A complete PC based electroacoustic analyzer package for measuring loudspeaker systems ...

LoudspeakLoudspeaker Measurer Measurement Systemement SystemVVersion 4 .0 fers ion 4 .0 f or or WindoWindo ws®ws®

... at a completely affordable price!

A complete and affordable analyzer system that provides quality data suitablefor real electroacoustic engineering purposes. The LMS system provides a vastarray of powerful computer based features which are specifically focused onthe unique requirements of loudspeaker development and QC production test-ing. Whether your application is professional audio, consumer stereo, carstereo, or contract installation, LMS is the perfect tool for development andtesting of loudspeaker systems. No other measurement package today providesas many outstanding features and capabilities at such an incredible price!

LMS is a swept sine wave analyzer for PC computers and consists of an ISAfull length PC slot card, connector interface cables, the Windows® based appli-cation software, and includes a calibrated M31 microphone. LMS can be usedfor production QC testing of loudspeakers, engineering/development of loud-speakers, and a wide array of general purpose electroacoustic measurements.

Unlike FFT type analyzers, LMS provides log resolution of frequency datapoints, while still maintaining the ability to gate signals for quasi-anechoic SPLmeasurements! Since LMS measures frequency response directly, very littleCPU overhead is required since there is nocomplex FFT transform to solve.

All graphics are designed on an artboard in true WYSIWYG fash-ion. The screen display is identical to the printed output. The userhas full control over many of the design elements of the artworkincluding fonts, colors, and line styles. Custom graph documenta-tion is also provided for project name, person, and company. Noteand comment areas are also included in the graph layouts. Fullhigh resolution color printing is supported through any standardWindows® printer driver.

The LMS system will also generate a TTL pulse which can beused to control external switching of test fixtures, or direct polarplot sweeps using stepper motor driven turntables. For productiontesting applications the LMS software can be controlled by userwritten Macro programs. The LMS Macro programming languageallows for messages to be written to the screen to prompt opera-tors, control test sweeps, run utilities, control printing of graphs,export data, and conduct Pass/Fail tests.

Loudspeaker Measurement System

The rich graphical user interface provides ahost of features which greatly enhance theease of operation and power of the system.

Unlike other analyzer software, LMS con-tains a Curve Libraryarchitecture. Up to 50 curves can be stored in each library. Multicurve display was not an after thought in LMS, it was built-in from the ground up. This alsoprovides tremendous power and flexibility for post processing operations. Many applicationsrequire multi curve data to perform various tasks, such as multiplying two curves together,using two impedance sweeps for generating speaker parameters, etc. The Curve Librarymakes all of this possible and more.

All of the LMS hardware features can be controlled and modified through the Analyzer Parametersdialog. The analyzer control parameters can also be saved to disk as QuickSetfiles, and recalledlater to immediately reset all of the control panel parameters. The user can save and retrieve previ-ous setups for any number of favorite test measurements. Sweeps can be taken over any frequencyrange from 10Hz to 100kHz. Any number of data points can be measured from 2 to 800.

Eight data measurement modes are supported:•Volts •SPL •Impedance •RT60•Inductance •Capacitance •Polar Volts •Polar SPL

Person: Company:

Project: File: 1207cap1.lib

Jul 20, 2000Thr 5:41 pm

4.1.0.243Jul/19/2000

No

tes

Map

1: 1618852: 1618863: 161887

4: 1618885: 1618896: 161890

7: 1618918: 1618929: 161893

10 Hz 20 50 100 200 500 1K 2K 5K 10K 20K 40K

dBSPL

-28

-26

-24

-22

-20

-18

-16

-14

-12

-10

-8

-6

-4 Deg

-180

-150

-120

-90

-60

-30

0

30

60

90

120

150

180

SPL vs Freq

The LMS system also includes its ownpre-calibrated measurement microphone.Absolute scaled SPL measurements aremade at the touch of the mouse!

■ Processing OperationsThe Processing menu pro-vides mathematical functions,data processing functions, andother specialized curve pro-cessing capabilities which canbe applied to measured dataor imported data. Smoothing,scaling, splicing, phase gener-ation and math operationsgive the user complete controlover the measured data with-out the need for using exter-nal data processing programs.

■ Utility OperationsLMS provides a rich set of utilities for manipulating dataand graphics. Numerical data can be imported andexported from the program as simple ASCII text files.The graphic artwork can be exported as either vector orraster image files in many different formats including:BMP, TIF, PCX, PNG, EPS, AI, PDF, WMF, EMF. Apowerful Curve Captureutility can distill numerical curvedata from raster images. These can be pictures frombooks, manuals, or scanned images of plotter output. TheCurve Editorutility allows you to graphically create yourown curves, or edit the data of any curve in the library.

■ Speaker Parameter DerivationThis dialog provides five different methods of gener-ating speaker parameters. Moreover, the parametersgenerated can be produced for two different models:Standard or LEAP. The numeric parameters can beprinted, saved to a file, or copied to the clipboard.

Full optimization of the model parameters to theoriginal impedance curves is provided for maximumaccuracy. Native unit conversions are provided forall parameters. For example, an edit field for lengthcan convert and display Inches, Meters, Feet, etc.

The dialog also provides the means to generateimpedance curve simulations based on the derivedparameters. This allows for easy viewing and com-parison of the model to the actual measured imped-ance data.

■ Scale ParametersThe Scale Parameters dialog consists of two principal groups ofcontrols: Horizontal Scales and Vertical Scales. This powerfuldialog enables plot-ting of curve data inalmost any possiblemanner. A differentscale is defined foreach type of curveunits. The horizontalpanel provides controlover the frequency,time, or angle unitscales. The verticalpanel controls a widevariety of differenttypes of unit scales.

■ Macro Programming LanguageFor production applications where repetitive testing is required, theLMS system provides macro programming capability. The LMS com-mands allow custom messages to be displayed on the screen, utilities tobe run like compare, and of course graph display or printing of thesweep data curves. A custom macro editor is also provided which fea-tures syntax highlighting and color printing.

LINEARX SYSTEMS INC9500 SW Tualatin-Sherwood RdTualatin, OR 97062-8586 USA

Tel: 503-612-9565 Fax: 503-612-9344www.linearx.com sales@linearx.com

All specifications subject to change without notice.© 2000 All Rights Reserved.Printed in the U.S.A.07/20/2000

Minimum System Requirements■ Mouse and Keyboard■ Full length ISA bus slot (or use PAC4)■ Windows® 95, 98, NT4, 2000■ 50MB free Hard Drive space■ 32MB RAM Memory■ Pentium® 166 or equivalent■ Video 800 x 600 Resolution / 256 Colors■ TrueType® or Adobe® Fonts

Recommended System Requirements■ Windows® NT4 or Windows® 2000■ 100MB free Hard Drive space■ 64MB RAM Memory or more■ Pentium-II® / 350 or equivalent■ Video 1024 x 768 Res / 64K or 16M Colors■ Adobe® Fonts with Adobe Type Manager®

Contact factory for international dealers

Specifications

■ PhysicalFormat ISA 8-bit full length PC slot cardISA Bus Speed 8MHz-16MHzPC card Size 13.2 x 4.2 inchesConnector Interface DB-15 Female

■ Power RequirementsDC Voltages +12V, -12V, +5V, -5VDC Currents 200mA, 200mA, 230mA, 230mAPower Consumption 7 Watts

■ OscillatorFrequency Range Programmable, 10Hz-100KHzSweep Range Programmable, 1/60 octave, 4-DecadesSweep Scale LogarithmicFrequency Resolution 200 Points per Decade, 1% AccuracyDistortion 0.015%, 20Hz-20KHzAmplitude Flatness ±0.1dBAttenuator Step Size 0.25 dBAttenuator Range 0 to -60 dBGating Resolution 0.1mS, Zero Crossing SyncGating Time Range 0.1mS to 6 Seconds

■ State Variable FiltersFilter Complement 2 - 2nd Order Tracking Prog FiltersFilter Functions Flat, 2nd Order: LP, HP, BP, BRFrequency Range Programmable, 10Hz-100KHzOsc Tracking Ratio Any Ratio from 0.1:1 to 10:1Tracking Flatness ±0.25 dBQ Factor HP, LP, BP 1.0BR Notch Depth 40dB Typical

■ AnalyzerMeasurement Range +20dBm to -70, 90dB Dynamic RangeDetection Methods RMS Scaled Average, Gated PeakMeasurement Types Precision Settling, HiSpeed sampleGating Resolution 0.1mSGating Time Range 0.1mS to 6 Seconds

■ Line OutputOutput Impedance 500 OhmsMaximum Output +16dBm (5.2Vrms)

■ Line InputInput Impedance 100K OhmsFreq Response -0.5dB 10Hz-100KHzBalanced Input CMR 40dB 20Hz-20KHzMaximum Input +20dBm

■ Microphone InputInput Impedance 100K OhmsFreq Response -0.5dB 10Hz-100KHzMicrophone Supply +8.75Vdc @ 5mAMaximum Input +5dBm

■ M31 MicrophoneConstruction Type Condenser Electret ElementInternal Preamp Direct Powered Hybrid Preamp/BufferAccuracy ±1dB cal, ±5dB, 10Hz-40KHzMaximum Level 125dBsplDimensions 8mm/0.351In diameter, 100mm(4In)Finish & Termination Black Anodized Aluminum, 3 Pin XLR

System HardwareThe LMS PC card contains a low distortion sine wave oscillator, dualstate variable tracking filters, mic preamp, and gated peak/average leveldetection circuitry. A line level output is provided, along with a balancedline input, and a direct powered microphone input.

Any of four sources can be selected for measurement, and externalmicrophone preamps can be supported with response calibration. Thebasic frequency range of the system spans 10Hz to 100kHz and fea-tures a dynamic range of 90dB equivalent to 16bit digital audio.

The high resolution of the system allows up to 200 log-spaced fre-quency data points to be taken per decade of frequency. This is equiv-alent to one data point per pixel on the screen.

The filters allow many different types of measurements to be made.The filters can be set for FLAT, LowPass, HighPass, BandPass, andBandReject responses. The accuracy and flexibility of the LMS analyz-er rivals systems costing many times more, and is certainly far easier tosetup and operate for both novice and experienced users alike.

The LMS hardware will run on virtually any computer which provides afull length ISA bus slot. For laptop use, the PAC4 can provide this exter-nal slot capability, and interface to the computer using a serial COMport for communication.