 4).

Output: These plug-in barrier strip terminals provide a

balanced line-level output (per channel). For balanced

connections, wire high to (+), low to (-), and ground to (
Link Port: This 9-pin Sub-D (female) connector provides a Link
Port for RS-232 control of multiple ADVANTAGE

®

products (see

RS-232 Control on pg. 9). The Link Port of one device simply

unbalanced connections, wire high to (+) and ground to (

leaving (-) unconnected. Signal level will be reduced by 6dB

when outputs are unbalanced.
connects to the Serial Port of the next device (and so forth).
Link cables are available as an option (Biamp #909-0057-00).

NOTE: All but the final device in a system should have its ‘last’
switch down (see Baud Rate)

. The Link Port has the following
pin assignments (right-to-left & top-to-bottom): Pin 1) not used;
Pin 2) Transmit Data (TxD) input; Pin 3) Receive Data (RxD)
output; Pin 4) not used; Pin 5) Ground; Pin 6) not used; Pin

7) not used; Pin 8) not used; Pin 9) not used.

NOTE: The

Input: These plug-in barrier strip terminals provide a balanced

line-level input (per channel). For balanced connections, wire
high to (+), low to (-), and ground to (
connections, wire high to (+), and ground to both (-) & (
Input level is adjustable via RS-232 control, and has a range of
±12dB in 1dB steps, plus off.

Link Port can also transmit commands which are received via
the Logic Inputs (see Setup on pg. 5).

ý

). For

ý

ý

). For unbalanced

ý

). The

),

3

SETUP

All equalizer parameters are adjustable using the Windows® 95 'PC Control Software' and serial cable provided with the unit. The PC
Control Software provides programs for the EQ281/8 & EQ282/8, as well as other ADVANTAGE® products. The equalizer programs
include three different control screens (Main
Once the software is started (and Comm Port Configuration is set), the three control screens are accessable through the drop-down menus
at the top of the opening screen. The Main screen appears whenever an equalizer file is opened. Button Definition
Options screens are then available from the Configure EQ282/8 (EQ281/8) menu. The File menu provides functions such as open, close,
save, etc. The Edit menu allows copy/paste & flat-curve functions. The Settings menu recalls the Comm Port Configuration screen. The
Window menu arranges the active product screens. The Help menu explains the available adjustments. To install PC Control Software:
Select ‘Run’ from Windows® 95 ‘Start’ menu, and enter A:\SETUP. System Requirements: Windows® 95 with 8M of RAM & 2M of available
hard disk space (serial port required for ‘on-line’ operation).

, Button Definition, & Configuration Options), which are described on the following pages.

& Configuration

MAIN SCREEN

The Main Screen is used to adjust the equalizer (channel) input level, 28 filter bands, high-pass filter, and low-pass filter settings, as well as to
store & recall eight memory presets. Adjustments are made with the computer mouse (or keyboard). Settings are adjusted by dragging the
corresponding ‘faders’ (or left-clicking the arrow buttons). Each filter band fader provides 25 gain steps, in 1 dB increments (±12dB). Left-clicking
on +/-12 dB will instead select 0.5 dB increments (±6dB). Left-clicking above or below a fader will adjust the gain three steps at a time. High Pass
& Low Pass filters provide 16 frequency steps. Left-clicking to the left or right of the fader will adjust the frequency 4 steps at a time. The Level
fader provides 26 gain steps (±12dB, plus off). Right-clicking in the filter band area opens a drop-down menu, which allows copy/paste & flat curve
functions. Left-clicking a Preset button will recall the corresponding preset from non-volatile memory (presets are stored automatically). Left­clicking the Bypass button will temporarily bypass filter & level settings (see Configuration Options screen on pg. 6). On the EQ282/8, left-clicking
on Linked Controls allows any equalizer adjustments to affect both channels. This is effective for stereo equalization. After initial adjustments, the
controls may again be un-linked, to allow fine tuning of the individual channels. The title bar across the top of the Main screen will indicate the
Device #, the custom Device Name, and the model of product being controlled. The PC Control Software can operate ‘off-line’ (w ith no product
connected) by opening a ‘new’ file for the desired product. The Device # for ‘off-line’ files is assigned sequentially as a negative number.

4