Biamp VOICECRAFTER User Manual

ADVANTAGE® VOICECRAFTER

and VOICECRAFTER Plus

Acoustic Echo Cancellers

Operation Manual

®

Feb 1/00

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

an affiliate of Rauland Borg Corp.

TABLE OF CONTENTS

Front & Rear Panel Features

Software Control

TTC Control

Configuration

Calibration

Option

Connecting External Equipment

RS232

Applications

Troubleshooting

Third-party Control

Specifications & Block Diagram

Warranty

blankVOICECRAFTER

INTRODUCTION

ADVANTAGE
Acoustic Echo Cancellers, which provide full-duplex speech between 2 or more
locations in video or teleconferencing applications. VOICECRAFTER is a DSP
based device and is easily programmed via Windows
VOICECRAFTERS’ long tail length and fast convergence time allow flawless
adaptation to acoustic changes in a room, without the necessity of continual
training. A second model, VOICECRAFTER Plus, includes a 2-wire (POTS)
card for teleconferencing applications. The VOICECRAFTER and the
VOICECRAFTER Plus are both covered by a 5-year warranty.

VOICECRAFTER features include:

pgs. 2 & 3

pg. 4 & 5

pg. 6

pgs. 7 & 8

pgs. 9 ~ 11

pg. 12

pgs 13 & 14

Pg. 15

pgs. 16 ~ 18

pg. 19

Pg. 20

pg. 21

and

VOICECRAFTER Plus

®

VOICECRAFTER and VOICECRAFTER Plus are tamper proof

®

95/98/NT software.

♦ 2 balanced channel inputs on plug-in barrier connectors

♦ channel input 2 can be configured to accept line level inputs

♦ balanced codec input and output on plug-in barrier connectors

♦ phantom power and trim control on channels 1 & 2 (rear panel)

♦ optional input/output transformers on codec inputs/outputs

♦ model VOICECRAFTER Plus includes 2-wire interface

♦ mono-summing aux interface provided on RCA connectors

♦ 0dB and –20dB nominal codec levels switch selectable

♦ 5 ASIC chips provide long tail length and

fast convergence time

♦ 270 mSec tail length and 250 mSec convergence time

♦ five non-volatile memory presets store all settings

♦ information stored in preset 1 is automatically recalled on power-up

♦ RS-232 serial port & Windows

®

95/98/NT programming software

♦ bi-colored LED’s provide level and peak indication

♦ incorporates AES recommended grounding practices

♦ CE marked and UL / C-UL listed power source

♦ covered by Biamp Systems’ five-year warranty

1

FRONT & REAR PANEL FEATURES

volume mute

FRONT PANEL FEATURES

Volume Control: Volume up and volume down controls adjust the

‘User Volume’ inside the VOICECRAFTER. ‘User Volume’ adjusts
the Main Output level, and the range of ‘User Volume’ is
established by the VOICECRAFTER during a Configuration Train
Cycle.

Mute Switch: This momentary switch toggles the System Mute
mode. When the mute switch is pressed a first time, system mute
is engaged (Send and Receive LED both Blink amber), when the
mute switch is depressed again, the system mute is turned off
(Send and Receive LED’s stop blinking). NOTE: System mute
mutes the channel inputs and the main output, system mute also
disables adaptation of the echo canceller until the system mute is
turned off.

Send & Receive LED’s: These bi-colored LED’s indicate signal
levels inside the VOICECRAFTER. When the LED is green;
indicates that there are normal levels inside the unit. When the
LED is red; indicates a clipping or peak condition in the unit. Send
LED indicates levels being transmitted out of the VOICECRAFTER
(2-wire interface, Codec Output, Aux output). Receive LED
indicates levels being received by the VOICECRAFTER (2-wire
interface, Codec Input, Aux Input). NOTE: The send and receive
LED will both blink amber when the VOICECRAFTER is in a
System Mute Mode. The send and receive LED will both blink
green during a Configuration Train Cycle.

Power Switch & On Indicator: When the Power Switch is
depressed, the adjacent red LED will light indicating power to the
unit is On. Release the Power Switch to turn power off. NOTE:
information is stored into preset 1, upon power-up, the
VOICECRAFTER will recall preset 1. If information is not stored in
preset 1, then the VOICECRAFTER will initiate a Configuration
Train Cycle upon power up.

If

ADVANTAGE VOICECRAFTER

Acoustic Echo Canceller

receivesendupdown

REAR PANEL FEATURES

on

o

AC Power Cord: The power transformer provides 27 Volts AC to
the VOICECRAFTER, and is detachable via a 5-pin DIN
connector. The VOICECRAFTER has two internal ‘self-resetting’
fuses (there are no user serviceable 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 VOICECRAFTER
requires service.

Setup Port: This 9-pin Sub-D (male) connector provides an RS­232 Serial Port for control via computer (default of 9600 baud).
The Setup 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) Communication to Send (CTS); 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
CTS and RTS lines are internally shorted inside the
VOICECRAFTER (these pins do not need to be controlled by the
PC).

Control Port: This 9-pin Sub-D (female) connector provides a
Control Port for RS-232 control (default of 9600 baud) of the
VOICECRAFTER via the VOICECRAFTER TTC or third-party
controllers. The Control Port has the following pin assignments
(right-to-left & top-to-bottom): Pin 1) +5 Volts; Pin 2) Transmit
Data (TxD) output; Pin 3) Receive Data (RxD) input; Pin 4) not
used; Pin 5) Ground; Pin 6) not used; Pin 7) not used; Pin 8) not
used; Pin 9) not used.

2

FRONT & REAR PANEL FEATURES

27V

50/60 Hz

27 watts

class 2 wiring

2-wire Interface: (VOICECRAFTER Plus only.) Connect the
telephone wall outlet to the RJ11 port labeled ‘line’, and connect
an analog telephone to the RJ11 port labeled ‘phone’. The 2-wire
interface can be used at the same time as the codec ports for
adding a telephone call to a videoconference, or it can be used
alone for teleconferencing applications.

Main Out: This plug-in barrier strip provides the balanced Main
Out from the VOICECRAFTER. For balanced output, wire high to
(+), low to (-), and ground to (∇). For unbalanced output, wire
high to (+) and ground to (∇), leaving (-) unconnected. Signal
level will be reduced by 6dB when outputs are unbalanced.

Main Level: This screwdriver adjustable control allows the main
output of the VOICECRAFTER to be adjusted during calibration.
Once the main level is set and the VOICECRAFTER is trained, the
main level control should be left alone.

Aux In & Aux Out: These RCA connectors provide a mono­summing Auxiliary interface for connection to a recording device,
VCR, or a second codec (See page 7 for instructions). The Aux
out connectors are wired so that a stereo signal is split and the
same signal will appear on each RCA connector. The Aux In
connectors are wired so that stereo signals are summed together
into a mono signal at this input .

BIAMP SYSTEMS

~

Portland, Oregon

an affiliate of

Rauland-Borg Corp.

MADE IN U.S.A.

setup

control

phone line

2-wire interface

main out

aux inaux out

codec out

-20dB
0dB

codec

level

codec in channel 2 channel 1

inputs

trimlevel

+10

trim

VOICECRAFTER

+10

Codec Out: This plug-in barrier strip provides the balanced Codec
Out from the VOICECRAFTER. For balanced output, wire high to
(+), low to (-), and ground to (∇). For unbalanced output, wire
high to (+) and ground to (∇), leaving (-) unconnected. Signal
level will be reduced by 6dB when outputs are unbalanced.

Codec In: This plug-in barrier strip provides the balanced Codec
Output from the VOICECRAFTER. For balanced input, wire high
to (+), low to (-), and ground to (∇). For unbalanced input, wire
high to (+) and ground to both (-) & (∇).

0 dB / -20dB: This push button switch changes the nominal level
of the codec input and output to either –20dB or 0dB, (switch out is
–20dB, switch in is 0dB) allowing proper interface with many
different codecs. The VOICECRAFTER has an internal +/-12dB of
adjustment via software (see page 4). NOTE: Check the
documentation of your specific codec before installation.

Channel Inputs 1 & 2: These plug-in barrier strips provide the
balanced mic input to the VOICECRAFTER. Input 2 can be set for
balanced or unbalanced line level signals via software selection
(see Page 4). For balanced input, wire high to (+), low to (-), and
ground to (∇). For unbalanced input, wire high to (+) and ground
to both (-) & (∇). Internally, 12 Volt phantom power is available
and is always on, unless line level input is selected via software
on input 2.

Channel Trim & +10 Indicator: The Trim controls adjust gain at
the respective inputs to compensate for different signal levels. For
best performance, set Trim so only occasional peaks in signal level
activate the +10 Indicator.

3

SOFTWARE CONTROL

VOICECRAFTER and VOICECRAFTER Plus parameters are all adjustable using the BiampWin Windows® 95/98/NT 'PC Control Software'
and serial cable provided with the unit. The PC Control Software provides programs for various ADVANTAGE
VOICECRAFTER (Plus). Once the software is started (and Comm Port Configuration is set), the control screens are accessed via the
drop-down menus at the top of the opening screen. The File
recalls the Comm Port Configuration screen. The Window
available adjustments. To install PC Control Software

menu provides functions such as open, close, save, etc. The Settings menu

menu arranges the active product screens. The Help menu explains the

: Select ‘Run’ from Windows® 95/98/NT ‘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). The title bar
across the top of the Main screen will indicate model of the VOICECRAFTER being controlled. The PC Control Software can operate ‘off­line’ (with no product connected) by opening a ‘new’ file for the desired product.

®

products, including the

MIX SCREEN

The Mix Screen is used to adjust VOICECRAFTER input/output levels, store/recall of five memory presets (preset 1 being the power-up
preset) and to initiate training. Adjustments are made with the computer mouse (or keyboard). Input & output levels are changed by
selecting the desired level via the pull down menu.
Channel 1 & 2

These sections are for setting up the channel inputs on the VOICECRAFTER. Setting the desired level also changes the
default gain (which is used for a train). NOTE: there is an analog screwdriver trim pot on the rear panel for making input adjustments.
Aux

selects the mode of the Aux port, and sets the desired levels for the Aux port interface. (See page 13)

Preset

buttons recall the corresponding presets from non-volatile memory.

Store

button opens a menu for storing current settings in any of the Presets 1~5, or deleting the preset stored into preset #1. Each preset
saves settings established by a Configuration Train Cycle. If settings are stored into Preset 1, then Preset 1 will be recalled upon power-up.
Averages
AutoAdaptation

displays the DSP averages calculated by the VOICECRAFTER, these values are continually updated every second.

selects the operation of the AutoAdaptation function, Fully Enabled, Gain Disabled, and Fully Disabled. NOTE: Gain
adjustments on Channel 1/ 2 and Main Output cannot be made unless AutoAdaptation is set to Fully Disabled. Gain Disabled: stops the
VOICECRAFTER AGC from making gain changes to the Mic inputs, Codec Input, and Main Output.
Main Output
Codec
Dial Pad
2-Wire

selects the level of the main output, Noise turns on/off the internal white noise generator

adjusts the level of the Codec Input and Codec Output.

is for dialing out of a VOICECRAFTER Plus via the 2-wire port.

turns on and off the 2-wire port, puts a call on hold, or performs the flash function, as well as selecting either pulse or DTMF dialing
modes. Click on DTMF mix to hear DTMF tones through the speakers (checked is enabled). After selecting the 2-wire On/Off button,
either click each desired number to be dialed out, or press the corresponding numbers on the keyboard to dial the number. After the call is
complete, click on the 2-wire On/Off button again.

4

SOFTWARE CONTROL

Train Screen

The train screen is accessed by clicking on the Train button located in the AutoAdaption section of the Mix-screen.

The Train screen is used to set the AERL Target, initiate a Config Train, a Refresh train, or select the Power Up options of a
VOICECRAFTER or VOICECRAFTER Plus.

AERL Target
9~11, for more information)

Refresh
room.

Config
room. A ‘Training Complete’ prompt pops up after a Config train, click ‘OK’ and then the training results are displayed in the Train section
of the Train Screen.

Power Up Options

NOTE: In order for Power Up Options to take effect, settings must be stored into Preset 1.

Select the desired AERL target (0-20dB) via the pull-down menu before initiating a Config train. (See Calibration, pages

begins a refresh train; two quick bursts of white noise are generated for the VOICECRAFTER to build an acoustic model of the

begins a configuration train; white noise is generated and the VOICECRAFTER takes measurements and adjusts levels for the

selects the mode of training performed upon a power-up. Select between a Config Train, Refresh Train, or a Skip Train.

Password Screen

This screen allows a password to be set, preventing un-authorized tampering with the Echo Cancellers settings. Type in the desired
password, then re-type the password to verify. The password can be any combination of alpha or numeric characters up to 32 characters

Advanced Settings

The advanced settings screen is used to diagnose the VOICECRAFTER and VOICECRAFTER Plus units. A qualified technician should
only access the Advanced Settings screen, as parameters changed in this screen can adversely effect the performance of the echo
canceller. Access the Advanced screen by clicking on the VOICECRAFTER pull-down menu (located at the top of BiampWin, then select
the Advanced Setings option.

5

TTC CONTROL

The VOICECRAFTER TTC (Table Top Controller) allows convenient control of the day-to-day operations of the VOICECRAFTER and
VOICECRAFTER Plus. The TTC features a 15’ attached cable for connecting the TTC to the Control Port on the VOICECRAFTER. To

add a longer cable (up to 50’), remove the 4 screws on the bottom of the TTC. Remove the existing cable from the TTC. Feed the ‘pigtail’
end of the connector through the hole; attach the strain relief and the ferrite bead from the old cable to the new cable on the inside of the
TTC. Attach the wire connected to pin 1 (DB9M) to the terminal labeled ‘+V” on the TTC. Attach the wire connected to Pin 3(DB9M) to the
terminal labeled ‘Tx’ on the TTC. Attach the wire connected to pin 5 (DB9M) to the terminal labeled ‘Gnd’ on the TTC. Replace the bottom
cover and the 4 screws. Attach the DB9M to the Control Port of the VOICECRAFTER (Plus).

C

T

T

E

R

T

F

A

R

C

E

C

I

O

V

E

G

A

T

N

A

V

D

A

12

VOLUME

MUTE

VCR MUTE

VOICECRAFTER TTC

1

1

GHI

4

4

PRS

7

7

34

PRESETS

ABC

2

2

JKL

5

5

TUV

8

8

OPER

0

0

5

DEF

3

3

MNO

6

6

WXY

9

9

#

#

®

PHONE

HOLD / PAUSE

FLASH / STORE

SPEED DIAL

Connect the TTC to the Control Port of the VOICECRAFTER (Plus). The VOICECRAFTER provides the necessary power for the TTC.

Preset Recall

– Recalls up to 5 stored presets (Presets must be stored using PC Control Software, and can NOT be stored via the

VOICECRAFTER TTC).

– Adjusts the user volume up and down. The VOICECRAFTER sets the limits on user volume increase and decrease amounts to

Volume
ensure that the VOICECRAFTER can adapt to changes.

– Engages the System Mute Mode (Channel inputs and Main Output is muted). LED flashes amber when VOICECRAFTER is

Mute
muted, and remains off during normal operation.
VCR Mute

– Mutes and un-mutes the Aux port in VCR mode for switching between Record and playback functions. This button will have
no effect if the VOICECRAFTER is in Bridged Mode.
Dialing Pad

– When the 2-wire interface is connected, these numbers (similar to any telephone) allows dialing directly from the

VOICECRAFTER Plus.

– Connects and dis-connects the 2-wire interface. When the red LED is on, the 2-wire connection is made, when the red LED is off,

Phone
the 2-wire interface is ‘hung-up’.
Hold/Pause

– Puts the 2-wire interface on hold. This button can be used to put a 2-wire conversation on hold, yet still maintains a 4-wire
connection (useful in Video- and Audio-conferencing situations). Pause function is used in speed dialing.
Flash/Store

–

Flash Engages the Flash function (if available –Check with your phone system provider) to answer call waiting or engage 3-way calling.
Store Used for setup of Speed Dial. In a dis-connected state this button is used to store Speed Dial numbers.

Speed Dial

– When pressed, followed buy a 0~9 on the Dialing pad, will connect the 2-wire interface and dial the stored number.

Storing Speed Dial Numbers

1. When a conference call is not connected, hold the Speed Dial button until the Mute and VCR Mute LED begin to blink.

2. Press the memory location desired (0-9), followed by the desired number to be dialed (up to 16 characters), then press Flash/Store

button.

3. The LED above the Phone button will blink signaling that another speed dial number is ready to be stored, repeat step 2, or press

Speed Dial to cancel.
NOTE: The pause button is used to insert a delay between numbers dialed. This is useful when dialing out of a local PBX. Example:
Press and hold Speed Dial button, enter memory location then 9 to get an outside line, then the Hold/Pause button, followed by the number
to be dialed. This inserts the necessary delay for the PBX to obtain an outside line.

6

CONFIGURATION

After all the microphones and speakers are connected to the VOICECRAFTER, the unit needs to be calibrated and trained before a
videoconference or teleconference can be held. Training is how the VOICECRAFTER is configured for proper operation, setting
microphone and speaker gains for optimum performance, by means of the Control Software. The VOICECRAFTER uses white noise to
establish gain settings as well as to make an acoustic model of the room for echo cancelling purposes. There are 2 modes of training for
the VOICECRAFTER.
Configuration Train
updates the H-register* in this training mode.
Refresh Train
Train cycle.
(* H-register: A memory location where an acoustic model of the room is created and stored for use in the echo canceling process.)

After a Configuration Train cycle is initiated by means of the BiampWin software, the VOICECRAFTER will provide resulting information
from the Train cycle. The VOICECRAFTER will send out an AERL* value and an ERLE* value.

*AERL (Acoustic Echo Return Loss) is the difference in level between signal coming out of the speakers and signal which is picked up by
the microphones. VOICECRAFTER calculates an AERL by subtracting what is received by the echo canceller (EC_Si*) from what is sent
out to the speakers (EC_Ri*). The formula is (EC_Ri - EC_Si = AERL). An AERL target is factory set for +10dB, with a range of 0dB ~
+20dB, which is adjustable via software. This number is used as the basis for a Configuration Train cycle. This number represents the
amount of attenuation that the VOICECRAFTER expects to see due to the normal room acoustics. AERL should be within +/-2dB of set
target. If the VOICECRAFTER fails to achieve an AERL greater than 0dB, the VOICECRAFTER will display a train alarm.
(*EC_Si - the amount of signal fed to the echo canceller from Channel 1 and Channel 2.)
(*EC_Ri - the amount of signal fed to the echo canceller from Codec In, 2-wire in, and Aux In.)

: Training mode where VOICECRAFTER sets microphone gain and speaker gain settings. The VOICECRAFTER also

: Training mode where the H-register* is updated. VOICECRAFTER reverts to settings from the most recent Configuration

*ERLE (Echo Return Loss Enhancement) is an indication of the amount of VOICECRAFTER processing required for the room. The ERLE
is a snapshot measurement taken at the end of a Configuration Train cycle. The VOICECRAFTER calculates ERLE by taking what is
received by the echo canceller (EC_Si) and subtracting what is sent out of the echo canceller (EC_So)*. The formula is (EC_Si - EC_So =
ERLE). For most rooms the ERLE should be 8dB or greater. In some less reverberant rooms a lower ERLE may be acceptable. A low
ERLE in a highly reflective room means that the echo canceller may not be able to adapt quickly to changes in the conference
environment. In a more absorptive room the echo canceller may not need to work as hard and therefore the ERLE can be a lower value
without any effect on the echo cancellers performance.
(*EC_So - the amount of signal fed out of the echo canceller to Codec Out, 2-wire out, and Aux Out.)

ERLE

AERL

Channel Inputs

Ec_Si

To Main output

7

AEC

EC_So

EC_Ri

CONFIGURATION

If the VOICECRAFTER can’t achieve an AERL within +/-2dB of target, the target may need to be raised or lowered depending on the
room. Example: A large room, which produces excessive loudspeaker gain and echo after training, may require the AERL target be
increased. However, a small room, which produces insufficient loudspeaker gain, may require the AERL target to be decreased. After
adjusting the AERL target, the VOICECRAFTER must again be put through a Configuration Train cycle. The room should be quiet during
any training cycle. An EC_Si of less than -35dB is desired for an accurate training cycle, otherwise there is too much ambient noise in
the room due to air handling, ect. Placement of microphones in relation to speakers is essential for proper training values. If a
microphone is too close to a speaker, the VOICECRAFTER may set channel or speaker gains to low, which will affect the AERL.
Channel default settings also play an important part in determining AERL and ERLE values. When connecting a microphone mixer
directly into a VOICECRAFTER, be sure that Channel 2 is set for line level input. The Channel 2 default gain will depend on the output
level of the microphone mixer; the end result being that the EC-Si is approximately –20dB with normal speech or white noise.

AERL and ERLE values can more easily be achieved by properly adjusting Channel gain settings, and by paying attention to appropriate
microphone and speaker placement. NOTE: It is recommended that microphone and speakers be placed apart from each other to
prevent direct coupling between speaker output and mic input (4-5 feet is a good distance). For best performance: If ceiling speakers
are being used, try and use table mics. If ceiling mics are being used, try using a speaker mounted on a wall.

Mix-Minus

When a mixer is connected to both
output signal never be fed back to the VOICECRAFTER input. Therefore, the mixer must provide an output to the local sound
reinforcement system, which includes all signals (near end and far end). In addition, the mixer must also provide an output to the
VOICECRAFTER, which includes only local signals (near end). This is known as a ‘mix-minus’ output.

a VOICECRAFTER and a local sound reinforcement system, it is essential that VOICECRAFTER

8