Polycom Vortex EF2201 User manual

Presenting Vortex®Installed Voice Products
Next Generation Voice Conferencing
Application Note
Polycom Installed
Voice Business Group
November 2004

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1VORTEX EF2280/EF2241 FEATURES AND FUNCTIONS .........................................................2
2VORTEX EF2211/EF2210 FEATURES AND FUNCTIONS .........................................................3
3VORTEX EF2201 FEATURES AND FUNCTIONS ....................................................................4
4VORTEX PRODUCTS: WHAT’S NEW..................................................................................5
5SOME QUESTIONS AND ANSWERS .................................................................................6
6SYSTEM BLOCK DIAGRAMS..........................................................................................17
7VORTEX EF2280 INPUTS AND OUTPUTS..........................................................................20
8APPLICATIONS ............................................................................................................23
9AUTOMATIC MICROPHONE MIXING ..............................................................................24
10 AUDIO MATRIXING ...................................................................................................26
11 PRESETS AND MACROS ............................................................................................30
12 SERIAL REMOTE CONTROL.........................................................................................31
13 CONFERENCE COMPOSER SOFTWARE ........................................................................32
14 POLYCOM INSTANTDESIGNER V 2.0.................................................................35
15 FRONT PANEL CONTROL............................................................................................37
16 REMOTE CONTROL: LOGIC INPUT AND OUTPUT PINS...................................................39
17 LINKING MULTIPLE DEVICES......................................................................................40
18 VORTEX EF2280 SPECIFICATIONS ...............................................................................49
Revised: November 2004

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Welcome to Polycom’s Vortex®product line, designed specifically for the challenges of installed room conferencing applications.
The Vortex line currently comprises five products plus a number of accessories, and integrates easily with Polycom voice and video
products for a comprehensive conferencing experience that will please integrators and end users alike.
This paper will cover the key features and capabilities of the following Vortex products:
• Vortex EF2280, a 12 input/12 output, 8 channel acoustic echo and noise canceller with built-in automatic microphone
mixers, parametric EQ’s, AGC’s and matrix mixer.
• Vortex EF2241, an 8 input/8 output, 4 channel acoustic echo and noise canceller with built-in automatic microphone
mixers, DSP based telephone interface, power amplifier, matrix mixer and processing functions.
• Vortex EF2211, a 3 input/3 output, single channel acoustic echo and noise canceller with DSP based telephone interface
and power amplifier and processing functions.
• Vortex EF2210, a 3 input/3 output, single channel acoustic echo and noise canceller with power amplifier and processing
functions.
• Vortex EF2201, a DSP based telephone hybrid for connection to PSTN (analog) telephone lines.
Typical applications for Vortex products include video and audio teleconferencing rooms, distance learning classrooms, boardroom
audio systems, courtroom audio systems, and any facility where conferencing is required or may be necessary in the future.
All Vortex products include our Conference ComposerTM software for Windows®, featuring the Polycom InstantDesignerTM Vortex
setup wizard. We invite you to download the Conference Composer software for your evaluation. You may find it on our website
at www.polycom.com or e-mail us and we will send you a CD-ROM.
For a demo of the Vortex EF2280 or any of our other Vortex products, call the Polycom Installed Voice Business Group anytime at:
1-800-932-2774.
Polycom, Inc.
Installed Voice Business Group
9040 Roswell Road, Suite 450
Atlanta, GA 30350
Phone: [phone]
Fax: [phone]
[email protected]
www.polycom.com

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The Vortex EF2280 is a 12 input/12 output, 8 channel acoustic echo and noise canceller with built-in automatic microphone mixers,
parametric EQ’s, AGC’s and matrix mixer. The Vortex EF2241 is an 8 input/8 output, 4 channel acoustic echo and noise canceller
with automatic mixing, parametric EQ’s, AGC’s, matrix mixer, telephone hybrid and power amp. These products’ key features are:
• Multiple channels of mic/line acoustic echo cancellation (AEC), noise cancellation (NC), and automatic gain control (AGC).
• 48 VDC phantom power on microphone inputs, software selectable.
• 40 dB/second convergence rate on each AEC channel.
• 270 msec tail time.
• 20dB headroom on all channels.
• 12 line level outputs on Vortex EF2280; 8 line level outputs on Vortex EF2241 (0dBu nominal level), user adjustable.
• Polycom patented noise cancellation algorithms remove steady-state noise signals on microphone inputs (and on telephone
line output in Vortex EF2241); user adjustable up to 15 dB of noise reduction.
• 5-band parametric filters for input and output equalization on each of the inputs and outputs.
• Digitally controlled analog trim pots on A/D inputs for precise input level adjustment.
• 24-bit codecs, 32-bit floating-point processing.
• 48kHz sample rate ⇒22 kHz bandwidth on all channels.
• RS-232 for interface to control systems and Conference Composer software.
• 24 configurable logic input pins and 20 configurable logic output status pins.
• High speed, low-delay EF expansion bus links Vortex devices.
• 32 user presets, 16 factory presets, 256 macros (each up to 256 commands).
• Scalable automatic microphone mixer – supports up to 64 microphones or can be arbitrarily split into 2 automixers per Vortex.
• Fully controllable 25x18 cross point main matrix with arbitrary gain on cross-points (1dB increments on level).
• Configurable cross point mix-minus interface from the expansion bus to the main matrix: select only the channels from the bus
that you want!
• Conference Composer software for easy configuration, project management, and project documentation.
• InstantDesigner setup wizard reduces configuration time from hours to minutes – its capabilities will amaze you!
• Front panel LCD for controlling and configuring the product without a computer.
• Internal signal generator for noise masking applications and calibration.

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• Single channel of mic/line acoustic echo cancellation (AEC), noise cancellation (NC), and automatic gain control (AGC).
• 48 VDC phantom power on microphone input, software selectable.
• 2 line level inputs with adjustable input level.
• 40 dB/second convergence rate on each AEC channel.
• 270 msec tail time.
• 20dB headroom on all channels.
• 3 line level outputs (0dBu nominal level), user adjustable.
• Polycom patented noise cancellation algorithms remove steady-state noise signals on mic/line input (and on telephone line
output in Vortex EF2211); user adjustable up to 15 dB of noise reduction.
• 5-band parametric filters for input and output equalization on each of the inputs and outputs.
• Digitally controlled analog trim pots on A/D inputs for precise input level adjustment.
• 24-bit codecs, 32-bit floating-point processing.
• 48kHz sample rate ⇒22 kHz bandwidth on all channels.
• RS-232 for interface to control systems and Conference Composer software.
• 24 configurable logic input pins and 20 configurable logic output status pins.
• High speed, low-delay EF expansion bus links up to 8 Vortex devices with 4 channels per device plus AEC reference.
• 32 user presets, 16 factory presets, 256 macros (each up to 256 commands).
• Conference Composer software for easy configuration, project management, and project documentation.
• InstantDesigner setup wizard reduces configuration time from hours to minutes – its capabilities will amaze you!
• Front panel LCD for controlling and configuring the product without a computer.
• Internal signal generator for noise masking applications and calibration.

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• Echo cancellation 40 dB, total 60 dB, convergence rate 30dB/second.
• Line echo cancellation span 32 msec.
• 20dB headroom.
• Telephony signals are communicated with a Vortex EF2280 over the digital P-bus channel of the EF bus, eliminating the need
for external analog inputs or outputs to/from the Vortex EF2280.
• Polycom patented noise cancellation algorithms remove steady-state noise signals on telephone line output; user adjustable
up to 15 dB.
• Audible ring indication, dialtone, and DTMF signals (user adjustable levels).
• User configurable entry and exit tones.
• Up to 256 speed dial memories.
• Country-specific telephone configuration settings.
• Selectable auto hang-up via loop drop and call progress detection.
• RS-232 for interface to control systems and Conference Composer software.
• 24 configurable logic input pins and 20 configurable logic output status pins.
• Parametric EQ for tailoring sound of telephone line to user requirements.
• Conference Composer software for easy configuration, project management, and project documentation.
• InstantDesigner setup wizard reduces configuration time from hours to minutes – its capabilities will amaze you!
• Front panel LCD for controlling and configuring the product without a computer.

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The Vortex incorporates the latest advances in audio technology for use in audio conferencing applications and more. The
highlights of what makes the Vortex unique are described here.
InstantDesigner v2.0
This powerful setup wizard can help you configure the Vortex products in your installation, including loudspeaker zoning, in a
matter of minutes. Not only will you save time, you’ll be assured that matrix settings, gains and other tricky components of your
setup are accurate. This reduces the chance of service calls later and improves your profitability on the job.
Improved latency specifications
Total latency in a Vortex unit (mic/line inputs to outputs, processing enabled) does not exceed 13 ms. This results in more natural
sounding audio and is better for sound reinforcement applications.
Interoperability with other Polycom products
The Vortex EF2280 and Vortex EF2241 are designed to work easily with the SoundStation VTX 1000TM, Polycom’s unique wideband
conference phone. This product gives users a familiar interface to the phone line and easy control over levels and other system
adjustments. In addition, the Vortex EF2280/EF2241 work seamlessly with the VSXTM 8000 video conferencing system. The VSX
remote can be used to control the Vortex products.
Special product bundles are available that package the Vortex EF2280 or Vortex EF2241 with these Polycom voice and video
products. Ask your Polycom representative for more information.
Noise Cancellation
Polycom owns two patents on our proprietary noise cancellation technology that can eliminate background acoustic noise such as
HVAC, computer noise, projector noise, or any noise with stationary statistics. The noise cancellation not only removes noise, but
also helps the acoustic echo canceller converge faster in noisy rooms. Vortex noise cancellation is user-adjustable from 0 to 15 dB
on all mic/line inputs.
Speech Driven Automatic Gain Control
Each of the microphone/line inputs on the Vortex includes an automatic gain control that has been specifically developed for use
with speech and audio signals. This AGC is controlled by a neural network and uses advanced signal analysis to determine when
to change the gain of the input signal. Unlike some other products, you won’t experience ramping on background noise with the
Vortex! This is a sophisticated tool that we recommend should be enabled at all times. Try it and we think you will agree.

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Acoustic Echo Cancellation (AEC) Questions
What makes the Vortex AEC better?
The Vortex AEC has been designed to get the best trade-off between full-duplex audio (quick interaction of both sides of
a conversation and having both sides hear each other) and removal of echo when both sides of the conversation are
moving about their rooms while both sides are speaking. This is a measure of the doubletalk performance.
Why does the Vortex sound better?
There are several reasons including the full bandwidth of the signal – 22 kHz of bandwidth all the time, the digital trim
pots that adjust the analog gain before the A/D converter – this maximizes the signal to noise ratio and removing the
high frequency hiss you can hear with other devices. The noise cancellation also helps to bring down the ambient room
noise so that the echo canceller can do a better job of adapting to the room acoustics. The AGC also helps the AEC
performance by bringing all the signals to the proper level.
What is room gain and why is it important?
Room gain is the difference in level (in dB) between the outgoing level from the room device to the incoming level to the
room device. In Figure 1, you can see which two points are being used to measure this difference. Factors that affect
room gain are the amount of amplification in the loudspeaker, the amount of gain applied to the microphone inputs, and
how closely coupled the microphones and loudspeakers are.
Room gain is important because the acoustic echo canceller
compares the signal that is sent to the amplifier/loudspeaker to
the signal picked up by the microphones. If the signal picked up by
the microphones is much larger than the signal sent to the
amplifier/loudspeaker (which is the case if the room gain is
positive), then the AEC has a tougher time removing the echo and
may become less full duplex.
How do I know what my room gain is?
The Conference Composer software has a built in mode for determining room gain and can display the room gain just like
signal meter information. Go to the room diagnostics page within Conference Composer and select the Levels button.
On the room diagnostics page you will see the room gain for each microphone and you will also see the amount of gain
(or attenuation) the AGC is applying to each inputs 1 to 8. The room gain measurement is most accurate when the local
talkers are quiet and only the remote site is talking.
Is the Vortex easier to setup than other products?
Yes. Our InstantDesigner wizard beats everything else in terms of speed and accuracy. Even if you opt not to use the
InstantDesigner, it’s still easy to set up a Vortex product. Setting the Vortex input channel gains and the calibration
process is easy because of the room diagnostics page within Conference Composer. You can set input gains more
quickly and get immediate visual feedback as to whether your input gains are set too high or too low. If the AGC is
continually pulling the signal up by 10dB (as indicated by the AGC level meter) then your input gains should be adjusted
AEC
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B
Figure 1. Room gain is measured from output A to input B
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up by 10dB. If the AGC is continually pulling the input channel down by 8dB then your input gain should be adjusted
down by 8dB. It is that easy.
What is convergence speed and why is it important?
Convergence speed is how fast the AEC can adapt and “lock” onto to the local echo and effectively begin removing it.
You can think of convergence speed as the rate at which audio from the remote site played into the local room will be
attenuated by the AEC before being sent back to the remote site. This is related to convergence time, which is the
amount of time it takes the AEC to reduce the echo to some level. With most echo cancellers, before the AEC locks into
the echo, there is some amount of clipping that happens to the out going audio to prevent an echo from being sent back
to the remote side. This clipping makes it difficult to have a natural full-duplex conversation. Because participants in a
room are constantly moving, or the microphones are being moved or muted, or the volume is being changed, the echo
path is always changing. Faster convergence means the AEC can lock onto changes in the room faster and sound better
faster.
Why does the Vortex’s AEC converge faster than everyone else?
It is because we spent more than eight years in the development of our AEC algorithm, and we are continuing to work on
it. We have learned a great deal over this time frame. By tightly integrating the AEC with the noise canceller we can
make better decisions about when to adapt the AEC and when to not adapt. Adapting at the wrong time is worse than
not adapting at all because it is possible to make the echo worse if the AEC trains on the wrong signals, i.e., if it trains
on the local talker’s audio, mistaking it for an echo from the remote side.
What is tail time and why is a longer tail time important?
Tail time is the maximum length of time that an echo may bounce around the local room and still have the AEC recognize
it as an echo of the remote talker’s speech and remove it. Echoes that are longer than the tail time (because of a large
room, room with hard surfaces, etc.) will not get recognized by the AEC and will not be removed. The remote talkers will
always hear a delayed version of their audio if the echo length of the local room is larger than the tail time of the local
echo canceller. A longer tail time is important because it means the echo canceller can handle larger rooms or rooms
with hard surfaces.
Noise Cancellation Questions
How does the Vortex’s noise canceller work?
The Vortex’s noise cancellation system works by looking at the background noise between spoken words and estimating
the noise statistics. Once the system has determined the characteristics of the noise, it then removes the noise from the
input signal. Any subsequent processing, such as in the automixer and matrixer, work with the noise-reduced version of
the signal. The adaptation to the noise happens continuously, so as the background noise changes, such as HVAC is
turned on and off, the system adapts nearly instantaneously to the new noise characteristics.
How is the Vortex’s noise canceller different from other products that say they reduce noise?
Many products say they remove noise by filtering. When this happens, they will also remove any signal in the same
frequency band as the noise. The Vortex noise canceller is different from other products because it uses an adaptive
frequency selective algorithm to remove the noise only where there is noise and to leave the desired signals (speech,
audio, etc.) alone.
What type of noise does it work on?
The Vortex noise canceller works best with steady state signals, i.e., signals that are random, but their randomness can
be thought of as fixed. Examples of this are white or pink noise – the signal is random but the type of randomness is
known, periodic signals such as tones – the signal is steady state, and crowd noise – a large collection of voices, when

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mixed together, sound like random background noise. Certainly combinations of these types of signals can also be
effectively removed such as the noise from power drills – there is a combination of periodic signals and random noise.
The types of noise that the Vortex noise canceller cannot remove include short impulsive noises, like a hammer blow,
which are not present over a long enough time window to have the algorithm adapt and remove it.
Automatic Gain Control Questions
How does the AGC work?
The Vortex’s AGC operates by looking at the input signal and making a determination as to whether the signal is a valid
speech input or not. It does this by analyzing the signal looking for the speech-like components. Once it finds valid
speech (and it is always looking for valid speech), it will estimate the nominal level of the incoming signal. The AGC will
then determine what level to apply to the signal to get it to a 0dBu nominal level. If the signal is too loud then it will
bring it down. If the signal is too quiet, then it will bring it up. If the signal is so quiet that the automixer would not gate
the microphone on, then the AGC leaves the signal alone.
How is the Vortex’s AGC different from other AGC’s?
The Vortex’s AGC algorithm uses a neural network to help make decisions about what is speech and what is not speech.
A neural network is an artificial intelligence concept that is a form of nonlinear adaptive filter with a built-in state
machine. The neural net helps make a much better judgment on whether the input data is speech-like every couple of
hundred milliseconds. Other AGC algorithms may simply use the envelope of the signal to determine if the signal should
be increased or decreased. This has the unintended consequence of training on background noise and making the signal
too loud if there is prolonged silence.
How do we know when something is speech?
The Vortex AGC works in conjunction with the information available from the acoustic echo canceller, the noise
canceller, and the automatic microphone mixer. The acoustic echo canceller determines which side of a conversation is
talking: the remote side, the local side, both sides, or no one. This can help the AGC determine whether it should be
adapting or not. The noise canceller, together with the neural network, determines whether a signal is speech or noise.
If these systems determine that the input is noise, the AGC will not try to adjust the level of the signal. If the automixer
does not gate on for a particular channel, then the AGC will leave that alone because it will treat the signal as a side
conversation that does not need to be increased in level and heard by the remote participants.
When will the AGC not work?
The AGC will not change the level of the incoming signal if the signal was not strong enough to gate on a microphone or
the automixer is configured so that the microphone cannot gate on – for example the priority of that microphone is too
low and this microphone gating on would exceed the maximum number of open microphones that can be open for this
mixer, or chairman mode is on and this microphone is not the chairman. If a conference participant mutes his/her
microphone, the AGC will not turn up his/her speech in an adjacent microphone.
Can I control the parameters?
Conference Composer will allow the user to change the maximum amount of gain that can be applied to the input signal.
Currently the factory defaults are to apply no more than 15dB of input gain and as much as 15dB of attenuation.
How fast does the Vortex’s AGC work?
The AGC is able to bring signals up in level at a rate of up to 5dB per second and down in level at a rate of up to 25dB per
second. This rate is adjustable if you want to limit the speed of the AGC from 1dB per second up to 5dB per second.

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Should I leave the AGC on all the time?
Yes. We have done extensive testing of the AGC and it can dramatically improve the quality of an audio conference. We
recognize that your experience from other AGC’s may not be that favorable, but we definitely suggest you leave the
Vortex’s AGC on all the time because it is very robust. When InstantDesigner creates the design, it will enable the input
AGC will configure it with a +/- 3 dB gain range by default.
Automixer Questions
What style is the Vortex’s automixer?
The automixer (or more accurately, both automixers) in the Vortex use a gating style of automixing. The automixers make
a determination of which signals should be gated on and this decision gets translated into a decision of what gain to
apply to the input signal as it gets mixed with other signals to create an output signal in the matrix. The automixer takes
in up to 8 microphone/line inputs and produces 8 line output signals and gain information to be applied to each of these 8
gated outputs as they are used in the matrix. The matrix does the actual mixing of the signals, but the automixer
determines the gains for the signals. If you select the gated version of an input at a cross point in the matrix then you
will get the signal scaled by the gain that the automixer has determined should be applied to that signal.
What parameters can you control?
There are a number of parameters to control and they are categorized as global parameters, mixer parameters (remember
there are two automixers), and channel parameters. The global parameters are hold time, decay time. The mixer
parameters are maximum number of open microphones, last mic mode, chairman microphone mode, and the amount of
off attenuation. The channel parameters are which mixer the input is assigned to, the gate ratio, adaptive or fixed
threshold, manual threshold, and the gate priority. Details of these options are given in Section 9: Automatic Microphone
Mixing.
What is different about it?
The noise canceller helps remove noise so the gating decisions can be made more intelligently. The speech detector in
the noise canceller also helps to determine whether the channel should gate on.
What about NOM attenuation, can I use it over 8 units?
NOM stands for the number of open microphones and NOM attenuation means the attenuation applied to a sum of
microphone signals to compensate for having some number of open microphones. With the Vortex, NOM attenuation
can be applied to each output signal that is made up of sums of the input microphones. For instance if an output contains
microphones 1-8 which have been automixed and 3 of these microphones are currently open, then an attenuation of
77.4)3(log10 10 =dBcan automatically be applied to the sum of these microphones before they are summed with
the other signals that make up that output.
Now, if you have multiple Vortexes, information about the number of open microphones can be sent to other devices by
using the W, X, Y or Z busses. This means that an output signal made up of microphone signals from linked devices will
have the appropriate NOM attenuation applied to the output signal: )(
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log10 NOM where NOM is the number of
open microphones from all the linked devices being summed together to form that output. So yes, NOM attenuation can
be applied across all 64 available microphone channels.

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Matrix Questions
Why does a 12-input/12-output device have a 27x18 matrix?
There are 12 physical analog inputs into the Vortex EF2280 and there are an additional 14 digital inputs that can come
from the high speed digital EF Bus. Finally the signal generator (white noise, pink noise, or sinusoids) can be mixed into
any output. This accounts for the 27 inputs to the matrix. On the output side there are 12 physical analog line level
output signals, 4 digital bus signals (W, X, Y, and Z), and 2 echo cancellation reference signals that are used internally for
the acoustic echo cancellers. This accounts for the 18 outputs from the matrix.
Why cross point gains?
We wanted the Vortex to be as flexible as possible and felt that a simple router instead of a matrix was too limiting.
Cross point gains allow you to map any input to any output with arbitrary gain. An input can be used in many different
outputs with different gains each time the signal is used.
What can I do with them?
With arbitrary cross point gains you can do much more interesting conferencing with sound reinforcement designs. Also,
as we’ll see with the sub-matrix, the cross points in the sub-matrix allow you to very easily share resources such as
codecs and other signals across all linked Vortexes.
Why is that different?
Previous products gave you no choice in how inputs were mapped to outputs. You took the full strength audio or possibly
mapped full strength inputs into a sub bus and then you could use the sub bus. That technique forced you to think
differently – why not just map the inputs to the outputs with whatever gain you want? This is what the Vortex allows
you to do.
Can I use all inputs and outputs?
Yes. All microphone/line inputs, the A, B, C, and D inputs, the gated microphone 1-8 signals, the 14 bus signals and the
signal generator can be used as inputs. Any of these signals can be mapped to any output with an arbitrary cross point
gain. The exception to this is that the expansion bus inputs cannot be mapped to the same expansion bus output, i.e.,
the X bus input cannot be mapped to the X bus output.
How do I change a matrix cross point?
The easiest way is to use the Conference Composer software and left click on the matrix cell you would like to change.
To do this manually with an RS-232 command, you would simply use the MGAIN command with the row and column of
the cross point you would like to change and then specify the value. Assuming a Vortex EF2280 has a device ID of 0, the
following command sets the cross point of input 5 to output A to –6dB: F00MGAIN5,A,-6. That’s all there is to setting
cross point gain values. You can increment (or decrement) the cross point gain with the MGAIN command too.
F00MGAIN5,A,>3 increments the cross point gain by 3dB. (<3 decrements the gain by 3dB).
Processing Questions
What processing is available?
The processing in the Vortex includes the NOM attenuation on all 12 outputs, the acoustic echo cancellation, the noise
cancellation, automatic gain control, 5 parametric filters for each of the inputs and outpus, and adjustable delay on the
output channels. The parametric filters include highpass, lowpass, notch/boost, high shelf, low shelf filters, and
Linkwitz-Riley lowpass and highpass.

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How do I access it?
The processing is most easily accessed via RS-232 commands. Conference Composer simplifies the process of enabling
the processing and configuring the necessary parameters. The user can also design the filters by setting the appropriate
frequencies, bandwidths, and attenuation/gain values.
Where can I apply it?
The input equalization can be used to compensate for varying characteristics of microphones or input room conditions.
The AGC can help compensate for loud or soft talkers. The noise cancellation can help remove background noise.
What is a parametric EQ? Why would I use it? How do I use it?
Parametric equalization is a technique for applying filters where you need them with arbitrary gains and center
frequencies. This differs from graphic equalizers where the filters have fixed bandwidth and center frequencies. You
might use this to compensate for different microphone frequency characteristics, to compensate for some background
noise such as a 60Hz hum, or to remove some of the room effects.
When would I use a high/low pass filter? How does it work?
You might use a highpass filter to remove some low frequencies such as some boominess in a room. A lowpass filter
could be used to remove high frequency background noise (as well as any desired signal in the same frequency band).
When using InstantDesigner, a 80 Hz highpass filter will be enabled on each microphone input signal to reduce the room
boominess.
Bussing Questions
The EF Bus is used to send high-speed data and control between Vortexes devices.
How does the bussing work?
Within the EF bus there are five busses: the P, W, X, Y, and Z busses. Each of these busses contains up to 8 signals (one
from each linked Vortex). Each Vortex can place an output signal on each of the P, W, X, Y, and Z busses. The P bus
output is only found on the telephony devices and is typically used to transmit the phone signal (‘P’ for phone) between
devices. Since there can be 8 Vortexes linked, this means there are a total of 32 signals on the EF bus at any given time
and each linked Vortex can get any of these signals off the bus. With the addition of the P bus on the telephony
products, up to 8 EF2280’s and 8 EF2201’s can be linked together for a total of 16 devices. The W, X, Y, and Z busses
include NOM information and are most often used to link microphones between devices, but can also be used to share
line level sources between devices.
What is the sub-matrix? And how many are there?
The sub-matrix is a smaller matrix that feeds the main matrix. The inputs to the sub-matrix are the bus signals from all
the other devices that are linked. In the Vortex there are five sub-matrices, one for each of the P, W, X, Y, and Z busses.
Each sub-matrix has 7 inputs (the maximum number of devices that can be linked to any given device). Since a device’s
bus cannot be linked to itself, there are only 7 inputs, not 8 to each sub-matrix. In the Vortex, each sub-matrix for the W,
X, Y, and Z busses has 3 outputs and the sub-matrix for the P bus has 2 outputs, which become inputs to the main matrix.
Any of the three outputs from each sub-matrix can have arbitrary cross points applied to them so you can weight the
signals from other devices to enable arbitrary zoning or mute some of them to extract just the signals from the bus that
you want.

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If you are more comfortable using the bus as a simple mix-minus of all the other bus signals on the particular bus (W, X,
Y, or Z) then any of the three outputs from each sub-matrix (one for W, X, Y, and Z) can be configured as a mix-minus of
the other linked device’s entire W, X, Y, and Z expansion bus signals, respectively.
Why is it different from the main matrix?
The five sub-matrices make the main matrix more manageable. Essentially the bus signals from other devices are mixed
down to 12 main matrix inputs in the sub-matrix. Each of the 14 outputs from the sub-matrix (3 for each of the W, X, Y, Z
busses and 2 for the P bus) can have arbitrary cross point gains or mutes before combining the channels for presentation
to the main matrix.
How many channels can I use?
Each Vortex can map its inputs to the P, W, X, Y, and Z expansion busses just like it would create any other matrix output
signal. These five outputs are available to all the other linked devices as inputs to the sub-matrix.
How do I access them?
If you want to use the linked signals individually or with different gains, you should access the signals from the sub-
matrix. If just want a mix-minus of all the other devices, you can configure any of the sub-matrix outputs to be the sum
of all the other devices excluding the local device.
Can I share codecs and program audio sources easily through the busses?
Yes. Any input to a Vortex can be shared with other linked Vortexes by putting the signal on the expansion bus and then
any other Vortex can get that signal off the bus by muting all the other sub-matrix cross points except the one that it
wants.
How far can the bussing be run?
Because the bus is very high speed, it is required to keep the length of each cable segment to less than 14 ft (4 m).
RS-232 Control Questions
Will RS-232 work with AMX and Crestron?
Yes. Absolutely. Polycom has provided all the programming information to AMX & Crestron and macros are available.
What can I control via RS-232?
Absolutely everything. Every feature in the Vortex has an RS-232 command and documentation as to how to control the
feature. The Vortex has a very readable and friendly command set. Section 12 lists the Vortex RS-232 commands.
How does the Vortex work across multiple Vortex devices?
A linked network of Vortexes uses a single serial port on the host PC or controller. The remaining Vortexes receive their
commands via the EF Bus. This way only one Vortex needs to be connected to the control system and the remaining
Vortexes are linked in a daisy chain fashion. However, if you would like to connect multiple controllers to multiple linked
Vortexes, you can do that too. Each Vortex can be connected to its own controller (although in most applications you
would only need one controller to control all the linked devices). See the application note Interfacing to Multiple Vortex
Devices via Multiple RS-232 ports for more information.
Does the Vortex give mixer gating information to the controller? How?
Yes. With a single RS-232 command (GATEEN1 for GATE ENable On or CGATEEN1 for Camera GATE Enable On), the
Vortex will send event-driven gating status commands to the main controller. As the gating status of microphones
change, the Vortex will automatically send out a status message. Another command can be used to turn off this flow of
information. Gating information can also be mapped to the logic outputs, but it is usually simpler to have the Vortex

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continuously sending the data via RS-232 to the control system (no polling is necessary). The Camera gating feature
allows you to setup an amount of time (up to 5 seconds) that the microphone must be gated on before a camera gating
indicator will be sent. This information can be used for camera positioning.
What about IP addressing?
Polycom has an IP accessory, the Vortex Ethernet Interface, that can be used to configure the Vortex devices remotely.
Logic Control Questions
How do you address logic pins? How many controls can you have?
The product has 24 logic input pins and 20 logic output status pins. The logic pins are most easily accessible through the
Conference Composer software. Logic input pins can be programmed to execute a preset, a macro, or an individual
command on either closure, opening, or held open/closed.
What about volume control?
Volume control can be done either by mapping a single level increment command to the logic pin, or multiple levels (like
a stereo volume) can be changed by creating a macro and assigning the macro to a logic input pin. The product supports
output gain control, input gain control, and matrix cross point control with simple RS-232 commands.
Is it re-configurable?
Absolutely. You can change pin assignments and functions very easily.
What are macros? Why would I need them?
Macros are a collection of up to 256 Vortex commands that can be executed with a single RS-232 command or contact
closure. You might use macros to ramp stereo volume, customize a preset, do sound masking, send commands to a video
codec for camera positioning, or anything else you can think of.
Can I combine multiple logic pins into a group to handle room combining applications?
Yes. The product supports 4 groups of pins where each group can have up to 5 logic pins assigned (32 combinations).
The groups can be used in room combining applications to select different presets or macros to execute based on the
combinations of input pins.
Can I get gating information from groups of mics on a single logic output pin?
Yes. You can assign the gating status of a single input or groups of inputs to a single logic pin. When assigning a group
of inputs (such as microphones 1, 2, and 6), you can choose whether you want the logic output status to be TRUE if ALL
microphones are gating (1 and 2 and 6 in this example), or if ANY of the microphones are gating (1 or 2 or 6 in this
example), or if ALL microphones are NOT gating or if ANY of the microphones are NOT gating. The syntax for the
command to assign status information to output pins is very easy to understand.
How can I configure the Vortex to automatically “duck” outputs based on microphone gating activity?
You can easily setup a macro to duck particular outputs based on gating activity of a collection of microphones. By
connecting a logic output pin (configured to show gating information for the particular microphones of interest) to a logic
input (tied to the ducking macro), you can duck outputs every time the collection of microphones gates on and “un-duck”
when the inputs gate off.

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Preset Questions
How many presets are in the Vortex?
There are 16 factory presets and 32 user presets for a total of 48 presets. The presets store all the information in the
device including input gains, matrix cross points. Also, each device stores a complete set of text labels of inputs,
outputs, macros, presets, and logic pins.
How do the factory presets work? How are they set up?
The factory presets are stored in an area within the Vortex where they cannot be overwritten by a user. They are
provided to make it easy to get started using the Vortex. The factory presets are common setups that may be sufficient
for many different applications. The factory presets can be used as the basis for user presets, and then modified and
saved.
Does the Vortex come up as a "blank slate"?
The Vortex as shipped from the factory comes up in the default configuration of preset 0 and the power on preset is set
to 0. The Vortex can be configured to power up with any of the factory or user presets and will not come up blank unless
you save a blank preset and have it power up to that preset.
How do I select which preset the device powers up into?
On the presets page within Conference Composer you can select which preset to use when powering up. This can also
be set from the LCD and with RS-232 commands. The default from the factory is to power up into factory preset 0.
What if I make changes? Will the preset still be there?
Presets are stored in non-volatile memory. Once loaded into the Vortex, changes can be made to the settings of the
Vortex. However, unless the changes are saved as a preset (either a new preset or overwriting the existing preset), the
old preset values will be used the next time the device is powered up or reset. The changes are not saved to the non-
volatile memory unless you tell the settings to be saved.
Can I password protect presets?
Yes. There is an optional write-protect password (in addition to the front panel lock out password) that can be used to
prevent users from overwriting presets within the Vortex. When the Vortex is write-protected, the user can change
which preset is running in the device, but cannot save a new preset and cannot change the preset selected upon power-
up.
Software Questions
What type of computer do I need?
The minimum computer configuration for running Conference Composer is a 500 MHz Pentium computer with 128MB of
memory and 50MB of free disk space. The recommended system is a 700MHz or better Pentium with 256MB of memory
and 50MB of available disk space. Windows 2000 or Windows XP is recommended.
Can I work offline?
Yes. With Conference Composer you can work offline, design the system, and save files to disk. You can easily restore
files and upload information into a product when you decide to go online.
What do I need do do to set up my Vortex unit for operation?
In many cases, you don’t need to do anything – a Vortex preset will work fine for your application. If you are dealing with
multiple microphones, different types of microphones, multiple loudspeakers and other equipment, we recommend that
you use the InstantDesigner software wizard. When you first open Conference Composer, you will be given the choice to

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create a project with InstantDesigner. This easy-to-use tool takes you through a set of pull-down menus in which you
select the number and types of microphones, amplifiers, and other equipment; InstantDesigner then automatically
generates a Conference Composer system file. It will determine your matrix settings, gain structures, etc. If you need to
further adjust settings, our Conference Composer software will allow you to change anything in your system
configuration.
What parameters can I have access to in Conference Composer?
Conference Composer makes every parameter in the Vortex accessible. Conference Composer is organized into tabs
where each tab shows the controls for that particular function. There are tabs for the device inputs, the device outputs,
the automixer, matrixer, the logic inputs and outputs, presets, macros, room diagnostics, system, and the global settings
of the device.
What about the labels? How do they work?
Text labels can be entered for all the input and output signals, the logic pin names, and macro and preset names. Each of
these labels are stored within the Vortex and can be up to 16 characters in length.
What are the different levels on the left side of the Conference Composer software?
Conference Composer organizes your projects into a hierarchy of Workspace, Project, Device Chain, and Device. Starting
from the bottom of the list, a device is simply that – some piece of equipment that will be used in the installation. A
Device Chain is a collection of devices that are linked together through the EF Bus (that’s where the name device chain
comes from). Typically these represent all the devices that are tied to a particular serial port on your
computer/controller. The project represents a collection of device chains while the workspace allows you to store a
collection of projects. You can keep multiple independent projects in your workspace. You can think of the workspace as
your hard drive, the projects as directories, the device chains as files and the devices as items in the files.
Will Conference Composer automatically get information from a Vortex?
You can choose to synchronize to a connected Vortex or collection of Vortex devices. This will cause Conference
Composer to go out and have all the products send their information to the PC. As you change values on the PC, the
corresponding changes take place in real-time on the connected devices.
Can I print my saved information?
Yes. There is a way to create a report from the configurations on your devices. Conference Composer makes it easy to
print reports.
Can I copy information in the software? To another Vortex?
Yes. You can copy information from one device to another device in the Conference Composer Navigator panel by simply
clicking and dragging the device into a second device or dragging any of the settings such as matrix settings or macro
settings from one device to another.
General Questions
Can the Vortex be used with ceiling microphones?
Yes. The combination of the Vortex’s noise cancellation (to reduce the amount of noise picked up by the microphones),
the acoustic echo cancellation (the ability to handle positive room gain), and the AGC (to increase the signal level) allows
you to use ceiling microphones and loudspeakers and have your audio conferencing system work well. While we can’t
break the laws of physics, we can at least make ceiling microphones work the way you would like them too.

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How do I keep someone from messing up the system?
There are two levels of passwords with the Vortex. The first is front panel lockout. If you enable the front panel lockout
then your users will be able to view the settings but not change any values from the front panel. The second level of
security is the write-protect password (also referred to as the non-volatile memory lock). If the Vortex is write-protected,
users will be able to change settings and change which preset is currently loaded, but they will not be able to overwrite
presets, or macros, and will not be able to change which preset the Vortex powers up into.
Can multiple Vortex products be linked?
Yes, you can link up to eight Vortex devices in any combination with one exception. If you are using multiple Vortex
EF2201 telephone hybrids, up to eight of them can be linked to up to eight Vortex EF2280 units. The reason is that the
Vortex EF2280 and Vortex EF2201 can share the same device ID number.

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6
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While the Vortex performs a large variety of complex tasks, the control and implementation of these tasks is very simple to the
user. The simplicity comes from the Conference Composer Windows™ software and the elegant design of the Vortex hardware.
The power of the digital signal processors has allowed our engineers to design an echo canceller that has full bandwidth – not
limited to only 7kHz or even 15kHz. With the Vortex, conferencing can now sound as good as the face-to-face experience. By
designing the system this way, all the program audio and other sound reinforcement audio will have 22kHz audio bandwidth. This
opens up the possibility of full bandwidth audio conferencing over broadband connections.
In its simplest form, the Vortex is an automatic microphone mixer with full cross point matrix. All the microphone parameters can
be customized and any input can be mapped to any output with an arbitrary gain applied to the cross point. Adjustments in levels,
matrix cross points, and other functions can be made in one of three ways: RS-232 control via the Conference Composer software
or a dedicated control system, the logic input pins, and the front panel buttons and LCD.
In reality, the product is much more than an automatic microphone mixer, it includes automatic gain control for automatically
leveling the microphone input signals, noise cancellation for reducing the amount of ambient noise picked up by the microphones,
acoustic echo cancellation for removing the echo of the remote talkers voice from being sent back to them, and many other
features that are detailed in the block diagram in Figure 2 and Figure 4.
Figure 2. Block diagram of the Vortex.

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Each of the 8 mic/line inputs has the EN processing block that is shown in Figure 3. The balanced input signal passes through a
digitally controlled, analog gain stage, is converted to a digital signal and then processed by the acoustic echo canceller, the noise
canceller, the automatic gain control, the parametric equalizer, and then the automatic mixer. The details of the processing are
described in the next section.
Vortex Front and Rear Panels
Figure 6 shows the front and rear panels of the Vortex along with numeric pointers for understanding what the different connectors
are. Rack ears are built into the Vortex enclosure design.
The features of the Vortex are described below:
1. LCD Display. Displays menu instructions for configuration and operation of the Vortex.
Echo
Canceller Noise Canceller
EC1, EC2, Bus
EN (Echo Canceller, Noise Canceller)
PEQ GateMute Gated
Ungated
AGC
Parameters On OffOn OffOn Off Parameters
Figure 4. The channel processors for each of the 1-8 mic/line inputs.
134 5 72 86
Figure 6. The product front and rear panels.