1

What's New in QC Version 5.0? Overview - General Features (QC Standard Version)

Windows 10 supported (+ Win 7, 8; last version supporting Win XP)

New version of the QC System:

QC Stand-alone Software – perform measurements with any 3rd audio interface

Multiple level measure added to SPL and SPL+IMP

New limit mode for Rub & Buzz: Relative to average level

New calculation mode of harmonics: IEC61286

New acoustic phase calculation removing delay

Online statistics of yield (overall + individual statistic)

Process control : Nelson, Weco or customized rules

Resizable property pages

Impedance Task:

o 4th

order fitting added (vented box parameters)

o Improved measurement of resistive loads

o Pre-loop adjustable for faster testing

o Measure minimal impedance

Live-Monitoring of microphone signal

Yield Statistics: new user interface

Manual Sweep: live analyzer added incl. waveform, spectrum, signal characteristics

User defined windowing of frequency response

Changing setup without discarding Reference DUTs

Improved version control for external references / absolute limits

Settings & limit import unified and extended, feature added to more modules (SPL, SPL+IMP, IMP,

MSC, EXD, EQA); complete test can be configured from external text file

Simplified calibration process (one operation only)

Simplified management of optional features

Level definition of digital audio devices in dBFS

Online detection of new Golden DUT

Reference data supported from any version ≥ QC2.8

Overview - New & Updated Modules

ALS Air Leak Stethoscope (final release)

EQA Equalization and Alignment (final release)

LST Linear Suspension Test

o Measure large size diaphragms up to 18’’

o Optional microphone (resonator parameter fitting) for improved accuracy and stability

WHAT'S NEW IN QC VERSION 5.0

2

QC Stand-alone Software

A new software-only version of the QC System has

been released for measurement with universal audio

interfaces (sound cards).

The KLIPPEL Production Analyzer (PA) is the recom-

mended standard hardware for performing tests on

audio devices with the KLIPPEL QC software. This

measurement device is dedicated to reliable opera-

tion in a production environment and is part of the

QC Basic or QC Standard set. For testing passive

devices (transducers), the Production Analyzer is

required as it provides voltage and current sensors

for accurate measurement of electrical parameters

(impedance, T/S parameters, large signal parame-

ters).

Figure 1 Example setup for testing an active speak-

er with an external soundcard using the QC soft-

ware

However, some testing applications, such as purely

acoustical or line level tests, do not require the spe-

cific features of the PA. A compact USB audio inter-

face may be preferable, especially for mobile testing

applications such as

installed speaker diagnostics,

measurement in car interior,

on-site quality check of rental equipment

and many more.

The QC 5 Stand-alone Software may be purchased

and operated independently from the PA hardware,

only a USB license dongle is required. Virtually any

audio device which provides an ASIO or Windows

Direct Sound driver may be used as measurement

interface. This software version is dedicated to cost-

efficient testing solutions using 3rd

party audio inter-

faces. The Production Analyzer hardware and im-

pedance based measurements are not supported by

this version of the QC System.

Online Statistics Extended – Control

Rules

Control rules (aka zone rules) are a common tool to

monitor whether a process is under control or not.

These rules evaluate the time course of test results

in so-called control charts, which are based on the

moving average and statistical spread of passed

DUTs (devices under test). Well-known rule sets

such as Nelson or WECO rules are provided by the

QC System, but user defined control rules may be

added as well. The picture below illustrates a control

rule example: the resonance frequency fs shows a

trend of six constantly increasing values.

Figure 2 Illustration of a control chart for resonance

frequency (left); Corresponding summary output of

QC Test (right)

By that, scalar test results of the QC system such as

resonance frequency or voice coil offset (MSC add-

on) can be monitored in the background and

checked for the defined rule set automatically. In

case the condition of at least one rule is fulfilled, it

will be indicated in the result window right next to

the individual and overall test verdict. It is possible

to forward a control rule violation to the GPIO of the

Production Analyzer hardware for automated envi-

ronments.

WHAT'S NEW IN QC VERSION 5.0

3

Impedance Measurement - Vented

Box T/S Model Added

The Thiele/Small linear parameter fitting algorithm

of the QC System has been extended for vented box

systems.

Figure 3 Example for 4th order loudspeaker sys-

tems

The standard Impedance measurement task pro-

vides the impedance magnitude and phase as well as

the Thiele/Small parameters (fs, Qts, …). They are

based on a lumped parameter model of the electro-

dynamic transducer (2nd

order) which is fitted to

agree with the measured data. So far, the model

could only be applied to drivers in free air or mount-

ed in a closed test box. For more complex systems,

only impedance could be tested.

Figure 4 Measured and fitted impedance of a vent-

ed speaker system

To extend the model for more complex systems, two

new modes have been added for impedance fitting.

The mode Driver in Vented Box is based on a 4th

order vented box model and it may be applied to

any system with a single driver mounted in an enclo-

sure containing a vent or a passive radiator. This

ensures correct estimation of driver parameters.

Additionally, two new parameters referring to enclo-

sure parameters are available:

fb – Enclosure resonance frequency

(port/passive radiator)

Qb - Total enclosure Q including all enclosure

and vent losses.

Note that the Motor+Suspension Check (MSC) add-

on for fast large signal parameter testing also sup-

ports 4th

order systems.

Manual Sweep Scope & Live

Monitoring of Mic Signal

The manual sweep sine tone generator is a valuable

tool for manual diagnostics of critical units or prob-

lems in the test setup. This feature has been extend-

ed by a real-time scope and controller function.

Failed DUTs can be analyzed while mounted in a test

jig using the response waveform, spectrum and

signal characteristics (peak, RMS etc.).

Figure 5 Schematic overview of driver test setup

with manual sweep diagnostics and live monitoring

For mouse-free operation, KLIPPEL now provides a

new accessory for the QC System: the Manual Sweep

Controller. This universal 3D controller is connected

to the test PC via USB. It enables the operator to

control the frequency and voltage setting of the

WHAT'S NEW IN QC VERSION 5.0

4

manual sweep continuously in an intuitive way

without any additional mouse operation.

Live monitoring of the measurement signal is anoth-

er brand new feature which is a valuable upgrade for

the manual sweep function. Any measurement per-

formed with the QC System may be monitored in

real time using headphones for subjective acoustical

evaluation. Handling is simple; the captured micro-

phone signal is streamed to the standard audio de-

vice (e.g. internal sound card) of the host PC.

Update of Linear Suspension Test

(LST) Add-on

QC5 comes with an updated version of the LST add-

on module for fast testing of suspension parts (spi-

ders, cones, passive radiators) introducing model-

based parameter fitting.

So far, the LST has used laser displacement meas-

urement only. An additional microphone provides

the transfer function between sound pressure and

displacement. This is the base for a resonator pa-

rameter fitting algorithm providing more accurate

results and improved robustness. The technology

has been adapted from SPM Lite module of the

KLIPPEL R&D System.

Figure 6 Principle of LST two signal method

A major benefit of the new measurement technique

is the measurement of parts with a large surface. For

this reason, the SPM Bench has faced an update as

well in order to meet the QC requirements (fast,

upright mounting). Using this equipment, parts with

a diameter of up to 18’’ may be tested.

Figure 7 testing an 18'' cone on the SPM Bench with

QC LST

Import of Setup Parameters and

Limits

Since QC version 4, selected test settings and limits

may be imported from a plain text file. In QC5 this

infrastructure has been generalized to allow com-

plete test setup and limit configuration from exter-

nal files.

Figure 8 Test configuration using text file settings

import

This general settings import may be used for differ-

ent applications such as:

WHAT'S NEW IN QC VERSION 5.0

5

Applying local settings that are specific for a

certain test station (e.g. equalization data for

frequency response)

Exchanging settings between tasks (e.g. online

equalization of reference sound source)

Automated test configuration using external

framework software

Accelerate test setup for repeated settings

(similar tests or multi-channels tests)

and many more.

The simple file format is fully compatible to the

settings log files which are generated automatically

by the QC system for traceability. Therefore, it is

possible to backup and restore setup modifications

easily.

Relaxed Coupling of Setup and

Reference DUTs

By default, the measured reference data for limit

calculation is tightly connected to the measurement

setup, ensuring reasonable and traceable test limits.

This coupling is designated as Reference DUT Integri-

ty. Once reference DUTs are recorded, the meas-

urement setup is protected from modification. How-

ever, display parameters and other non-

measurement relevant settings (e.g. digital in- and

output) can always be modified.

Special applications may require modifying the setup

without any consequences for reference DUTs. Typi-

cal applications are

Use of absolute limits

Use of floating limits

Setup independent limits.

For those cases the tight coupling can be relaxed. As

a consequence, most parameters may be modified

freely, without discarding reference units or limits.

Existing limits are automatically adjusted in case

frequency range and resolution have changed (for-

mat changes).

Windowing of Impulse Response

Impulse response windowing is a common approach

to suppress room reflections (at higher frequencies)

for testing audio systems in a room without anecho-

ic treatment.

Figure 9 Comparison of impulse and frequency

response with and without windowing

This feature has been added to the QC standard

tasks Sound Pressure and combined SPL+IMP. The

window type, length and automatic delay alignment

may be controlled by the user.

Rub&Buzz Testing Relative to

Average Level

A new relative limit calculation mode has been in-

troduced for Rub&Buzz distortion.

Defining testing limits relative to approved reference

units is a common approach in end-of-line testing.

Result deviation caused by the test environment can

be handled by simply shifting the reference average

(or overall max) by a certain tolerance.

Setting reasonable limits can be challenging, espe-

cially for Rub&Buzz distortion (irregular defects,

black solid curve). Comparing the SPL of the distor-

WHAT'S NEW IN QC VERSION 5.0

6

tion relative to the fundamental (main signal) is a

simple but effective approach to evaluate severity of

defect distortion.

Figure 10 Result plot illustrating Rub&Buzz limit

definition relative to the average level of the fre-

quency response

A new limit calculation mode allows defining the

Rub&Buzz testing limit relative to the average level

of the frequency response (reference pool). In com-

bination with the normal shift algorithm, this can be

used as a floor option to prevent the limit from fall-

ing below a defined relative threshold. This improves

robustness for false rejects.