KLIPPEL KCS-ID User manual

R&D SYSTEM USER’S GUIDE
KCS-ID Manual
K l i p p e l G m b H
July 23, 2021
Copyright © 2000-2021 Klippel GmbH
Mendelssohnallee 30, 01309 Dresden, Germany
www.klippel.de

Klippel R&D System Contents
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I
Contents
1KCS-ID Manual....................................................................................................... 1
1.1 Introduction........................................................................................................................ 1
1.2 System Requirements......................................................................................................... 1
1.3 Hardware Setup.................................................................................................................. 2
1.3.1 Hardware Connection ............................................................................................... 2
1.3.2 Hardware Setup - Routing......................................................................................... 2
1.4 Performing Measurements ................................................................................................ 3
1.4.1 Basic Measurement Setup ........................................................................................ 3
1.4.2 Additional Options .................................................................................................... 4
1.4.3 Limit Parameters....................................................................................................... 4
1.4.4 Running and Interpreting Measurements................................................................. 5
1.5 Creating Initial Data............................................................................................................ 7
1.6 Xmax and Xtarget ..................................................................................................................... 7
1.6.1 Why is Xmax not equal to Xtarget?................................................................................. 7
1.6.2 How to achieve a higher Xmax?................................................................................ 8
1.7 Transducers with multiple voice coils ................................................................................ 9
1.8 Troubleshooting ............................................................................................................... 10
1.8.1 KCS-ID messages ..................................................................................................... 10
1.8.2 KCS Server messages............................................................................................... 10
2Index ................................................................................................................... 13

Klippel R&D System KCS-ID Manual
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1KCS-ID Manual
1.1 Introduction
The KCS-ID Parameter Identification is a measurement module which is required for creating initial
speaker parameters for the KLIPPEL Controlled Sound Technology (KCS).KCS-ID uses a multi-tone
stimulus to excite a loudspeaker and measures electrical voltage, current and optionally laser and
microphone signals. After the measurement, the signals recorded by KCS-ID are sent to the KCS
Server which automatically creates initial KCS data comprising linear and nonlinear speaker
parameters for the particular KCS hardware platform. This initial data set is stored in a KCS Monitor
operation and can be downloaded from the server. The KCS Monitor operation can connect to any
supported KCS hardware platform and a KCS control session can be started.
This manual gives step-by-step instructions on how to create the initial data:
1. Hardware Setup
2. Performing a measurement
3. Creating initial data
Initial Identification
KCS-ID
Initial Parameter
Creation
Lab KCS Server
KCS Evaluation
KCS Monitor
Zip file
KCS Monitor
operation
1.2 System Requirements
The following hardware is required for running KCS-ID:
KLIPPEL Analyzer 3 (KA3)
Power amplifier or KLIPPEL AMP Card
It is highly recommended to use
Microphone
Triangulation Laser
The following software is required for running KCS-ID:
An installation of KLIPPEL dB-Lab of version >= 212.30

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KCS-ID license
Internet access is required for creating initial parameters on the KCS Server.
1.3 Hardware Setup
1.3.1 Hardware Connection
The hardware setups on the KLIPPEL KA3 comprising one Speaker Card, one Laser CARD, one XLR
Card and an optional AMP Card is illustrated in the figures underneath. For more information about
the hardware, please see Manual Hardware.
Laser and microphone sensors are not necessarily required for operating KCS-ID and KCS Monitor.
However, these sensors are highly recommended for determining the voice coil’s peak displacement
automatically and for getting a comprehensive set of diagnostics information.
The microphone should be placed in the near-field of the device under test to achieve a high signal-
to-noise ratio. A microphone calibration is not necessary as a relative measurement comprises all
relevant information required by KCS-ID. Make sure that IEPE/phantom power is switched on using
the buttons next to the microphone input on the KA3’s front panel.
If a transducer with multiple voice coils shall be used, please see section 1.6.
DUT
Klippel KA3
Laser
Microphone
Amplifier
Input Output
DUT
Klippel KA3
Laser
Microphone
Hardware connection on KA3 with AMP Card Hardware connection on KA3 without AMP Card
Attention: Keep the polarity consistent. It is crucial that the speaker is connected with the same
polarity to the KA3 as later on the KCS target hardware platform.
1.3.2 Hardware Setup - Routing
In the dB-Lab software’s tool bar, open Extras KA3 KA3 Signal Configuration to setup the
routing. Set the correct output channel (AMP if an AMP card is used or XLR if an external amplifier is
used) and input channels for the optional external sensors.
If not done already, calibrate your laser using the LC KA Laser Calibration module accessible in the
dB-Lab’s tool bar Extras KA3Laser Calibration (more information in Hardware Manual
[Hardware]).

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Note: The current sense (Low/High Sense) is set automatically by the KCS-ID operation and does not
have to be changed for the KCS-ID measurement.
KA3 Signal Configuration
1.4 Performing Measurements
1.4.1 Basic Measurement Setup
Open a database by pressing Select Database in the dB-Lab software. Create a new KCS-ID
operation, open its Properties by right-clicking on the operation and set up the measurement as
follows. It is assumed that the hardware is set up as described in the previous section and laser
sensor and microphone are connected to the KA3.
1. Select the Speaker System Type (free air, sealed box or vented box/passive radiator) and the
Target Bandwidth (fullrange, woofer/midrange or subwoofer).
Note: The KCS-ID measurement has to be performed in an enclosure of similar specification (same
volume and same passive radiator/port properties) like used in the KCS on-line mode.
2. Select Limit Parameters. It is recommended to never switch off the Impulsive Distortion
limit which indicates excessive impulsive distortion (Rub&Buzz). If the target displacement
Xtarget is known, it should be specified here as limit parameter. See the next section for more
detailed information about the limit parameters.
3. Select the hardware platform the initial data shall be created for. Only KA3:Also, the Target
amplifier (AMP card or External amp) has to be specified. If External amp is selected, the
same amplifier with the same gain settings on which the KCS-ID measurement is performed
has to be used as amplifier for running KCS.
This step can also be done after the measurement.
Note (KA3 target platform only): It is highly recommended to use the AMP card for KCS evaluation if
its voltage and power capabilities are sufficient for the particular speaker, because DC coupling is not
supported on external amplifiers. The AMP card can provide a peak voltage of approx. 20 V and can
handle a minimum load of 2 Ω(see specification [H6 Amplifier Card])

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Note: Bl(0) can only be imported if no laser is used (switch off Laser Connected in the Peripherals
category). If a laser is used (which is highly recommended), Bl(0) is identified accurately on the KCS
Server.
1.4.2 Additional Options
Stimulus
The Stimulus settings are set to Automatic by default. You can select a higher Start Voltage if you
use a big speaker and want to accelerate the ENLARGEMENT MODE. In some cases, the Level might
be set to Manual to fine-tune Xmax (see 1.6.2).
Peripherals
Select whether laser/microphone sensors are used in this measurement. It is recommended to use
both, however sometimes the laser might not have access to the transducer’s membrane and
cannot be used. Note that a microphone calibration is not required for this measurement.
Advanced
Save Intermediate Results saves the results of each measurement block into a new KCS Monitor
operation. It is not recommended to activate this option. However, KLIPPEL support might require
this data in case of problems.
1.4.3 Limit Parameters
In the ENLARGEMENT MODE, the excitation voltage is incrementally increased until the first limit
parameter is reached or exceeded. Following limit parameters are available:
1. X target - Maximum absolute peak voice coil excursion that shall be used in the target
application. If a laser is used, the peak displacement value is measured by a laser sensor. If
no laser is used, it is calculated by a linear speaker model and a Bl(X=0) import which e.g. can
Property page of KCS-ID module

Klippel R&D System KCS-ID Manual
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be taken from the driver’s datasheet. Note that in this case, the displacement value can
differ significantly from the real voice coil excursion as it depends on a manual Bl(X=0)
import and only uses a linear speaker model. See 1.6 for further information about Xtarget and
Xmax
2. Impulsive Distortion - Impulsive distortion is identified by exploiting out-of-band distortion
in the sound pressure signal. Two parameters indicating excessive impulsive
distortion/Rub&Buzz issues are used: The IDRMT (Impulsive Distortion Ratio according to IEC
60268-21 for multi-tone stimuli) limit is the ratio between peak higher order distortion and
mean SPL. To be sensitive to very audible short impulsive distortion peaks with low energy
(such as beating wires), the crest factor CIDMT of the out-of-band distortion is calculated.
High IDRMT or CIDMT values indicate that the speaker is working above its safe working range.
The impulsive distortion metrics IDRMT and CIDMT are calculated similarly like the IDR or CID
values for sinusoidal excitation (see TRF Transfer Function module). However, the crest
factor of the multi-tone is much higher than that of the sinusoidal tone, which is one reason
why the multi-tone impulsive distortion limits are much lower than their counterparts for
sinusoidal excitation. It is not recommended to change the default impulsive distortion
limits.
Note: The IDR is very susceptible for impulsive distortion (e.g. voice coil rubbing) and not so much
for air flow noises which exhibit less impulsive characteristics.
Coil Temperature –Maximum allowed relative voice coil temperature increase. If this limit is
exceeded, the measurement is immediately stopped. The measurement of the coil
temperature is done by measuring its DC resistance The reference temperature is measured
in the LINEAR MODE.
Note: Voice coils do not heat up homogenously. Usually, the hottest place is at the rims, while it is
colder in the gap. KCS-ID measures the average temperature, hence allow some margin to the
maximum absolute maximum temperature rating of the voice coil.
1.4.4 Running and Interpreting Measurements
Press the Run button to perform a measurement.
Now multiple measurement steps are performed consecutively:
1. LINEAR MODE: Small signal parameters are identified and optimum settings for the
NONLINEAR MODE are determined.
2. ENLARGEMENT MODE: The excitation level is incrementally increased to approach the voice
coil’s peak displacement xmax. This mode is finished when any of the limit parameters are
reached.
3. NONLINEAR MODE: This measurement excites the speaker so that the peak voice coil
displacement corresponds approximately to its working range xmax in the final application.
4. THERMAL MODE: If the voice coil heating was not sufficient in the NONLINEAR MODE,
another measurement of the voice coil heating characteristic is performed before measuring
the cooling curve.

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Attention: Always wear ear protection since very high sound pressure levels may occur during the
measurements.
Overview of default windows of finished KCS-ID operation
If the measurement has successfully finished, the measurement status overview in the State table
displays a PASS after all measurement modes and an 8-character identification number. Initial KCS
data can now be created based on this measurement. If the measurement has not finished
successfully, check the Speaker Parameters window for any warning messages and follow its
instructions.
State Window of successfully finished KCS-ID operation

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1.5 Creating Initial Data
Property Page of KCS-ID operation –Export for Initial Data Creation
The KCS-ID measurement data has to be sent to the KCS Server so that initial data can be created for
your specific hardware platform. Save the zip file on your hard drive. Now press Open KCS Server
which opens KCS Server website www.klippel-hub.de.
After logging-in, the zip file can be uploaded. Based on this data, the KCS Server creates a full initial
data set for operating KCS comprising linear and nonlinear speaker parameters, calibration values
and more. After the processing is finished, a KCS Monitor operation is created and can be
downloaded.
Now you are ready to start KCS on-line processing. See the Manual KCS Monitor [KCS3]. Before
evaluating KCS it is highly recommended to see Tutorial 4 (Alignment, Equalization) and 5
(Protection, Limiter) of [KCS3] which describe steps how to achieve best audio performance.
Note: The hardware platform can be selected after the KCS-ID measurement has finished. If initial
data for different target platforms shall be created, it is not necessary to perform another KCS-ID
measurement.
KCS Server –Uploading Data and List of File Exchanges
Note: Request a KCS-Server account by sending an email to [e-mail]. Note that this
login is not connected to the Download Manager log-in on www.klippel.de/dm.
1.6 Xmax and Xtarget
1.6.1 Why is Xmax not equal to Xtarget?
A maximum voice coil displacement Xmax is automatically detected in the KCS-ID and on the KCS
Server. Xmax is the voice coil excursion which shall never be exceeded during KCS on-line operation.
The determination of Xmax is based on the KCS-ID limit parameters
Xtarget

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Impulsive distortion
If one of these limits is reached in the ENLARGEMENT MODE, the corresponding voltage is used to
perform the NONLINEAR MODE measurement which is the basis for nonlinear parameter
identification.
It can happen that the resulting Xmax which the KCS Server determines is lower than the Xtarget, even if
it was reached in the KCS-ID measurement. This can have multiple reasons:
No Laser in KCS-ID
If no laser is used in in the KCS-ID measurement, the peak excursion is estimated based on a
linear speaker model using a manual Bl(0) import. However, a linear model cannot describe
a real speaker with good accuracy. Based on the degree of nonlinearity of the speaker, the
peak excursion estimation can be quite significantly lower than in reality. Hence when the
speaker’s nonlinear parameters are identified on the KCS Server, the resulting excursion
might be lower than the estimated one of the KCS-ID.
Asymmetric Voice Coil Excursion
Electrodynamic transducers are nonlinear systems. Based on the particular design, some
nonlinearities might exhibit a significant asymmetry which can cause an asymmetric peak
excursion. This means that for instance the positive peak displacement is higher than the
absolute peak value on the negative side (see curves below).
If the voice coil is never reaching a certain excursion range during the KCS-ID measurement,
the parameter identification system running on the KCS Server cannot identify the speaker
parameters in this range reliably. In addition it is not known whether impulsive distortion
occurs if the voice coil would be driven to this excursion range during KCS on-line operation
with other signals.
Hence the KCS Server determines a safe and conservative Xmax value, whereas the peak
excursion displayed in the KCS-ID is an absolute peak value.
Nonlinear Parameters can cause asymmetric peak excursion in the KCS-ID measurement
Significant Voice Coil Heating during KCS-ID
If the voice coil heated up significantly during the NONLINEAR MODE, excursion can
decrease during the measurement due to an increasing voice coil resistance. Hence the peak
excursion was overestimated in the shorter ENLARGEMENT MODE measurement.
1.6.2 How to achieve a higher Xmax?
If you are sure that the transducer can handle a higher Xmax than the KCS Server determined, you can
repeat the KCS-ID measurement with higher excitation voltage. The easiest way to do that is

Klippel R&D System KCS-ID Manual
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1. Open the KCS-ID operation which lead to an insufficient Xmax and copy the operation.
2. In the KCS-ID Properties (category Stimulus), change the Level from Automatic to Manual
3. Increase the level depending on how much you want to increase the Xmax compared to the
previous measurement.
4. Repeat the measurement and create initial data with higher Xmax using the KCS Server again.
1.7 Transducers with multiple voice coils
Initial KCS data can also be created for transducers with multiple voice coils, each driven by a
separate amplifier channel.
Note: KCS only supports multi coil configurations if all coils show identical small and large signal
properties. Please contact Klippel if you are unsure if your transducer is suited.
Dual Coil Speaker
KA3
Amplifier
Input Output
Laser
Microphone
1 2
Hardware connection for double voice coil speakers
To create the data, you need to run the KCS-ID operation with the voice coils connected in series as
shown above for a dual voice coil speaker.
Note: Due to the series connection, the peak voltage demands of KCS-ID for the amplifier will rise
according to the number of voice coils. Make sure that your amplifier can deliver the required peak
voltage.

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1.8 Troubleshooting
1.8.1 KCS-ID messages
Amplifier Headroom exceeded
The KA3’s amplifier can provide approx. 19…22 V peak (depending connected DC resistance). The
error message pops up if more voltage is required to reach a certain limit or the excitation voltage is
set manually to a level exceeding the amplifier’s capability. Note that the multi-tone stimulus has a
crest factor of approx. 3. Hence, the maximum possible voltage is 6…7 V RMS when the internal AMP
card is used.
You can use an external amplifier that can provide more voltage to drive the transducer to its limits
or to reach a higher excitation voltage.
If 6…7 V RMS are sufficient because the target amplifier used in the KCS online mode cannot deliver
more voltage anyway, you can set the level manually to approx. 6 V RMS in the KCS-ID’s property
page’s category Stimulus.
High voice coil position change detected
This message indicates that between LINEAR MODE and NONLINEAR MODE either
the voice coil was shifted significantly due to very asymmetric nonlinear behavior of the
transducer or
the distance between laser sensor and transducer membrane position has changed
Note that the rest position of the NONLINEAR MODE is used as reference rest position used in the
KCS on-line mode. The voice coil stabilization feature will shift the voice coil to this reference rest
position.
Check correct Speaker System Type setting
KCS-ID performs a small signal speaker parameter identification in the LINEAR MODE. If it detects
that e.g. the number of distinct impedance magnitude peaks does not correspond to the specified
Speaker System Type (e.g. sealed or vented enclosure), this message appears. Note that in rare
cases, the warning might trigger even if the correct speaker type is set. In this case you do not have
to do anything.
1.8.2 KCS Server messages
The KCS Server website might display warnings and information after a KCS-ID file has been
uploaded. See explanations of selected info and error messages below.
Info/Warning Messages
Low both-sided Bl(x) decay. Detection of the voice coil rest position and stabilization might not
work optimally.

Klippel R&D System KCS-ID Manual
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For identifying the voice coil rest position, KCS evaluates the nonlinear distortion found in the
measured current signal caused by the nonlinear Bl(x) speaker characteristic. If the Bl(x) curve is too
linear, not enough distortion is created to perform an identification of the rest position. In this case
also an active shifting of the voice coil position using a DC voltage (Stabilization) is not possible.
Note that KCS will work anyway, but higher safety margins for the maximum allowed excursion are
required, leading to less acoustical output at low frequencies.
For KCS it is highly recommended to use a speaker with a higher decay of the Bl(x) curve (usually a
decay to 50…75% relative to Bl(x=0). The higher Bl(x) decay leads to higher efficiency and sensitivity
and the added nonlinear distortion caused by the more nonlinear Bl(x) is compensated by KCS. In
addition, the KCS stabilization allows to exploit the working range of the speaker optimally.

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Bl(x) offset > 25%. Use a transducer with centered voice coil offset for maximizing efficiency.
If the voice coil offset is very high compared to the peak displacement (left picture), sensitivity and
efficiency drop. For best performance it is recommended to use a transducer with a centered voice
coil (right picture).
Xmax had to be reduced. It could not be realized on both positive and negative side of the
identified Bl(x) curve.
See 1.6.
Xmax was reduced due to exceeded IDR limit.
Xtarget could not be reached because the impulsive distortion limit (IDR Limit) was hit at excursions
smaller than Xtarget. Either the transducer cannot be used up to the specified peak excursion without
producing excessive distortion or the IDR Limit was set too conservatively.
Laser Position has changed by more than 20% of maximum measured excursion during KCS-ID
measurement.
See 1.8.1 (High voice coil position change detected).
Amplifier Gain is not sufficient to reach desired Xmax. Xmax has been reduced.
The gain of the specified target amplifier is not sufficient to drive the speaker to the Xmax determined
in the KCS-ID. Xmax was reduced.
Error Messages
High Linear Identification error/High Nonlinear Identification error
Speaker parameters could not be identified with sufficient accuracy. Check if the Speaker Type was
set correctly in the KCS-ID. If it was, contact kcs-[email protected].
Bl(x) variation too high. Reduce limits or excitation level.
If Bl(x) decays to a value smaller than 0.25*Bl(x=0) at either positive or negative displacements,
highest accuracy of the nonlinear parameters cannot be ensured under all circumstances. In
addition, a disproportionate high peak voltage is required in KCS on-line mode for linearization.
Reduce limits in the KCS-ID or reduce the voltage manually.
Kms(x) variation too high. Reduce limits or excitation level.
If Cms(x)=1/Kms(x) decays to a value smaller than 0.25*Cms(x=0) at either positive or negative
displacements, highest accuracy of the nonlinear parameters cannot be ensured under all
circumstances. In addition, a disproportionate high peak voltage is required in KCS on-line mode for
linearization. Reduce limits in the KCS-ID or reduce the voltage manually.

Klippel R&D System Index
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2Index
A
Additional Options.......................................................... 4
B
Basic Measurement Setup ..............................................3
C
Creating Initial Data ........................................................7
E
Error Messages .............................................................12
H
Hardware Connection.....................................................2
Hardware Setup..............................................................2
Hardware Setup - Routing ..............................................2
How to achieve a higher Xmax?......................................8
I
Info/Warning Messages................................................10
Introduction....................................................................1
K
KCS Server messages ....................................................10
KCS-ID Manual ................................................................1
KCS-ID messages...........................................................10
L
Limit Parameters.............................................................4
P
Performing Measurements.............................................3
R
Running and Interpreting Measurements ......................5
S
System Requirements.....................................................1
T
Transducers with multiple voice coils.............................9
Troubleshooting............................................................10
W
Why is Xmax not equal to Xtarget?.................................7
X
Xmax and Xtarget............................................................7