KLIPPEL KCS User manual

Klippel GmbH Controlled Sound Goal of this Guide
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KCS SYSTEM USER’S GUIDE
KCS Evaluation Tutorials
July 08, 2021
Copyright © 2000-2019 Klippel GmbH
Mendelssohnallee 30, 01309 Dresden, Germany
[e-mail]
www.klippel.de

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Goal of this Guide Klippel GmbH Controlled Sound
Contents
1Goal of this Guide .................................................................................................. 3
2Requirements ........................................................................................................ 3
3Hardware Setup..................................................................................................... 4
3.1 KCS running on Nuvoton Platform (NAD)........................................................................... 5
3.2 KCS running on Klippel Devices .......................................................................................... 6
4Software Setup ...................................................................................................... 8
5Tutorial 1 –Check Setup....................................................................................... 12
6Tutorial 2 –Measuring the Frequency Response................................................... 13
7Tutorial 3 –Active Speaker Evaluation.................................................................. 14
8Tutorial 4 –Evaluate Mechanical Protection System............................................. 17
9Tutorial 5 –Multi-Tone Distortion........................................................................ 20
10 How to Treat Rub+Buzz Issues.............................................................................. 22

Klippel GmbH Controlled Sound Goal of this Guide
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1Goal of this Guide
This document describes how to evaluate the KLIPPEL Controlled Sound technology (KCS) by using the
KLIPPEL QC measurement framework. The following topics are covered:
•Measuring the frequency response
•Evaluation of the performance of active systems including KCS in the large signal domain
•Evaluation of the KCS speaker protection
•Evaluation of multi-tone distortion compensation
•How to treat Rub&Buzz problems
2Requirements
Its mandatory to read the document Manual KCS Monitor.pdf which teaches necessary KCS
basic knowledge before the KCS evaluation tutorials are executed!
Hardware:
•KCS hardware platform (e.g. Nuvoton Audio Development Board (NAD), Klippel Analyzer 3
(KA3), APE Evaluation Board etc.)
•Measurement Equipment. There are two options:
oKA3 measurement device:
▪Klippel Analyzer 3 (KA3)
▪Microphone
oNAD on-board microphone (DMIC):
▪Klippel Dongle
▪DMIC module mounted on NAD board
Software:
•Klippel dB-Lab of version >= 210.826
•Licenses for: QC Standard 6 for KCS, SPL task, Multi-tone distortion task, SYN, 3DL
•Additional License (only for QC measurement with NAD board DMIC): QC no PA hardware
required (== QC Standalone)
In addition, following Klippel dB-Lab operations are required:
•KCS Monitor operation comprising initial data for the particular DUT
•QC operation template KCS Evaluation Template.kdbx

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Hardware Setup Klippel GmbH Controlled Sound
3Hardware Setup
There are different hardware setups dependent on the device on which KCS is running (KCS device)
and what device is used as input device for the QC measurement (QC measurement device). Details
about specific hardware setups applicable for your particular application are listed in the chapters
below.
KCS device
QC meas-
urement
device
Related hardware setup chapter
Nuvoton Plat-
form (NAD)
Klippel KA3
3.1 KCS running on Nuvoton Platform (NAD)
Hardware Connection using KA3 as QC Input Device
Nuvoton Plat-
form (NAD)
NAD DMIC
(= NAD
onboard mic)
3.1 KCS running on Nuvoton Platform (NAD)
Hardware Connection using NAD DMIC as QC Input Device
Klippel KA3
(using internal
AmpCard)
Klippel KA3
3.2 KCS running on Klippel Devices
Hardware Connection using KA3 with AMP Card
Klippel KA3
(using an ex-
ternal Amp)
Klippel KA3
3.2 KCS running on Klippel Devices
Hardware Connection using KA3 with external Amplifier
Klippel APE
EVB
(standalone
evaluation
board)
Klippel KA3
3.2 KCS running on Klippel Devices
Hardware Connection using APE Evaluation Board

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3.1 KCS running on Nuvoton Platform (NAD)
General System Overview
Transducer
Amplifier
u(t)
i(t)
Enclosure
KCS
firmware
KCS Monitor
NAD Eval Platform
Sound
enhancement
QC System
Microphone
PC
Nuvoton A6
Tuning Tool
stimulus output sound pressure signal input
KLIPPEL dB-Lab
control control & diagnostics
Figure 1: Schematic Diagram of Evaluation Environment using NAD board
Hardware Connection using KA3 as QC Input Device
Klippel KA3
Microphone
NAD Eval Platform USB
Left Audio
Channel Right Audio Channel
+
-
+
-
Transducer
Enclosure
Distance approx. 5-10cm
NAU 83G20 => 12V(DC)
NAU83G10 => 5V(DC)
Figure 2:Hardware Connection using NAD board and KA3

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Hardware Setup Klippel GmbH Controlled Sound
Hardware Connection using NAD DMIC as QC Input Device
DMIC
Transducer
Enclosure
KLIPPEL
Dongl e12345
KLIPPEL Dongle
Distance approx. 5-10cm
USB
Left Audio
Channel Right Audio Channel
+
-
+
-
NAD Eval Platform
Bottom side of circuit board
(with small hole) pointing to
speaker as shown on right-
hand side
NAU 83G20 => 12V(DC)
NAU83G10 => 5V(DC)
Figure 3:Hardware Connection using NAD board with DMIC
3.2 KCS running on Klippel Devices
General System Overview
Transducer
Amplifier
u(t)
i(t)
Enclosure
KCS
firmware
KCS Monitor
KA3
QC System
Microphone
PC
stimulus output sound pressure signal input
KLIPPEL dB-Lab
control & diagnostics
Figure 4: Schematic Diagram of Evaluation Environment

Klippel GmbH Controlled Sound Hardware Setup
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Hardware Connection using KA3 with AMP Card
Klippel KA3
Microphone
Transducer
Enclosure
Distance approx. 5-10cm
Figure 5: Hardware Connection using KA3 with AMP Card
Hardware Connection using KA3 with external Amplifier
Klippel KA3
Microphone
Transducer
Enclosure
Distance approx. 5-10cm
AM P
InputOutput
External amplifier
Figure 6: Hardware Connection using KA3 with external amp

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Software Setup Klippel GmbH Controlled Sound
Hardware Connection using APE Evaluation Board
PC:
• KCS Monitor
• QC-Software
APE EVB
IN2
IN1
POWER
USB OUT1
OUT2
Audio Weaver®
KCS
Speaker
KA3
Microphone
Distance approx. 5-10cm
Figure 7: Hardware Connection using APE EVB
4Software Setup
1. (only applicable for Nuvoton device): Ensure that the Nuvoton Audio Development Platform
(NAD) is configured as active output device in Windows sound settings. Make sure the output
is unmuted and the volume level is set to 100%.
2. (only applicable for QC measurement with NAD board DMIC): Ensure that the NAD board is
configured as active input device in Windows sound settings. Make sure the input is un-
muted and volume level is set to 100%.

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3. If Klippel QC is used the first time, a microphone calibration needs to be performed by starting
dB-Lab and performing following steps:
a. KA3 used as QC input device
(1) Select in Menu: Hardware -> KA3 -> Amp Calibration for QC Operations
(2) Push button Calibrate Sensor in displayed pop-up
b. NAD board DMIC used as QC input device
(1) Select in Menu: Hardware -> 3rd party audio device -> Device Calibration for
QC Operations
(2) Push button Calibrate Sensor in displayed pop-up
(3) Push button Configure Hardware in property page of QC calibration operation
(4) Deactivate “Use Default Device” and Select DS: Default Playback and DS: De-
fault Capture as QC output respectively QC input device. Leave other settings
unchanged and confirm configuration with button OK.
(5) Login to QC operation ( )
4. Open the property page of the calibration operation for further steps of microphone calibra-
tion. Select Task Microphone/Sensor Calibration, assign a Sensor name, configure Type Micro-
phone and enter MIC1 - Sensitivity and MIC1 –Max Level (peak) from the specification of the
used microphone. (On using NAD board DMIC: Sensitivity = -42dBFS & Max Level (peak) = 125
dB)
Close the property page. Then press in result window Control Panel, wait
until calibration is performed successfully. Push button Save to store the calibration data un-
der a desired name and close this instance of dB-Lab.

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Software Setup Klippel GmbH Controlled Sound
5. Open the database KCS Evaluation Template.kdbx in dB-Lab (dB-Lab instance further called
db-Lab-QC)
6. Configure the global inputs and outputs to be used for QC measurement by performing fol-
lowing steps dependent on the used QC measurement hardware:
a. KA3 used as QC input device
(1) Select in Menu: Hardware -> KA3 -> Signal Configuration
(2) Set Mic Input in Section QC to Laser Card: IN 3,4 (IEPE)
(3) Configure Output in Section RnD + QC to XLR Card: OUT 1,2
(4) Push button Select Sensors… at input field Mic 1 Sensor and select the calibration
file which contains the sensor name given during recently performed calibration
process
(5) Close dialog
b. NAD board DMIC used as QC input device
(1) Select in Menu: Hardware -> 3rd party audio device -> Select Sensors
(2) Select DS: Default Capture in drop-down list Device
(3) Deactivate option Use Default Settings for This Device
(4) Mark Channel 01 by left mouse button click
(5) Push button Select Sensors and select the calibration file which contains the sen-
sor name given during recently performed calibration process
(6) Close dialog

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7. db-Lab-QC: Select the correct KCS evaluation template object based on your KCS device and
QC input device for all subsequent steps of your evaluation process
KCS Device = NAD board
& QC input device = KA3
KCS Device = KA3 or APE EVB with AmpCard/internal amp
& QC input device = KA3
KCS Device = NAD board
& QC input device = NAD board DMIC
KCS Device = KA3 with external amp
& QC input device = KA3
8. db-Lab-QC: Log in to one of both QC operations (dependent on tutorial, see appropriate chap-
ters for details) located below the selected folder by selecting operation and pushing (Only
one active login to a qc operation possible at the same time. Log off from active QC operation
by pushing and log in to other QC operation to switch to that QC operation)
9. Open a second instance of dB-Lab and make sure the KCS Monitor operation belonging to the
DUT is running in this dB-Lab instance. (This dB-Lab instance further called db-Lab-KCS).
10. Arrange the windows of both dB-Lab instances side by side
dB-Lab KCS dB-Lab QC

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Klippel GmbH Controlled Sound
5Tutorial 1 –Check Setup
Goal: Verify that the hardware and software setup is done correctly.
Required QC template operation: QC KCS Evaluation –Sweep
1. db-Lab-KCS:Ensure that KCS control mode is (result window State)
2. db-Lab-QC: Perform a QC measurement ( ) and carefully listen to the audible
sound output. All setup steps were done correctly, if short noise signal followed by fre-
quency sweep signal is audible and no error is shown in QC operation summary window.
If error 70 occurs and no signal is audible at all, probably the speaker is not connected or a wrong
speaker not matching the ID data is connected, the KCS operation is not running or the audio gain
of the KCS operation or the stimulus level of the QC operation is set too low. This error also can
occur if the wrong evaluation template not matching the correct hardware setup is used.
If error 70 occurs and only the short noise signal but no sweep signal is audible, probably the
microphone is not connected/activated or IEPE/phantom power supply is switched off, a wrong
microphone input is configured, the audio gain of the KCS operation or the stimulus level is set
too low.

Klippel GmbH Controlled Sound Tutorial 2 –Measuring the Frequency Response
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6Tutorial 2 –Measuring the Frequency
Response
Goal: Measuring the active speaker’s frequency response in the small signal domain using the
Klippel QC system. This measurement can be used to set up the alignment and equalizer settings.
Required QC template operation: QC KCS Evaluation –Sweep
1. db-Lab-KCS: KCS should be turned on (result window State: ).
2. Perform a QC measurement (db-Lab-QC:). Make sure that the voice coil displace-
ment is considerably below the mechanical protection limit xprot (db-Lab-KCS: see Displace-
ment chart). If necessary, reduce the stimulus level of the Sound Pressure task.
Stimulus Level
dB-Lab QC
dB-Lab KCS
Stimulus Level
set up correctly
Stimulus Level
too high
3. db-Lab-QC:The measured frequency response of the system in the small signal domain is
shown in result window Frequency Response.
4. (optional) db-Lab-QC: Compare multiple measurements, e.g. taken at different microphone
positions or to compare equalizer settings, by using the Limit Mode which overlays all meas-
ured curves. Navigate to the property page’s Limits tab and press Activate Limit Calculation
Mode.

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Tutorial 3 –Active Speaker Evaluation Klippel GmbH Controlled Sound
7Tutorial 3 –Active Speaker Evaluation
Goal: Quick evaluation of the performance of the active speaker with and without KCS in the
large signal domain.
Required QC template operation: QC KCS Evaluation –Sweep
Note: Perform this measurement with activated bass boost and equalization, comparable to the target
application! Turn off nonlinear audio enhancement algorithms such as compressors and virtual bass
as they produce nonlinear distortion, which would make it difficult to interpret the results.
Configure and Perform Measurements
1. db-Lab-KCS:Ensure the KCS is switched on (result window State: )
2. db-Lab-QC:Perform a QC measurement ( ). Adapt the stimulus level of the task
Sound Pressure in the property page until the voice coil displacement is close to the protec-
tion limit xprot (db-Lab-KCS: see Displacement chart). Make sure that the protection system
stays inactive (db-Lab-KCS: see Protection chart).
The stimulus level of the SPL task must not exceed -0.5dB as clipping can occur. Increase the KCS Audio
Gain (db-Lab-KCS: Property page) if more gain is required.
Stimulus Level
Stimulus Level
too high Stimulus Level
set up correctly
Stimulus Level
too low
dB-Lab QC
Stimulus Level > -0.5dB? => Increase Audio Gain
dB-Lab KCS
dB-Lab KCS

Klippel GmbH Controlled Sound Tutorial 3 –Active Speaker Evaluation
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3. db-Lab-QC:Navigate to property page tab Limits and press Activate Limit Calculation Mode
to easily compare measurements.
4. db-Lab-QC:Enter text “ON”into input field SN located in QC control panel and perform a QC
measurement.
5. db-Lab-KCSSwitch to KCS-Mode .
6. db-Lab-QC:Enter text “OFF”into input field SN located in QC control panel and perform a
new measurement.
Important: To get support from Klippel and for the KCS approval process you always need to provide
the QC operation as well as the appropriate KCS Monitor operation containing measurement data.
Evaluating Results
Rub+Buzz (rel.) Curve
Goal: This curve reveals irregular and impulsive distortion caused by e.g. rubbing or bottoming
of voice coil, amplifier limiting, etc. This kind of distortion is very critical and must be avoided
because of a low audibility threshold.
Evaluation step: Check both rub+buzz (rel.) curves shown in result window Rub+Buzz (rel.).
Expected result: Neither of the curves exceed the limit of approx. -20dB which indicates high
impulsive distortion. If the limit is exceeded, refer to section How to Treat Rub+Buzz Issues.
Figure 8:Example Rub&Buzz curves
Distortion Curve
Goal: Verify that the active speaker system including KCS is working as expected. This in-
cludes:
•correct hardware connection
•initial KCS data fits to the speaker
•KCS algorithm models the speaker correctly

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Tutorial 3 –Active Speaker Evaluation Klippel GmbH Controlled Sound
Evaluation step: Compare the total harmonic distortion curves shown in result window Dis-
tortion.
Expected result: The THD measured in KCS ON mode should be lower than the THD meas-
ured with KCS in control mode KCS OFF + EQ.
Distortion reduction
Figure 9: Example THD curves
Frequency Response Curve
Goal: Symmetric speaker nonlinearities cause compression in the acoustical output at high
voice coil displacement and/or velocity. Evaluate the KCS linearization feature which com-
pensates these compression effects.
Evaluation step: Compare the frequency response curves shown in Frequency Response win-
dow.
Expected result: In the frequency range where the voice coil displacement and/or velocity is
high, the magnitude of the frequency response in KCS ON mode is higher than without KCS.
The curve shape is almost identical to the small signal measurement but with a higher level.
Decompression effect
Figure 10:Example frequency response curves

Klippel GmbH Controlled Sound Tutorial 4 –Evaluate Mechanical Protection System
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8Tutorial 4 –Evaluate Mechanical Pro-
tection System
Goal: KCS prevents mechanical overload and allows to increase the SPL even if the transducer is al-
ready operated at its mechanical limits. This section explains how to evaluate the mechanical protec-
tion system.
Required QC template operation: QC KCS Evaluation –Sweep
Configure and Perform Measurement
1. db-Lab-KCS:Ensure the KCS is switched on (result window State: )
2. db-Lab-QC:Perform a QC measurement (db-Lab-QC:). Adapt the stimulus level
of the task Sound Pressure in the property page until the voice coil displacement is close to
the protection limit xprot, as explained in Tutorial 2 - Configure and Perform Measurements)
3. db-Lab-QC:Navigate to property page tab Limits and press Activate Limit Calculation Mode
to easily compare measurements.
4. db-Lab-QC:Enter an identifier for the reference measurement, e.g. “Ref”,into the input field
SN located in QC control panel and perform a QC measurement.
Ref
5. db-Lab-KCS:Open the property page and memorize the actual Audio Gain.This value will be
referenced later as Reference Audio Gain.
Reference Audio Gain
6. db-Lab-KCS:Increase the Audio Gain by 6dB
Reference Audio Gain + 6dB
7. db-Lab-QC:Enter “+6dB”into input field SN located in QC control panel and perform a QC
measurement
8. db-Lab-KCS:Increase “Audio Gain” by a further 6dB (Resulting Audio Gain = Reference Audio
Gain + 12dB)

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Tutorial 4 –Evaluate Mechanical Protection System Klippel GmbH Controlled Sound
Reference Audio Gain + 12dB
9. db-Lab-QC:Enter text “+12dB”into input field SN located in QC control panel and perform a
QC measurement
10. db-Lab-QC:Push button Calculate to update the values and curves displayed in the result
windows
Important: Reset the KCS Audio Gain (db-Lab-KCS) to the Reference Audio Gain after the measure-
ment.
Evaluating Results
Frequency Response Curve (dB-LAB-QC)
Goal: Evaluate the influence of the protection system on the system’s frequency response.
Evaluation step: Compare the three frequency response curves shown in result window Fre-
quency Response.
Expected result: Once the modeled displacement reaches the protection limit xprot, an
adaptive high pass filter with variable cut-off frequency activates to prevent mechanical
overload. The high frequency SPL is still increased in 6dB steps.
High frequency content
still increased with raising
levels
High-pass filter cutt-off
frequency shifted upwards
with raising levels
+6dB
+6dB
Figure 11: Example frequency response curves
Mean Sound Pressure Level (dB-LAB-QC)
Goal: Evaluate that the mean SPL can be further increased although the speaker already op-
erated at its mechanical limits.

Klippel GmbH Controlled Sound Tutorial 4 –Evaluate Mechanical Protection System
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Evaluation step: Compare the sound pressure level determined during the three measure-
ments shown in result window Summary.
Expected result: The mean sound pressure levels of the subsequently performed measure-
ments increase on higher gain levels, even when the protection system was active.
Mean SPL increases with
raising level
Figure 12: Example mean SPL values
Displacement and Mechanical Protection Curves (dB-LAB-KCS)
Goal: Evaluate that the mechanical protection of the KCS ensures that the maximum defined
working range is not exceeded and no mechanical overload situation occurs.
Evaluation step: Check the displacement curves xpeak/xbottom recorded during the three
QC measurements and the appropriate mechanical protection curve G cx (mechanical).
Expected result: The displacement did not exceed the defined working range limit xprot dur-
ing the three QC measurements. The attenuation of the protection system agrees approx. to
the attenuation at low frequencies (see Frequency Response Curve in dB-Lab-QC).
Mechanical
Protection
attenuation level
increases with
raising signal levels
Displacement does
not exceed the target
displacement
Figure 13: Example Voice coil displacement and mechanical protection curve

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Tutorial 5 –Multi-Tone Distortion Klippel GmbH Controlled Sound
9Tutorial 5 –Multi-Tone Distortion
Goal: Evaluate the reduction of harmonic and intermodulation distortion in the large signal domain
on applying a multi-tone signal.
Required QC template operation: QC KCS Evaluation –Multi-tone
Configure and Perform Measurements
1. db-Lab-KCS:Ensure the KCS is switched on (result window State: )
2. db-Lab-QC: The stimulus level of the task Multi-tone needs to be adapted similar as done with
task Sound Pressure in Tutorial 2 –Active Speaker Evaluation to achieve a maximum voice coil
displacement without activating the mechanical protection. Therefore, perform a QC meas-
urement ( ) and adapt Stimulus Level in the property page of the Multi-tone task
until the voice coil displacement is close to the protection limit xprot (db-Lab-KCS: see Dis-
placement chart). Make sure that the protection system stays inactive (db-Lab-KCS: see Pro-
tection chart).
The stimulus level of the Multi-tone task must not exceed -0.5dB as clipping can occur. Increase the
KCS Audio Gain (db-Lab-KCS: Property page) if more gain is required.
3. db-Lab-QC: After configuration of sufficient stimulus level, navigate to property page tab Lim-
its and press Activate Limit Calculation Mode to easily compare measurements.
4. db-Lab-QC:Enter text “ON”into input field SN located in QC control panel and perform a QC
measurement.
5. db-Lab-KCSSwitch to KCS-Mode .
6. db-Lab-QC:Enter text “OFF”into input field SN located in QC control panel and perform a new
measurement.
Evaluating Results
Multi-tone Distortion Curve
Goal: Speaker nonlinearities create harmonic and intermodulation distortion on applying
stimulus signal containing multiple frequencies which are compensated by KCS.
Evaluation step: Compare the multi-tone distortion curves shown in Multi-tone Distortion
window.