Product Data

Audio Analyzer — Type 2012Version 4.0 including Special Calculation Software Type 7661

USES:

Development and quality control testing of electroacoustic and vibration transducers: loudspeakers, telephones, headphones, microphones, hearing-aids, hydrophones, accelerometers

Linear and non-linear system analysis

Propagation path identification

Acoustical measurements in rooms and vehicles

FEATURES:

Transducer workstation combining the most advanced sine sweep and FFT techniques

12″ high-resolution colour monitor displays up to 36 curves simultaneously

Frequency range: 1Hz to 40kHz

Distortion and noise: <–80 dB re full scale input

Fast time selective measurement of complex frequency and impulse response

Steady-state response measurements as a function of swept frequency or level

Automated measurements of individual Harmonic, Intermodulation and Difference Frequency distortion components and total RMS

1600 line FFT spectrum

User-definable Auto Sequences

Extensive post-processing facilities: +, –, ×, /, 1/x, x2, √x, |x|, poles, zeros, windowing, editing, smoothing

On-screen help in English, French or German

Preamplifier (microphone) and balanced or single-ended direct inputs

Two separate built-in sine generators

Built-in 31/2″, 1.44Mbyte, PC/MS-DOS compatible floppy disk drive for storage of data, setups, and Auto Sequences and simple loading of complete applications

Screen copy facility for plotters and printers, both colour and monochrome, direct or via disk

Upgrade kit from Version 3.0 to Version 4.0 available

The Type 2012 Audio Analyzer is apowerful instrument for transducermeasurements and system analysis. Itfeatures a colour screen, built-in 31/2″floppy disk drive, IEEE-488 and RS-232-C interfaces, three measurementmodes and an Auto Sequence facility.The Time Selective Response mode en-ables extremely fast, accurate, sweptsine measurements of the free-field re-sponse of a transducer in an ordinaryroom up to the 20th harmonic. TheSteady State Response mode enablesstepped sine measurements of Har-monic, Difference Frequency and Inter-modulation distortion. The 2012 alsoincorporates a 1600 line single-channelFFT for spectrum measurements.

Type 2012 has numerous post-pro-cessing capabilities: windowing, blockarithmetic, addition of poles and zeros,square and square root, absolute value,and editing of response data. Applica-tions include development and qualitycontrol testing of loudspeakers, tele-phones, microphones and other elec-troacoustic and vibration transducers.

Brüel & Kjær B K

Introduction

Audio Analyzer Type 2012 offersthree powerful measurement tech-niques in one instrument. Time Se-lective Response (TSR), Steady StateResponse (SSR) and FFT Spectrum(FFT) techniques combined with fullcomplex processing, ensure that Type2012 will solve almost any electroa-coustic measurement problem.

TSR ModeThe TSR mode enables “free-field”measurements without an anechoicchamber, by rejecting the reflectionsfrom an ordinary listening room.Type 2012 incorporates a techniquethat allows a useful combination ofspeed, accuracy and signal/noise ratiofor such measurements.

SSR ModeThe SSR mode offers comprehensivedistortion measurement facilities:Harmonic, Intermodulation and Dif-ference Frequency distortion modes.For band-limited objects, such aselectroacoustic transducers, non-line-arities cannot be evaluated simply bymeasuring Harmonic, Intermodula-tion or Difference Frequency distor-tion at a few frequencies only. Theinclusion of all three distortion modesmeans that measurements can bemade beyond the upper frequencylimit of a test object. This is possiblebecause the distortion componentswill remain inside the working fre-quency range of the object.

FFT ModeThe FFT Spectrum mode has beenspecially developed for optimumanalysis of transient signals in thetime or frequency domains.

DescriptionType 2012 features a 12″ high-reso-lution colour screen. 16 different col-ours can be selected from a palette of4096 colours. Setting up the screenformat for simultaneous presentationof up to 36 curves on one or two graphfields is very simple with Type 2012,and multiple curves are easily pre-sented by using different colours.

The 2012 is simple to operate. The“soft key” system significantly reduc-es the number of keys. The keys areorganized to give a good overview ofthe various functions, and logicalmenus provide a guide for setting upthe analyzer. The soft keys are posi-tioned along the right-hand edge ofthe colour monitor.

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A command-oriented Auto Se-quence facility makes it simple to setup the 2012 to perform a specifictask. Auto Sequences are edited in aspecial menu, and are basically a se-quence of setup changes or controlcommands which are executed in thesame order as they are set up. TheAuto Sequence facility allows you totailor the operation of the 2012 to aspecific application. Five Auto Se-quences, each containing up to 100lines, can be stored in the 2012. AutoSequences can also be saved or readfrom a disk.

Measurement data are alwaysstored as complex frequency func-tions in the measurement buffer orone of the ten result memories —“M 1” to “M 10”. The data in each ofthese memories can then be proc-essed further, as complex numbers,using the Block Arithmetic facility.Fig. 1 gives an overview of the dataflow inside Type 2012.

Measurement results obtained inTSR or SSR mode are calculated asfrequency responses. The frequencyresponse is calculated as the transferfunction (relative response) or as theresponse signal only (absolute re-sponse). Measurements obtained inFFT mode are calculated as spectra.The scaling of a spectrum can beRMS, Power, ASD (amplitude spec-tral density), PSD (power spectraldensity) or ESD (energy spectral den-sity).

The input and output of the ana-lyzer can be calibrated in any desiredunit. Once calibrated, the 2012 levelsettings refer directly to the signal atthe terminals of the measurement ob-

ject. An autorange function exists forsetting the optimum input gain.

For most applications the 2012 isa self-contained instrument. It hasboth direct and microphone inputsand two separate built-in sine signalgenerators for excitation. The DirectInput can be used balanced or singleended. The “Preamp. Input” is usedfor connecting a standard B&K mi-crophone preamplifier and measur-ing microphone.

Graphic presentation and docu-mentation are set up in the ScreenFormat menu. This menu has com-prehensive facilities for documenta-tion and hard copies of parameteroverviews for measurements can eas-ily be made. Two screen pictures witha total of 36 graphs can be storedsimultaneously. The Graph menu isused for setting up the parametersfor the frequency and time domainfunctions. Any desired graph functioncan be displayed after a measure-ment has been performed. A set ofgraph data is calculated based on theparameters in the Graph menu andthe measurement data from themeasurement buffer or one of the re-sult memories. The flexibility of thegraph axis parameters and the pos-sibility for individual graph annota-tions give great freedom for viewingand documenting the results.

A standard “QWERTY” keyboard isdelivered with the 2012. It is used forentering text on graphs and for per-sonal comments on a text page. Thekeyboard can easily be changed to in-clude German or French characters.The analyzer is supplied with Eng-lish, German and French program

Fig.1 Flow-chart showing the basic data flow in Type 2012. Data from the measurementmodule are stored as complex numbers in the buffer memory or one of the ten resultmemories. Graph functions can be calculated and displayed after a measurement isperformed

902056e

Measurement Module

TSR

SSR

FFT

"M 10"

"M 2""M 1"

Memories 1 – 10

(complex data)

Buffer Memory

Block Arithmetic Module (postprocessing–

e.g., Add, Multiply, Log., Window)

(e.g., Magnitude,

Phase, Group Delay)

Display Module

(definition of graph axes)

Curve Storage

A

Live Curve

A

Curve Storage

B

Live Curve

B

Memory Module Curve Storage ModuleCurve Data Calculation

disks. This gives the option of select-ing English, German or French char-acters, as well as displaying helppages in the desired language.

The 2012 has extensive on-linehelp facilities. One status and error-message line appear at the bottom ofthe screen to give immediate help orwarning about the button which hasjust been pushed. A comprehensivefull-screen help page can be obtainedby pressing “Help” and then pressingthe key for which help is required.

Measurement Modes

A Mode menu is used for selectingeither the TSR, SSR or FFT measur-ing mode, or one of the five Auto Se-quences. Measurements are alwaysperformed in the mode selected in theMode menu.

Separate measurement and displayprocessors allow the analyzer to bequickly set up for another measure-ment — even while a measurementis in progress.

Time Selective ResponseThe TSR mode employs a techniquefor measuring a time-selective fre-quency response using a linear con-tinuous sine sweep with constant orfrequency-weighted amplitude. Themain advantage of this technique isits capability of rejecting noise andreflections, even with short measur-ing times.

One of the main applications of theTSR mode is the simulated measure-ment of free-field response, for exam-ple, in evaluating loudspeakers in anormal reverberant environment,thus avoiding the use of an expensiveanechoic chamber. One of the proper-ties of TSR is that the magnitude andphase responses are available in boththe time and the frequency domains.Both the frequency and the time do-main responses are typically availa-ble almost instantaneously.

The driving signal used for TSR isa linear sine sweep, i.e. the instanta-neous frequency is linearly related totime. This linear sweep links timeand frequency together in such a waythat a selection in time — and con-sequently in space — can be obtainedby filtering in the frequency domain,see Fig. 2. An advanced detector al-gorithm ensures that the response iscalculated correctly, independent ofthe selected sweep time.

The synchronism between the exci-tation signal and the filter trackingthe response provides the 2012 withan inherently good signal/noise ratio.The TSR technique offers the optimalcombination of signal/noise ratio andmeasuring time, for almost any prac-tical measuring situation. The basic

Fig.2 The Time Selective Response mode allows the free-fieldresponse of a loudspeaker to be measured in an ordinary room.A linear sweep is used for excitation. Various delays are convertedinto frequency shifts proportional to the delay and sweep rate S.The figure shows the instantaneous frequencies at the moment intime when the generator is at 1000Hz

902057e

1000 Hz 970 Hz

970 Hz

Reflecting surface

Propagation speed c = 344 m/s

1 m≈Corresponding to approx. 3 ms

Sweep rate S = 10 Hz/ms

Floor

940 Hz920 Hz

Fig.3 The 2012 measures the fundamental frequency or selectedharmonic (up to the 20th), in TSR mode. The light raster arearepresents the data which are actually used for analysing theresponse. The sweep range is automatically increased to eliminate“edge effects”. The triangular dark raster areas represent the extradata. The width of the data area is given by the Time Rangewhich is equivalent to the length of the time window

t + T0 S 902058e

Frequency

Time

ƒmax

ƒstop

ƒstart

ƒmin

F = ƒ – ƒstartstop

t0

TS

Sweep time

Settling range

Valid data range for analysis of response

Sweep rate

S = F — TS

Time range

Excitation

Collection of data

Delay

Fig.4 TSR menu with dual graph display. The upper graph shows the frequency responsefor a small loudspeaker measured at 1m distance. The lower graph shows the timeresponse (magnitude of the impulse response) for the same measurement

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parameters which must be consid-ered when setting up a TSR meas-urement are: Frequency Range,Delay, Time Range, and Sweep Time.The relationship between these pa-rameters is illustrated in Fig. 3. De-lay is the time between excitation ofthe measuring object and collectionof the measurement data. TimeRange is equivalent to the length ofthe time window for the measure-ment. Sweep Time is the time it takesto perform a sweep covering the spec-ified frequency range, i.e. the effec-tive measurement time. Whenperforming a measurement, thesweep range entered is automaticallyincreased to keep unavoidable “edge-effects” outside the frequency rangeof interest (see Fig. 3). Choosing alonger sweep time, will improve thesignal/noise ratio proportionally.Hence the sweep time should be cho-sen so that the noise is sufficientlysuppressed. Normally this can easilybe obtained with sweep times of theorder of a few seconds. A number ofaverages (1 to 1024) can also be spec-ified to improve the signal/noise ratiowhich only depends on the total ef-fective measurement time.

Two basic modes can be selected –Baseband or Zoom. In Basebandmode the fundamental is measuredover the entire frequency range up toa specified upper frequency limit. InZoom mode the fundamental or har-monic up to the 20th order is meas-ured over a frequency intervalspecified by a start and a stop fre-quency. In Zoom mode the sweep canbe made in both directions dependingon the specified start and stop fre-

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quencies. The position of the timewindow can be varied around themeasured impulse response to com-pensate for large propagation timesin the measured object. Fig. 4 showsthe TSR Setup menu with a dualgraph display.

Steady State ResponseThe SSR mode employs a techniquefor measuring a steady state re-sponse using stepped sine excitation.The response can be measured as afunction of the excitation frequencyor it can be measured as a functionof the excitation level. The measure-

ment can use an adaptive scan algo-rithm or linear averaging. Theadaptive scan algorithm means thatthe steady state response is meas-ured to the user-specified accuracy inthe minimum possible time. Linearaveraging averages the response ofeach excitation step over a specifiedperiod of time.

For measuring frequency respons-es, SSR mode is desirable for meas-urements at a number of singlefrequencies. The distribution of theexcitation frequencies for an SSRmeasurement can be linear, logarith-mic or user-defined.

Fig.5 Harmonic distortion, Difference Frequency and Intermodu-lation distortion can be measured selectively using stepped sineexcitation in Steady State Response mode, or a broadband totalRMS value, including distortion and noise, can be measured

902059e

Analysis frequency Excitation frequency

HARMONIC MODE

Frequency

Frequency

Frequency

DIFFERENCE FREQUENCY MODE

INTERMODULATION MODE

U

U

U

1 2 3 4 5

f 2 2f 2 3f 2 4f 2 5f 2

–2 –4 –5 –3 1 +3 +5

–2–4–5 –31

+4 +5+3+2

f0

f - f 2f - 2f 3f - 2f 2f - f ff 2f - f 3f - 2f2 1 2 1 21 21 21 2 1 2 1

f - 4f2 1 f - 2f2 1 f + 2f2 1 f + 4f2 1

f - 3f2 1 f - f2 1 f + f2 1 f + 3f2 1

f1 f2

Fig.6 SSR Intermodulation distortion menu and graphical pres-entation for setting up the parameters for measuring Intermodu-lation distortion. This menu is set up for measuring thefundamental, the Intermodulation distortion orders 2, –2, 3, –3,4, –4, 5, –5 and Total Distortion

Fig.7 SSR menu with dual graph display. The upper graph shows the near-field frequencyresponse for a mid-range driver, and also includes the 2nd and 3rd harmonics. The lowercurve shows the corresponding Total Harmonic Distortion as a percentage

A stepped sine signal is used forexcitation in SSR mode. If theadaptive scan algorithm is select-ed, the response is automaticallysampled at each excitation fre-quency or level until the responsehas stabilized to within the speci-fied accuracy. In this way themeasurement is optimized in theminimum time for a given accuracy.If linear averaging is selected, a well

defined average is calculated for aspecified period of time at each ex-citation frequency or level.

The measurement can operate oneither complex or power data. Com-plex data provides phase informationon the response and excellent noisesuppression. Power data ignores anyphase information providing accurateresults, even if the test object has avarying delay.

The SSR mode also incorporatesextensive facilities for measuring dis-tortion. Graphical menus make iteasy to set up the system to performmeasurements of Harmonics, Differ-ence Frequency and Intermodulationdistortion as well as measurementsof the total RMS response includingnoise and distortion. Fig.5 illustratesthe Harmonic, Difference Frequencyand Intermodulation distortionmodes.

Harmonic distortion mode can in-clude any harmonic up to the 20th.Total (including fundamental), TotalDistortion (not including fundamen-tal) or THD can also be specified inthis menu.

Difference Frequency distortion ismeasured by exciting the systemwith two test tones of constant orweighted amplitude, f1 and f2. Thetwo tones are stepped through thefrequency range of interest, whilekeeping a fixed frequency differencebetween them.

Intermodulation distortion is alsomeasured by using two test tones, f1and f2, with constant or weighted am-plitude. f2 is kept at a fixed low-fre-quency, while f1 is stepped throughthe frequency range of interest. Oneof the main advantages of Intermod-ulation and Difference Frequency dis-tortion measurements is that theycan be used for measurements be-yond the upper frequency limit of asystem, (since the resulting distor-tion components remain inside thefrequency range of the system). Fig. 6shows the Setup menu for measuringIntermodulation distortion.

Fig. 7 and 8 show the menu for set-ting up the basic SSR parameters fora frequency response measurementand a level response measurementrespectively. Responses measuredcan be calculated as the transferfunction (relative response) or as theresponse signal only (absolute re-sponse). A frequency sweep or a levelsweep can be selected. Linear, loga-rithmic or user-defined distributionsof excitation frequencies can be se-lected for a frequency sweep. Stepsize can be set to 1/3, 1/6, 1/12, 1/24,1/96-octave and Progressive, i.e. start-ing with the 1/3-octave excitation fre-quencies, then adding the remainingfrequencies to make a 1/6-octavemeasurement and so on until all the1/96-octave frequencies have beenmeasured. Next, the parameters usedfor averaging are specified: selectionof adaptive or linear averaging usingeither complex or power data, accu-racy, delay and averaging time.

Fig.8 SSR menu with single graph display. The graph shows a level response of a hearingaid. The level response (sometimes referred to as the I/O Characteristic) shows the outputlevel of the hearing aid as a function of the acoustic excitation level for a single frequency

Fig.9 FFT menu with dual graph display. The FFT mode allows single-channel meas-urements with excitation from the internal sine generators. The upper graph shows a5 kHz sine signal distorted by asymmetric clipping. The lower graph shows the spectrumof the same signal

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Fast Fourier TransformIn FFT Spectrum Mode an FFT algo-rithm is used for measuring the spec-trum of a signal from a test object.The test object may be excited fromthe internal sine generators in Type2012.

The single-channel FFT mode issuited for the analysis of continuoussignals and for transient signals,where the entire signal to be ana-lyzed fits into the analyzer memory.The FFT mode can be advantageousfor measuring, e.g., backgroundnoise, telephone dialling tones, at-tack/release times of compressor cir-cuits or for a quick evaluation of non-linearities in a test setup.

Two basic modes can be selected —Baseband or Zoom. In Basebandmode the 2012 produces an FFT spec-trum with a frequency resolution ofup to 1600 lines, based on 4096 sam-ples in the time function. In Zoommode (high-resolution mode) a partic-ular center frequency can be selected,and a bandwidth from 1.56Hz to1600Hz can be specified to “zoom” inon this frequency. The resolution inZoom mode is always 513 lines, basedon 1024 time samples. Averaging isused to obtain a statistically reliableresult by reducing the effects of ran-dom variations. Complex amplitudeaveraging or Power averaging can beselected. Fig.9 shows the FFT Setupmenu where a dual graph display isused to illustrate a time signal andits corresponding spectrum.

Auto SequencesAn Auto Sequence is a user-definedsequence of front panel functions. Onthe screen, it appears as a three-col-umn list, including the hard key la-bel, the soft key label and theparameter value (if any), which to-gether constitute the equivalentIEEE-488 bus commands. A “learnmode” is used to make this list bysimply pushing the desired keys. Anyfront panel function, including callinganother Auto Sequence, can be exe-cuted with an Auto Sequence. Fig.10shows an Auto Sequence which willperform a TSR measurement of thefundamental and the 2nd and 3rdharmonic distortion components, dis-play the curves on the screen andfinally make a hard copy of the screenpicture. Editing the five Auto Se-quences, each containing up to 100front panel functions, is extremelyeasy.

Conditional and unconditionalloops can be set up and branchingcan be specified. Branching is con-

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trolled using If-Then-Else commands.Looped execution can be establishedusing the “Do” command. Loops canbe performed a fixed number of timesor as long as a specified condition isfulfilled.

In addition, IEEE-488 interfacecommands that do not have an equiv-alent front panel function can bekeyed in from the external keyboard.

The position of the cursor can alsobe controlled from an Auto Sequence,and cursor values can be transferredto, added to or subtracted from pa-rameter values.

Comments can be inserted intoAuto Sequences, as well as messagesand warnings to be displayed in thestatus line on the screen during exe-cution.

Execution of Auto Sequences canbe carried out in either Single Taskor Multitasking mode. In Single Taskmode each command line is executedbefore the next. This ensures an ex-actly sequential execution. For spe-cial purposes, multitasking can beselected, making use of the analyzer’sparallel analysis capabilities.

The 2012 is supplied with a diskwith a number of Auto Sequenceswhich makes up a tutorial guide.

Processing

MemoryType 2012 has a 4Mbyte internal

memory with a battery back-up forpermanent storage of data. The con-tinuous memory is used for storingthe program source, a complete pa-rameter setup, five Auto Sequences,11 complete result memories, twoseparate screen pictures (Graph Aand Graph B) with up to 36 curvesand user-defined text.

The content of the internal memoryis used whenever the 2012 isswitched on without the programdisk in the disk drive. Switching onor resetting the instrument with theprogram disk in the disk drive willupdate the main program and resetall data. Changing between English,German or French help pages andcharacters, is simply a matter of load-ing the desired version of the pro-gram disk.

Block ArithmeticThe Block Arithmetic menu is used

for post-processing operations yield-ing a complete response function orspectrum as a result. All measure-ment data are stored as complexnumbers, i.e. with real and imagi-nary parts, allowing full complex

Fig.10 Auto Sequences are listed using the equivalent IEEE-488 bus commands. ThisAuto Sequence will perform a TSR measurement of the fundamental and the 2nd and3rd harmonic distortion components, display the curves on the screen and finally makea hard copy of the screen picture

a b

c d

a b

c d

processing to be performed. Data inany of the 11 result memories can bepost-processed. The result is a newset of data which can be stored in anyof the result memories. The list ofpost-processing operations are: Copying data between the 11 re-

sult memories. Multiplying data with a frequency

or a time window (Hanning, Rec-tangular or Rectangular with Han-ning Taper)

Addition and Subtraction (in thefrequency domain)

Multiplication and Division (in thefrequency domain)

Time shifting (linear phase shift inthe frequency domain)

Changing polarity (180° phaseshift)

Calculating the reciprocal (in thefrequency domain)

Calculating the absolute value Calculating the square and square

root of the amplitude in the fre-quency domain

Calculating exponents Calculating natural logarithms Adding poles/zeros Editing values Converting data to a user-defined

frequency format

Display

Screen FormatMeasurement results can be dis-played in various formats. Differentgraph formats are shown in Fig. 10.The Screen Format menu is used toset up the different formats: GraphA (and Graph B) display a singlegraph area for showing up to 36curves simultaneously. Text can besuperimposed on the graph field, ora full text page for user-defined textcan be selected. Graph A & B gives adual screen format to display GraphA (upper) and Graph B (lower) simul-taneously.

Fig. 11 and 12 show some of thescreen formats which are also usedfor documentation. Graph Only isused to give an enlarged graph fieldwhich takes up the whole screen; nomenu is shown. Full TSR, SSR orFFT Setup gives a complete screenoverview of the parameters for therespective menus, together with theparameters from the Level, Inputand Output menus. Graph and TSR,SSR or FFT Setups give the param-eters for the respective menus togeth-er with the Level menu and a graphfield.

Fig.11 Examples of different screen formats which can be selected in the Screen Formatmenu.a) Graph A format for displaying a single graph area with up to 36 curvesb) Graph A & B format for displaying a dual graph with Graph A at the top of thescreen picture and Graph B at the bottomc) Full screen graph (no menu)d) Graph and Text page on the same screen picture

Fig.12 The different screen formats offer the possibility of documenting measurements.When a hard copy is made it is a reproduction of what appears on the screen.a) Graph Only format expands the graph field to cover the entire screen (no menu isshown)b) Full TSR/SSR/FFT Setup format is used for displaying the parameters from therespective menus together with parameters from the Input, Level and Output menusc) Graph and TSR/SSR/FFT Setup format is used for displaying the parameters fromthe respective menus together with parameters from the Level menus, on the left-handside of the screen. The graph is shown on the right-hand side. No menu is shownd) Frequency and amplitude values can be read out directly in all formats using thecursor

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GraphThe Graph menu is used for select-

ing the parameters for presentingmeasurement data in a system of co-ordinates. The desired function andthe real coordinate to be displayedare selected in this menu. Selectingand calculating the frequency andtime domain functions after themeasurement has been done, allowsmeasurement data to be displayed ina number of ways. The followingfunctions and coordinates can be se-lected:

Functions: Frequency Response

1/3-octave Response Time Response Response Decay Frequency Spectrum

1/3-octave Spectrum Time Signal Signal Decay Auto Correlation (only for spectra) Level Response

Coordinates: Real Part Imaginary Part Magnitude Phase Group Delay Instantaneous Frequency

Graph TextThe Graph menu can also be used toenter user-defined text to be dis-played on the screen. Text pages canbe entered in the graph area of thescreen. This text can be displayed su-per-imposed on the graphs, or as puretext with no underlying graph. Textcan be emphasized using user-de-fined text and background colours.This makes it possible to customizeoperator instructions or documenta-tion. A special feature is the “dynam-ic” graph text facility enabling curvevalues and text strings to automati-cally be updated, see Fig.13. This isaccomplished by inserting coded ref-erences (Curve References) into the

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text. X, Y and Z values, Special Cal-culation values (Type 7661 only) andtext strings are then automaticallytransferred to the display. This isparticularly useful for making report-ready documentation. For example,you can set up the analyzer to makeindividual specification sheets with ageneral text and all the relevant val-ues will automatically be insertedinto the text (e.g., set up as a table)when the actual measurements aremade.

CursorThe cursor is used for reading out theexact x- and y-coordinates of a pointon a curve. The cursor x- and y-val-ues can be transferred to a parameterfield by using the “Cursor Value” key.

Input/Output

The 2012 has been designed to meetthe most stringent accuracy specifi-cations. Therefore the advancedmeasurement algorithms arematched by very high-grade inputand output circuits. To ensure thatthe initial specifications are main-tained throughout the operating lifeof the 2012, a thorough, accreditedcalibration is available as a separateservice (see the specifications sectionfor further details).

Analogue InputsThe 2012 has a direct input for voltagesignals and a standard Brüel&Kjærpreamplifier input. Both inputs have adynamic range of more than 80dB andan input signal range from 0.2µV to100V peak. A range of high-pass filterscan be selected for both inputs. Auto-ranging can also be selected for bothinputs. The input/output panel on Type2012 can be seen in Fig.14.

Microphone/Preamp. InputThe 7-pin Brüel&Kjær PreamplifierInput socket supplies power for themicrophone preamplifier, and has a200V polarization voltage which canbe switched off for use with prepolar-ized condenser microphones.

Direct InputVoltage signals are connected via aBNT socket which also accepts BNCcables. The input can be single endedor differential (balanced) which givesa common mode rejection ratio of>70dB at 50/60Hz, enabling the highsensitivity of the preamplifier to be

Fig.13 Curve References can be used for setting up a complete table in a graph text. Thetable above lists the harmonic distortion in dB at selected frequencies

Fig.14 Input/output panel of the 2012, showing the 7-pin Preamplifier Input for con-nection of Brüel & Kjær condenser microphones, and the Direct Input which can be singleended or differential (balanced)

used even in the presence of commonmode noise signals at the input.

Analogue to Digital ConversionThe anti-aliasing filter used in Type2012 is a nine-pole elliptical, low-pass filter, which provides more than80dB attenuation of input frequen-cies which can cause aliasing. Thefilter can be bypassed in FFT mode.14-bit analogue to digital conversionprovides a dynamic range of >80dB.

Trigger FunctionsThe 2012 has a flexible trigger func-tion for use in FFT mode. Delays,from –4 to 32 seconds can be selected,depending on the frequency range.The options available for starting ameasurement are:

Free Run: Averaging begins as soonas the “Start” button is activated.External Trigger: Averaging is ini-tiated by an external trigger signal,with selectable time delay. The trig-ger input is via a BNC socket on thefront panel.

Internal: Averaging starts when theinput signal passes a certain level.The trigger slope can be positive ornegative, and the trigger level can beset from –100% to +100% of the se-lected input value.Generator: Averaging begins whena generator signal with a positiveslope crosses zero level.

Signal GeneratorsType 2012 is equipped with two sep-arate sine generators. The outputs ofthe generators are either fed to twoseparate BNT connectors ( f1 and f2)on the front panel (accepts BNCplugs), or are summed and fed to asingle BNT connector ( f1 + f2).

The output can be set directly interms of the desired working units,e.g. Pa, ms2, once it has been cali-brated. Separate calibration valuesfor “separate” and “common” outputmodes can be stored. An automaticcalibration can be performed with anexternally measured output signal.

The frequency and level of the gen-erators can be controlled directlywith a Manual Generator feature.

The output and input levels are dis-played graphically on the screen.

It is also possible to apply a weight-ing to the generator output. This fea-ture can be used for example, to keepthe sound pressure level from a loud-speaker constant over a specified fre-quency range. This is achieved byspecifying the inverse response of theloudspeaker as weighting for the gen-erator output.

RemoteAn 8-pin socket accepting a standardDIN plug is fitted on the back panelfor remote control. The followingfunctions can be controlled via theremote control socket: Start, Stop,Proceed and Continuous. One pin isused to indicate a “Busy” state andone pin is used for a user-defined in-dication controlled by softkeys.

General

Disk DriveA 31/2″ high-density floppy disk driveis built into the 2012 for permanentstorage of parameter setups, sets ofmeasurement data, Auto Sequences,screen pictures with curves, anduser-defined text. The disk drive canhandle 720Kbyte and 1.44Mbytedisks, and is PC/MS-DOS compatible.

The Disk Input/Output menu canbe used to display a list of files onthe screen, and to perform the follow-ing functions: Store Recall Delete Protect Unprotect Rename Copy FormatIn addition to these standard file oper-ations, the Reset menu includes a cus-tomize function allowing complete set-up of the analyzer (with one keystroke)for a specific application. This is par-ticularly useful when the analyzer isbeing operated by several users.

Screen CopyA copy of the present screen pictureis obtained by pressing the ScreenCopy key on the front panel. A hardcopy file can be output to the IEEE-488 bus, the RS-232 bus or can bestored on a floppy disk. The 2012 issupplied with a number of setups forcommonly used multi-colour pen-plotters, matrix printers, ink-jetprinters and laser printers. If a non-

Fig.15 Type 2012 is ideal for transducer measurements. The setup in the picture usesthe Laser Transducer Set Type 3544 for measuring the Thiele-Small parameters. Use ofthe laser enables measurements without the mass-loading effects of an accelerometer

9

standard printer or plotter is used,there is provision for setting up allprinter or plotter parameters in theInterface menu.

Analogue/Digital Self-testA comprehensive analogue/digitalself-test can be performed to ensureproper operation of the analyzer.During the self-test the 2012 checksits analogue and digital functions.Should a failure occur, a comprehen-sive error code system can be used topinpoint the fault. This minimizesdowntime.

Interfaces

IEC/IEEE-488 InterfaceThe IEC/IEEE interface conforms toIEEE-488.1 and IEC 625-1 stand-ards. All functions on the display, ex-cept those concerning IEEEcontroller functions, can be transmit-ted to and from Type 2012. This in-cludes setup, measurement data,display data, Auto Sequences and ahard copy output. Type 2012 can alsobe used as a system controller via theIEEE-488 interface.

RS-232-C InterfaceThe RS-232-C interface conforms toEIA Standard RS-232-C (equivalentto CCITT V24). This interface isstandard on a number of printers andplotters and is fairly simple to set up.To make a hard copy, the Interfacemenu for the printer or plotter mustbe set up for RS-232. Baud rates be-tween 300 and 19200 can be selected.

KeyboardA standard “QWERTY” type key-board is supplied with Type 2012 forentering text on graphs and for en-tering file names. Extra keys are sup-plied with the keyboard so it can beeasily changed to include German orFrench characters.

Loading the desired language forthe help pages automatically changesthe interpretation of the characters.The keyboard is connected to thefront panel via a DIN-connector.

MonitorMeasurement results are presentedon a 12″ high-resolution colourscreen. The frame frequency can beset to either 50 or 60Hz to avoid in-terference with other mains operatedequipment. An external RGB monitorcan be connected via a D-range socketon the rear panel.

10

Applications

To demonstrate the use of the ana-lyzer in various applications, anumber of examples based on autose-quences are supplied with the ana-lyzer. These examples cover genericapplications within the areas of loud-speaker, telephone and hearing-aidmeasurement. However, the potentialof the analyzer as a stand-alone testsystem as well as a part of a compu-ter controlled system reaches far be-yond these generic examples. Thetypical applications for the analyzerare:

Loudspeaker MeasurementsFig.16 shows a simple setup for mak-ing loudspeaker measurements withType 2012. Using the TSR technique,free-field measurements can be per-formed without an anechoic chamber.

Analysis of cabinet diffraction can bemade in the frequency and time do-mains. Changes in cabinet design caneasily be assessed by displaying thetwo curves simultaneously in differ-ent colours, or by subtracting thecurves and displaying the difference.For R & D work, the 2012 can be usedfor measuring the magnitude andphase of a loudspeaker’s electricalimpedance over its entire frequencyrange. For quality testing, the imped-ance can be measured at a single fre-quency.

The SSR technique in the 2012 hasextensive facilities for making sweptHarmonic, Intermodulation and Dif-ference Frequency distortion meas-urements. These measurements canalso be performed at different excita-tion levels. Defects, such as a rubbingvoice coil, can easily be detected us-ing the FFT Spectrum.

Fig.16 System setup for performing loudspeaker measurements with Type 2012

941410/1e

Audio Analyzer 2012

Preamp.Input

Common Output AO 0506

Audio Power AmplifierWQ 1105

AO 0027

Loudspeaker under test

Tripod UA 0801

UA 0588Microphone Support

UA 0610 Extension Rod

Microphone 4133 Microphone Preamplifier 2639

Fig.17 System setup for performing telephone measurements with Type 2012

941411e

IEC/IEEE–488 Interface Bus

Telephone Interface 5906

Audio Analyzer 2012 Special Calculation

Software 7661

Preamp Input

Direct Input

2 x AO 0087AO 0087

Telephone Test Head 4602 Mouth Simulator 4227

Ear Simulator for Telephonometry 4185

JJ 0225 + AO 0434AO 0265

AO 0506

Sound Source

Ear Simulator

4157

Hearing Aid

under Test

Anechoic Test Chamber

4222

Reference Microphone

Audio Analyzer 2012

4192/2669B

Preamp. Common

Audio Power Amplifier WQ 1105

Brüel

B K7/6-'89

& Kjær

Head and Torso Simulator Type 4128AO 0506

2-Channel Microphone Power Supply 5935

Audio Analyzer 2012 Head and Torso Simulator 4128

with Left Ear Simulator 4159

Preamp Input

Dir. Com.

AO 0087

Audio Power Amplifier WQ 1105

941408/1e

Headphone output

Right

Left

Fig.19 Head and Torso Simulator Type 4128 can be used with Type 2012 for headphonemeasurements. Using 50W resistors, the two single outputs (f1 and f2) are summed, therbyenabling letf- and right-channel measurements to be performed directly

Application Disks with auto se-quences cover advanced applicationssuch as determination of loudspeakerparameters and the combination ofnear-field and far-field measure-ments obtained in an ordinary roominto very accurate free-field respons-es using the post-processing facilities.

Telephone TestingWhen used with the Telephone Inter-face Type 5906, Type 2012 forms apowerful telephone test system. Thesystem illustrated in Fig.17 can beused for measuring transmissioncharacteristics of telephones, includ-ing free-field response of loudspeaker

telephones. Measurements of Re-ceive, Send and Sidetone response aswell as Return Loss, Noise and dis-tortion can be measured. The FFTSpectrum mode can be used for meas-uring the ringer tone, DTMF (DualTone Multi Frequency) and for ana-lyzing the switching characteristicsof hands-free telephones.

Due to the unique measurement al-gorithms, most of these measure-ments can be made simultaneouslywith the presence of real speech sig-nals. This may be required with tel-ephone designs incorporatingadvanced speech detectors and signalprocessing.

Apart from its use as a stand-alonesystem for development and qualityassurance purposes, the 2012 is thecentral component of several PC-con-trolled conformance test systemswhich combine specific national andinternational standards. Separateproduct data sheets are available forthese systems.

MicrophonesThe output weighting facility of the2012 can be used to obtain a soundsource with a flat frequency responsefor testing microphones. Type 2012can be used for free-field (reciprocity)calibration of microphones. The sep-arate generator outputs (f1 + f2) en-able measurements of Intermodula-tion and Difference Frequencydistortion. Variations in the direc-tional characteristics can be dis-played for up to 36 different anglessimultaneously.

Hearing Aid MeasurementsThe analyzer has several encompass-ing facilities for hearing aid measure-ments: Harmonic, Intermodulationand Difference Frequency distortionas well as broadband RMS measure-ments. Output weighting can be usedto compensate for the response of asound source. Results can be func-tions of frequency, time or level asrequired for measurements of fre-quency responses, dynamic responses(for determination of attack and re-covery times) and I/O responses re-spectively. Fig.18 shows the basicset-up for these hearing aid measure-ments using the Anechoic TextChamber Type 4222.

In Situ Measurements of Head-phones, Headsets and Hearing AidsUsing Head and Torso SimulatorType 4128 together with Type 2012enables objective in-situ measure-ments of headphones, communicationheadsets and hearing aids. The setupin Fig.19 can be used for automaticleft- and right-channel frequencymeasurements of headphones. Type2012 can also be used for free-fieldInsertion Gain measurements onhearing aids, i.e., measuring the dif-ference between the frequency meas-ured in the ear canal with a hearingaid fitted, and the open ear frequencyresponse.

Fig.18 System set-up for performing hearing aid measurements with the Audio AnalyzerType 2012

941409/1e

11

Specifications 2012 (Version 4.0)

Input Characteristics:

DIRECT INPUT:Via BNT socket, single ended or balanced input(accepts BNC cables)Input impedance : 1MΩ||100pFCoupling: ACCommon mode voltage: Max. 5VCommon mode rejection:>70dB at 50/60Hz for ð 1V peak input range>60dB at 50/60Hz for Š1V peak input rangeInput ranges: 33 ranges from 3mV to 100Vpeak in a 1, 1.5, 2, 3, 4, 6, 8 sequence

PREAMP. INPUT:Via standard B&K 7–pin socketInput impedance : 1MΩ||100pFPolarization voltage: 0 or 200V from 2MΩsourceHeater Voltage: +6V (at 200mA) from 30Ωsource and +12V (at 200mA) from <1Ω sourceInput ranges: 33 ranges from 3mV to 100Vpeak full scale in a 1, 1.5, 2, 3, 4, 6, 8 sequence

MAXIMUM INPUT VOLTAGE:2012 is a safety class II instrument (IEC 348).For safe operation in accordance with IEC 348,the voltage of the signal ground relative to earthmust not exceed 42V RMS (sine). To ensuresafe operation in accordance with IEC 348 athigher voltages, the user must limit all input cur-rents to 0.7mA peakMaximum input voltage:100V RMS/150 V peak

HIGH-PASS FILTERS:1Hz, –0.1dB. Slope 18dB/oct.20Hz, –0.2dB. Slope 24dB/oct.100Hz, –0.2dB. Slope 24dB/oct.

ANTIALIASING FILTER:Cut-off frequency: 40kHz. Provides at least80dB attenuation of input frequencies which cancause aliasing. The filter can be bypassed inFFT mode

INPUT SAMPLING:Internal: 102.4kHzA/D conversion: 14 bit

CALIBRATION:Units, dB reference and transducer sensitivitycan be keyed into the Input menu. Automaticcalibration with a known calibration source. Thecalibration values for the Direct and Preampinputs are stored individually

FREQUENCY RESPONSE:1Hz to 40kHz, ±0.1dB re 1kHz (with 1Hz high-pass filter)

AMPLITUDE LINEARITY:±0.1dB or ±0.005% of max. input, whichever isgreater

ATTENUATOR ACCURACY:±0.1dB

HARMONIC AND SPURIOUS DISTORTION PRODUCTS:<–80dB re full scale in respective ranges for allattenuator settings

INPUT AUTORANGE:Selects optimum attenuator setting. Can beswitched on or off

Output Characteristics:SIGNAL GENERATOR TYPE:Two sine generators

SEPARATE OUTPUT:Two BNT sockets on the front panel for the twoseparate output signals, f1 and f2 (accept BNCplugs)

COMMON OUTPUT:One BNT socket on the front panel for the sumof the two output signals, f1 + f2 (accepts BNCplugs)

OUTPUT:Voltage:f1 and f2: 100µV to 3.16V RMS in 0.1dB stepsf1 + f2: 50µV to 1.58V RMS in 0.1dB stepsAttenuator accuracy:±0.1dBFrequency Response:1Hz to 40kHz: ±0.1dB re 1kHzHarmonic and spurious distortion products:<–85dB at 3.16V and load >1kΩInherent noise:<–95dB re 3.16V (1600Hz BW)Impedance: f1, f2 and f1 + f2: 50Ω

CALIBRATION:Units, dB reference and transducer sensitivitycan be defined in the Output menu. Automaticcalibration with an externally measured outputsignal in selected unit. Calibration values for f1and f2 in both “Separate” and “Common” modesare stored individually

Measurement Modes:

Time Selective Response — TSRSteady State Response — SSRFFT Spectrum — FFTAuto Sequence 1 to 5

Time Selective Response:RESPONSE:Relative response (transfer function) or absoluteresponse (response signal only) can be meas-ured.

BASEBAND MODE:Fundamental: Frequency Range can be select-ed from 39 Hz to 40 kHz

ZOOM MODE:Fundamental: Start and Stop Frequency can beselected from 1 Hz to 40 kHzMinimum Frequency Range: 39 HzHarmonic Distortion: Up to 20th order harmon-ic distortion can be selected. For the nth orderharmonic distortion Start and Stop Frequencycan be selected from 20 Hz to (40/n) kHz

TIME-WINDOW:50/(N × F), 100/(N × F), 200/(N × F),400/(N × F) and 800/(N × F)N = harmonic, F = frequency range

DELAY:0.0s to 100.0s (max 5 decimals, rounded off tonearest 10µs value)

SWEEP TIME:0.5, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512s

AVERAGES:1 to 4096

PAUSE:0.0s to 100.0s

CONDITIONING TONE:0.0s to 10.0s (max. 3 decimals, rounded off tonearest 10ms value)

Steady State Response:

RESPONSE:Relative response (transfer function) or absoluteresponse (response signal only) can be meas-ured

SWEEP:A sweep of the excitation frequency or the ex-citation level can be selected. A frequencysweep is set up by defining a start and a stopfrequency and a number of steps which can bedistributed on a logarithmic or linear scale or atuser-defined values from 1 Hz to 40 kHz. A levelsweep is set up by defining the excitation fre-quency, the output level range to be swept andthe step sizeLog:1/3, 1/6, 1/12, 1/24,1/48 and 1/96-octave stepsLog ISO: Series R 10, R 20, R 40 and R 80Lin:1 to 1600 stepsUser-defined:From 1 to 50 frequenciesOutput Level: Range and step size for an Output Level sweepcan be selected from 0.1 dB to 80 dB

DETECTOR:Averaging:Averaging can be adaptive to estimate the re-sponse to a user-defined accuracy in the mini-mum possible time, or linear to average all datawithin a specified period of time. Complex orpower averaging can be selectedDetector band:0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.08, 0.1, 0.15,0.2, 0.3, 0.4, 0.5, 0.6, 0.8, 1.0, 1.5, 2, 3, and6dB. The value specifies the required accuracyof the measurement (67% confidence level)when the adaptive scan algorithm is selectedDetector delay :0ms, 10ms, 20ms, 50ms, 100ms, ... 10s. Thevalue specifies the delay before the detector isactivated for each excitation frequencyMaximum detector time:0ms, 100ms, 200ms, 400ms, 800ms, 1.6s,3.2s, 6.4s, 12.5s, ..., 13 ks. For adaptive aver-aging the value specifies the maximum measur-ing time after the detector algorithm has beenactivated. For linear averaging, the value spec-ifies the averaging time

HARMONIC DISTORTION:Simultaneous measurement of selected harmon-ics up to 20th. Total, Total Distortion and TotalHarmonic Distortion can be automatically calcu-lated from selected harmonics

DIFFERENCE FREQUENCY DISTORTION:Simultaneous measurement of selected Differ-ence Frequency products up to 9th order. TotalDistortion can be automatically calculated fromselected products

INTERMODULATION DISTORTION:Simultaneous measurement of selected Inter-modulation products up to 9th order. Total Dis-tortion can be automatically calculated fromselected products

TOTAL RMS:Measurement of broadband RMS. Includes alldistortion products and noise within the frequen-cy range of the analyzer. Specifications for thedynamic range of the input are reduced for thistype of measurement.Distortion Products and Noise:<–55 dB re full scale

12

Specifications 2012 (Version 4.0) (Cont.)

FFT Spectrum:

BASEBAND MODE

ZOOM MODE

Centre frequency:1Hz + B/2 to 40kHz – B/2where B = bandwidthAVERAGING:Complex or Power averaging from 1 to 4096averagesWEIGHTING:Hanning, Flat Top or Rectangular by Power av-eragingGENERATOR:Off, one-tone and two-toneCONDITIONING TONE:(One-tone only)Duration:0.0s to 10.0s (max. 3 decimals, rounded off tonearest 10ms value)Level:–40dB to 40dB in 0.1dB steps, re measuringtone level

TRIGGER:Free Run, External, Internal or GeneratorTrigger level:Can be selected in the range –100% to 100%of the specified input level, by internal triggerTrigger delay:

BASEBAND MODE

ZOOM MODE

External Trigger input:BNC socket on front panel

External Trigger levels:HC MOS compatible. Triggers at high levels from3.5 to 5.0V and does not trigger at low levelsfrom 0 to 1.5V

Manual Generator:

Each generator can be activated for direct man-ual control of output and input.The generators’ output frequencies and levelsare controlled by the dial on the front panel. Theoutput frequency and level as well as the inputlevel are shown on the screen

Auto Sequences:

2012 can store 5 Auto Sequences, each up to100 lines.Auto Sequences can be edited in a special menuappearing as a list containing the correspondingIEEE-488 bus commands. A “learn mode” isused to make this list by simply pushing thedesired key. When an Auto Sequence is started,the functions and parameter settings are exe-cuted in sequential order

Block Arithmetic:

Block Arithmetic functions are performed on aset of data in one of the 11 result memories(Buffer, “M 1” to “M 10”). The result of a BlockArithmetic operation is a new set of data in theresult Buffer, which can be copied to “M 1” to“M 10” at the same time

OPERATIONS:• Copying data between the 11 result memories• Weighting data with a frequency window: Han-

ning, Rectangular and Rectangular with Han-ning-taper

• Weighting data with a time window: Hanning,Rectangular and Rectangular with Hanning-taper

• Addition and Subtraction• Multiplication and Division (in the frequency

domain)• Time shift (linear phase shift in the frequency

domain) of a set of data• Change Sign (180° phase shift)• Reciprocal Value (in the frequency domain)• Absolute Value• Square and Square root of the amplitude in

the frequency domain• Exp• Ln (in the frequency domain)• Constant (sets a set of data to a constant k)• Adding poles/zeros• Editing values• Converting a set of data to another frequency

format

Special Calculation:

For use with the software extension Special Calculation Software Type 7661 See separate Product Data sheet for further details.

Disk I/O:

Built-in 31/2″ high-density floppy disk drive (720Kbyte or 1.44Mbyte formatted capacity). Thedata format is compatible with PC/MS–DOSA list of files can be shown on the screen.Data which can be read from or to the disk is:parameter setups, Auto Sequences, sets ofmeasurement data, screen pictures with meas-urement curves and user-defined text, screencopy data for printer or plotter

OPERATIONS:• Store• Recall• Delete• Protect• Unprotect• Rename• Copy• Format

Internal Memory:

A static 4Mbyte RAM memory with battery back-up is used for storing:• Program Source• Parameter Setup• 5 Auto Sequences• 11 Measurement results (Buffer and “M 1”

to “M 10")• Dual Graph setup with up to 36 curves and

two user-defined text buffersWhen switching on or resetting the 2012 withoutthe program disk, the program source, parame-ter setup, Auto Sequences, result memories andgraph setups stored in the RAM are used.Switching on or resetting with the program diskin the disk drive reads the program source fromthe disk and reset all data to factory defaults

Display:

Type:Built-in 12″ CRT colour screen, 16 colours canbe selected from a palette of 4096Resolution:640× 480 pointsFrame frequency:50Hz or 60HzLine frequency:31500HzContrast:Can be adjusted at the front panelRGB monitor:9-pin D-range female connector on the rear pan-el with RGB and sync signals

Graph:

The Graph menu on the screen is used to setup one or more (up to 36) curves in user-definedcolours, based on the data from one of the 11result memories. Curve colours, graph scaling,smoothing, grid setting and x- and y-axis param-eters are also set up in this menuFunctions implemented:• Frequency Response• 1/3-octave Response• Time Response• Response Decay• Frequency Spectrum• 1/3-octave Spectrum• Time Signal• Signal Decay• Auto Correlation• Level ResponseCoordinate:Is used to select the real coordinate to be dis-played from the complex function (if possible)• Real Part• Imaginary Part• Magnitude• Phase• Group Delay• Instantaneous Frequency

SCALING FOR SPECTRA:Amplitude, RMS, power, ASD (amplitude spec-tral density), PSD (power spectral density) orESD (energy spectral density)

Freq.Range Points Samples Time

1Hz–400Hz1Hz–400Hz1Hz– 4kHz1Hz– 4kHz1Hz–40kHz1Hz–40kHz

1600400

1600400

1600400

409610244096102440961024

4s1s

400ms100ms40ms10ms

Bandwidth Points Samples Time

1.56Hz3.12Hz6.25Hz...1600Hz

513513513...513

102410241024...1024

327.7s163.8s81.9s...

320ms

Freq.Range Time Delay

1Hz–400Hz1Hz–400Hz1Hz– 4kHz1Hz– 4kHz1Hz–40kHz1Hz–40kHz

4s1s

400ms100ms40ms10ms

− 4s to 32s− 1s to 32s

− 400ms to 3.2s− 100ms to 3.2s

− 4oms to 320ms− 10ms to 320ms

Freq.Range Time Delay

1.56Hz3.12Hz6.25Hz...1600Hz

327.7s163.8s81.9s...

320ms

− 327.7s to 10485s− 163.8s to 5242s

− 81.9s to 2621s...

− 320ms to 10.2s

13

Specifications 2012 (Version 4.0) (Cont.)

COMPLIANCE WITH STANDARDS:

CE-mark indicates compliance with: EMC Directive and Low Voltage Directive.

Safety IEC 348: Safety requirements for electronic measuring apparatus.

EMC Emission EN 50081–1: Generic emission standard. Residential, commercial and light industry.CISPR 22: Radio disturbance characteristics of information technology equipment. Class B Limits.FCC Rules, Part 15: Complies with the limits for a Class B digital device.

EMC Immunity EN 50082–1: Generic immunity standard. Residential, commercial and light industry.Note 1: The above is guaranteed using accessories listed in this Product Data sheet only.Note 2: Rf immunity implies that specifications of harmonic and spurius when using the Direct- or the Preamp. input may be deteriorated by up to 40 dB in the most sensitive range.Note 3: Esd levels of +/− 8KV or higher, imposed on the keyboard connector when connected to the 2012, could cause malfunction of the keyboard. Proper function is established by disconnecting and connecting the keyboard.

Temperature IEC 68–2–1 & IEC 68–2–2: Environmental Testing. Cold and Dry Heat.Operating Temperature: +5 to +40°C (+41 to +104°F)Storage Temperature: –25 to +70°C (–13 to +158°F)

Humidity IEC 68–2–3: Damp Heat: Operating: 30°C, 90% RH (non-condensing)Storage: 40°C, 90% RH

Mechanical Non-operating:IEC 68–2–6: Vibration: 0.3 mm, 20 m/s2, 10–500 HzIEC 68–2–27: Shock: 1000 m/s2

Screen Format:

The default screen format has a graph area onthe left-hand side of the screen and a menu onthe right-hand sideThe following screen formats can be set up inthe Screen Format menu:Graph A:Curve Only: gives a single graph area for dis-playing up to 36 curves in user-defined coloursText Only: shows a full text page for keying inuser-defined textCurve & Text: for superimposed display ofcurves and textGraph B:As Graph AGraph A & B:Is used to display a dual screen format. Theupper graph area shows the Graph A picture,the lower one Graph B.Graph Only:The Graph area (A, B or A & B) takes up thewhole screen. No menu is shown

Full TSR/SSR/FFT Setup:Parameters from Time Selective Response-,Steady State Response- or FFT Spectrum-men-us respectively, as well as parameters from Lev-el-, Input- and Output menus, are displayed intables which take up the whole screen. No menuis shownGraph and TSR/SSR/FFT Setup:Parameters from Time Selective Response-,Steady State Response- or FFT Spectrum-men-us respectively, as well as parameters from Lev-el menus are displayed on the left-hand side ofthe screen. The graph area is shifted to the right.No menu is shown

IEEE/IEC Interface:

Conforms to IEEE-488.1 and IEC 625-1 stand-ards. Any function shown on the display, exceptfunctions concerning IEEE-488 controller func-tions, can be transmitted to and from Type 2012.This includes parameter setup, result data, dis-play data and Auto Sequences (in ASCII or bi-nary format)

FUNCTIONS IMPLEMENTED:Source HandshakeSH1Acceptor HandshakeAH1TalkerT6ListenerL4Service RequestSR1Remote/LocalRL1Parallel PollPP1Device ClearDC1Device TriggerDT1ControllerC1, 2, 3, 4, 12

COMMAND SET:Standard engineering English reflecting the frontpanel and screen names. Compound headersfor read/write setup functions (refer to IEEE-488.2)CODE:ASCII (ISO 7-bit) code or binaryINTERFACE TERMINATOR:Can be specified in the Interface IEEE menu orfrom a controllerDEVICE ADDRESS:Addresses from 0 to 30 can be specified in theInterface IEEE menu

CONTROLLER FUNCTIONS:Hard copies are output to the IEEE-488 bus onlywhen Type 2012 is set up as system controlleror is the controller-in-charge.When 2012 is used as system controller it ispossible to output interface messages:

14

Universal Commands (DCL and LLO)Addressed Commands (SDC, GET and GTL)Listen Address and UNLDevice Dependent Messages in ASCII code

and to conduct a Serial Poll

RS-232-C Interface:

Screen Copy output only.Conforms with the EIA Standard RS-232-C(equivalent to CCITT V24).Coupled as a “Data Terminal Equipment” (DTE)Connector: .........................25-pin D-range maleMode of operation: ............................Full duplexNumber of data bits: ....................................7, 8Number of stop bits: ....................................1, 2Baud rates: ..................... 300, 600, 1200, 2400,............................................. 4800, 9600, 19200Parity: ...................................... None, Even, OddSynchronization method: X-on/X-off, Hardwired, Off

Power Supply:

Voltage: 100V, 115V, 127V, 200V, 220V and240V AC ±10%Frequency: 50Hz – 60Hz ±5%Power rating: approx. 150VAComplies with Safety Class II of IEC 348

General:

Safety: Complies with IEC 348 Safety Class IICabinet: Supplied as model A (metal cabinet)or C (as model A but with flanges for standard19" racks)Dimensions:Height: 310.4mm (12.2in)Width: 430mm (16.9in)Depth: 400mm (15.7in)

Weight: 32.5kg (71.6lb)HELP PAGES:Help pages are provided for all buttons, and canbe selected in English, German or FrenchKEYBOARD:A standard “QWERTY” keyboard with exchange-able keys for German and French characters isdelivered with the 2012. The 2012 is easily setup to German or French characters, at the sametime changing the language of the help pages.The keyboard connects to the front panel

SCREEN COPY:The Screen Copy function supports multi-colourpen-plotters (HPGL), matrix printers, ink-jet print-ers and laser printers can be connected to theIEEE-488 and RS-232-C outputs. By pushingthe Screen Copy button a copy of the presentscreen picture is printed or plotted. Printer driv-ers for a number of popular printers are includedin the instrument menu

REMOTE CONTROL:8-pin DIN socket on the rear panel for controllingStart, Stop, Proceed or Continuous. One pin isused to indicate “Busy“ state and one pin is usedfor user-defined indication controlled by push-keys

Specifications Accredited Calibration EK0130 to EK0132

TYPE OF CALIBRATION:

EK 0130 Standard: Certificate of Calibration and a complete testreport with all measured data

EK 0131 Pre-calibration: Consists of two standard calibrations where thefirst calibration is performed on the analyzer asit is received. The second calibration is per-formed after adjustment/repair

EK 0132 Initial: Standard calibration ordered when a factory Cer-tificate of Calibration is required with the deliveryof a new analyzer

Ordering Information

Type 2012: Audio AnalyzerIncludes the following Accessories:

Type 7661: Special Calculation Software. See separate section for description

BA 1000: Binder containing User Manuals Vols. 1, 2 and 3, (in English), Main Program Disks (in English, French and German), Familiarization Guide Disk and Application Example Disks

NP 0028: External Keyboard

SN 0187: Set of keys with French characters

SN 0188: Set of keys with German characters

2 × AO0087: BNC to BNC Coaxial Cables

AO 0158: BNT to BNT Triaxial CableJJ 0330: BNT Triaxial Connector

JP0315: BNT Triaxial PlugJP0802: 8-pin DIN plug (male)

2 × VF0007: Spare Fuses F 1.6A/250V

3 × VF0019: Spare Fuses F 3.15A/250VMains Cable

Optional Accessories

KS 0027: Set of Rack Mounting FlangesWB 1360: Remote Controlled Switchbox

Calibrations:EK 0130: StandardEK 0131: Pre-calibrationEK 0132: Initial(See separate specifications for full information)

UA 1283: Upgrade Kit

Kit for upgrading Audio Analyzer Type 2012 Ver-sion 3.0 to Version 4.0

Tests Applied:Visual inspectionDigital Self-testAnalog Self-testFrequency accuracyOutput attenuator f1: 1 kHz and 40 kHzOutput attenuator f2: 1 kHz and 40 kHzOutput Frequency Response f1: Full scale andfull scale minus 30 dBOutput Frequency Response f2: Full scale andfull scale minus 30 dBCommon Output f1+f2, f1Common Output f1+f2, f2Input Frequency responseInput attenuator: 1 kHz and 40 kHzInput amplitude linearity

Preamplifier inputPolarization voltage (outside accreditation)Certificate of Calibration:Complete test report with all measured data andmeasurement uncertainties. All measurementsare traceable to international standards. Calibra-tion fulfils ISO 9000 requirements.

15

The kit includes the following items:• Main processor board with 4 Mbyte static RAM

and battery back-up• PROM upgrade• Binder containing User Manuals Vol. 1, 2 and

3 (in English), Main Program Disks, Familiar-ization Guide Disk and Application ExampleDisks

The upgrade kit can be installed at the nearest Brüel & Kjær service office

System Configurations

LOUDSPEAKER AND MICROPHONE TESTING:Type 2669B: Microphone PreamplifierType 4191: Free-field 1/2″ MicrophoneAO 0428: Preamplifier CableWQ1105: Audio Power AmplifierAO 0027: Microphone Extension Cable

(3m)AO 0087: BNC to BNC CableUA 0801: TripodUA 0588: 1/2″ Microphone SupportUA 0610: Extension RodApplication Disks with Auto Sequences for Loudspeaker Parameter Measurements (using Laser Velocity Transducer Type 3544), Simulated Free-Field Loudspeaker Measurements and Microphone Measurements are available. These are described in separate Product Data sheets

TELEPHONE TESTING:Type 5906 : Telephone Interface (includes

IEEE–488 Interface Cable AO 0265)(National variations available)

Type 4227: Mouth SimulatorType 4602: Telephone Test HeadType 4185: Ear Simulator for Telephonometry

(including1/2″ microphone and preamplifier and built-in sound source for seal check)

3 × AO0087: BNC to BNC CableAO 0434: Dual 4 mm plug cableJP 0225: BNC socket to dual 4 mm plug PC-controlled test systems based on Type 2012are available. These systems are described inseparate Product Data sheet

HEARING AID TESTING:Type 4222: Anechoic Test ChamberType 4157 : Ear SimulatorType 2669 B: Microphone PreamplifierType 4192: 1/2″ Condenser MicrophoneWQ 1105: Audio Power AmplifierAO 0087: BNC to BNC Cable

HEADPHONE TESTINGType 4128: Head and Torso SimulatorType 4159: Left Ear SimulatorType 5935: 2-channel Microphone Power

SupplyWQ 1105: Audio Power AmplifierAO 0087: BNC to BNC CableAn Application Disk with Auto Sequences forHeadphone Measurements is available. It is de-scribed in separate Product Data sheets

Miscellaneous:

QR1102: Package of 10 31/2″ dual-sided double-density floppy disks

QR1105: Package of 10 31/2″ high-density floppy disks

Interface Cables:

AO0265: Interface Cable (2m), IEEE-488

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USES:

Automatic testing of telephones:— Handset telephones— Hands-free telephones— Loudspeaking telephones— DTMF testing

Automatic testing of transducers and other audio equipment:— Loudspeaker drive units— Complete loudspeaker systems

Automatic testing of hearing aids, headphones, microphones, hydrophones, head-sets and intercom systems

Evaluation of automotive acoustics

Preparation of report-ready documentation

FEATURES:

Calculation of Curve Average, such as sensitivity (IEC 581–7) and Loudness Rating (IEEE–269/661)

Calculation of Curve Summation, for example, weighted overall levels (Loudness Rating, CCITT Rec. P.79)

Automatic testing against absolute, floating or aligned tolerance limits

Reference cursor for reading out cursor values relative to a reference point or curve

Cursor value conversion, for example for converting sound propagation delay into path length

Max. or Min. Cursor for finding local or global maxima or minima. Calculation of pure tone frequency and level (spectrum), for example for DTMF testing. Calculation of resonance parameters (response), resonance frequency, Q-value or peak value

Various mathematical and Boolean operations on the above

All Special Calculation values can be integrated in the graph text and can be automatically updated when making new measurements

Fig.1 Report-ready documentation. 7661 has advanced facilities for integrating meas-urement values and graph text with measurement curves on the screen. You can set upany number of curve references in a graph text. Values are automatically updated whennew values are measured or calculated. Data can be exported to a computer spreadsheet

Special Calculation Software Type7661 is a software extension for theAudio Analyzer Type 2012. The mainpurpose of Type 7661 is to increase theanalyzer’s options for making automat-ed measurements, and extracting andpresenting information from the meas-urements.

Type 7661 is suitable for quality con-trol purposes where the result of ameasurement must be reduced to apassed/failed indication and where theanalyzer must perform certain opera-tions dependent on the result.

Type 7661 is equally suited for gen-eral measurement purposes where ameasurement result must be expressedas a single number, or a few numbers.

The facilities of Type 7661 are con-tained in the Special Calculationmenu. Access to this menu requires aspecial “key” which must be installedin the 2012.

Special Calculation Software — Type 7661

Fig.2 The Curve Summation facility can be used for calculating, for example, LoudnessRating for telephones. The curve as well as the calculated values can be tested againsttolerance limits

Introduction

Test and Design ParametersMeasurement curves are invaluablefor development purposes, but theyusually contain a lot more informa-tion than is actually needed. Formost practical purposes, the final re-sult that is needed from a measure-ment is not a curve but a singlevalue. This is particularly true forquality control purposes where aproduct such as a loudspeaker or atelephone, must pass certain qualitycriteria to decide whether or not theunit is rejected. The result of such ameasurement must therefore be re-duced to a passed/failed indication.

For a number of general measure-ments, it is also necessary to expressa measurement as a single value.This is the case with measurementsthat comply with certain standards,e.g., Loudness Rating, Loudspeakersensitivity or hearing aid gain (HFA).

For practical purposes, where theanalyzer must perform certain oper-ations automatically depending onthe outcome of a measurement, it isalso necessary to reduce a measure-ment to a single value.

Report-ready DocumentationType 7661 enables the analyzer tocalculate a single value and read itout in the Special Calculation cursorfield. Up to ten single values (curvevalues) can be stored with eachcurve, and each curve value can con-sist of a name, a value, a unit and atest result. The curve values can befurther processed by using mathe-matical operations, and they can betested against tolerance limits. In ad-dition, up to ten text strings can bestored with each curve. The textstrings can be used for storing infor-mation about the operator, a serialnumber, the date and/or time of themeasurement. Finally, the curve val-ues and text strings can be integratedinto a graph text, which is automat-ically updated when new measure-ments are made or new values arecalculated. Report-ready documenta-tion can then be printed or plottedout directly from the analyzer. Alter-natively, an ASCII output can be pro-duced for export to a computerspreadsheet.

Curve Operations

The curve operations Summation, Av-erage and Tolerance are used to cal-

culate a single value from a measure-ment curve.

You can store up to four differentparameter set-ups for each of thecurve operations. This means thatyou can easily change between, forexample, Loudness Rating accordingto IEEE-269, IEEE-661 or CCITTRec. P.79.

Curve SummationThis is used for calculating a weight-ed total sum of the values in thecurve, for example Loudness Ratingaccording to CCITT Rec. P.79.Fig.13shows a telephone measure-ment with tolerance limits and Loud-ness Rating.

Curve AverageThis is used for calculating a weight-ed average of the values in a curve,such as Loudness Rating according toIEEE-269/661, Loudspeaker Sensi-tivity according to IEC 581-7 or HFAgain (hearing aid gain) according toANSI S 3.22.

Curve ToleranceGenerates a Pass/Fail message andcalculates the margin (the least dis-tance) from a curve to one or twotolerance limits. The following typesof tolerance limits are available:

Absolute — the curve is testedaginst fixed tolerance limits

Floating — the curve is positionedrelative to the tolerance limits (or

vice versa) in such a way that theminimum distance from the curveto the upper and lower tolerancelimits is exactly the same

Aligned — the curve is positionedrelative to the tolerance limits (orvice versa) by a specified offset ata user-defined reference point.

Special Cursors

The cursor operations Reference,Convert, Max. and Min. are used tocalculate one or more curve valuesbased on the current cursor position.

You can store up to four differentparameter set-ups for each of the spe-cial cursors.

Reference CursorCan be used for reading out the dif-ference between the actual cursor po-sition and a reference value. Thereference value can be another pointon the same curve, or a point on an-other curve.

Convert CursorCalculates a linear, logarithmic, re-ciprocal or exponential conversion ofthe cursor coordinates. It can be usedto read out the difference in distancebetween different signal paths, basedon the delay and a specified propaga-tion speed, or to read out distortionin percentage instead of dB.

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Fig.3 The Max. Cursor can be used to automatically calculate the Q-value for a loud-speaker

Fig.4 Overview of the data flow and the View function for reading out results for thecurve operations, cursor operations and value operations

View:

Save Selected

Value

Only CursorOperation

V Buffer

SpecialCalculationCursor read

out

921707e

Special CalculationCursor Field

Value Data(V 1...V 10)

String Data(S 1...S 10)

Curve Data(X,Y)

Curve1 – 36

Only ValueOperation

Opr: Curve,Cursor,Value

Curve References

This feature allows all curve valuesand text strings to be integrated intoa graph text, anywhere in the screenpicture. These are automatically up-dated if new values are measured orcalculated.

Installing 7661For maximum compatibility, there isonly one version of the 2012 mainprogram which includes the Type7661. To make use of the facilities ofType 7661 which are contained in theSpecial Calculation menu, a hard-ware “key” must be installed in the2012.

Max. and Min. CursorsFor locating a local or global mini-mum or maximum and positioningthe cursor on that point. Further-more, for frequency responses, theresonance frequency, level and quali-ty factor (Q) can be calculated. Forfrequency spectra the pure tone fre-quency and level can be calculated.Fig.3 illustrates a data sheet for aloudspeaker with some of the basicdriver parameters.

Value Operations

A number of mathematical opera-tions can be performed on the curvevalues. The results can be testedagainst tolerance limits. The opera-tions are:

Addition Subtraction Multiplication Division Square Square root Sign Change Reciprocal Absolute Ln Logarithm Exponent 10^ Maximum Minimum Test — for testing a value against

a reference interval AND OR NOT Copy — for transferring values be-

tween different memories

Tolerance LimitsAll curve values can be tested againstboth upper and lower limits and as aresult will produce a passed or failedindication. The logical (Boolean) op-erators listed above are used for var-ious operations on test results, e.g.,if a test object must pass a numberof tests before it is accepted, the“AND” operator can be used to checkif all tests are passed.

Edit OperationsVarious editing facilities are availa-ble for changing the name, numericalvalue, unit and passed/failed infor-mation of a test result. The currentdate and time from the 2012’s inter-nal clock can also be stored with eachcurve.

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19

Specifications 7661

Ordering InformationOrdering of Type 2012 includes the Type 7661Software. Type 2012 A versions 3 and 4 can beupgraded to Type 2012 by ordering and installingType 7661

The Type 7661 software is supplied on the same31/2" 1.44Mbyte disk as the main program. Theuser information is included in the Manualssupplied with the analyzer. When you order Type7661 you receive a Protection Key VP 5348 and

an Installation Guide BI 0774 that tells you howto install the Protection Key in the 2012 Analyzer.If you encounter any problems you shouldcontact your local Brüel&Kjær representative.

Curve Operations

CURVE SUMMATION:For calculating a total sum of the values in acurve according to:

A weighting curve can be specified. The sum-mation can be performed over all the values inthe measurement curve, the weighting curve orin a specified interval. The values can be useddirectly or can be raised to any power. The cal-culated results can be tested against upper, low-er or both limits.

CURVE AVERAGE:For calculating an average of the values in acurve according to:

Otherwise as described for Curve Summation.

CURVE TOLERANCE:For calculating the margin (the least distance)from a curve to one or two tolerance limits.

• Absolute: Both the curve and tolerance limitsare fixed

• Floating: Makes a best fit for the curve be-tween the tolerance limits

• Aligned: Positions the curve relative to thetolerance limits (or vice versa) by a specifiedoffset at a user-defined reference point.

Cursor Operations

CURSOR REF:Reads out the difference between a referenceand the current cursor position. Both X-Y- or Z-values are read out.

CURSOR CONVERT:Calculates and reads out a linear, logarithmic,reciprocal or exponential conversion of the cur-sor coordinates. X, Y or Z-values can be con-verted.

CURSOR MAX:Finds a local or global maximum for a curve andpositions the cursor on that point. The maximumcan be found within a specified absolute interval,or within a standardized octave interval.From the magnitude of a frequency response,the resonance frequency, the level and the qual-ity factor (Q) can be calculated. From the mag-nitude of a frequency spectrum, the pure tonefrequency and level can be calculated.

CURSOR MIN:Finds a local or global minimum for a curve andpositions the cursor on that point. The minimumcan be found within a specified absolute interval,or within a standardized octave interval.For magnitude of a frequency response, the res-onance frequency, the level and the quality factor(Q) can be calculated.

All calculated cursor values can be testedagainst upper and/or lower limits.

Value Operations

The following mathematical operations can beperformed on curve values:

• Addition• Subtraction• Multiplication• Division• Square• Square root• Sign Change• Reciprocal• Absolute• Ln• Logarithm• Exponent• 10^• Maximum

• Minimum• Test• AND• OR• NOT• Copy

The Boolean operators can only be used withthe test results (passed/failed). “Passed” is rep-resented by “true” and “failed” by “false”. Test isused for testing a value against a reference in-terval. Copy is used for transferring values be-tween different memories.

EDIT FACILITIES:For editing the name, numerical value, unit andtest result of a curve value. Text strings can alsobe edited.

Storage

Up to ten curve values consisting of a name,numerical value, unit and test result can bestored with each curve. All results are temporar-ily stored in a Special Calculation Buffer called“Vbuffer” and can be stored in the curve valuememories “V1, ...,V10”.Up to ten text strings can be stored with eachcurve. Text strings are stored in memories S1, ...,S10, and each text string can consist of maxi-mum 12 characters. The date and time can betransferred from the 2012’s internal clock to atext string.Four different parameter set-ups can be storedfor each of the curve operations and each of thespecial cursors.

Curve References

Any number of curve values and text strings canbe integrated in a graph text. The curve refer-ence values are automatically updated if newvalues are measured or calculated.

For full specifications of Type 2012, see the sep-arate Product Data BP 0995 and BP 1302.

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Brüel&Kjær reserves the right to change specifications and accessories without notice

Brüel & Kjær B K

BP 1503 – 12 95/12

WORLD HEADQUARTERS: DK-2850 Nærum • Denmark • Telephone: +4542800500 •Telex: 37316 bruka dk • Fax: +4542801405 • e-mail: info@bk.dk