Audio Measurement and Analysis Software

 News

March, 10, 2014.

ARTA service release version 1.8.1 is published (see download section).

Changes from version 1.8.0 are:

- In ARTA corrected registry saving of data for 1/3 octave band measurements.
- In ARTA corrected determination of bitmap copy size in Directivity View.
- LIMP now does check of frequency range for LSE optimization in TSP estimation.
(optimization needs measurement to 20kHz or at least to 100*fs)
- STEPS now has fully compatible calibration data file (*.cal) with ARTA calibration file
(the difference was in opposite sign of LR channel difference dB value).
- STEPS enables measurement of distortion harmonics D6+, that were unintentionally switched off in version 1.8.0.

December 18, 2013.

ARTA version 1.8.0 is published (see download section).

New features are:

- ARTA has enhanced view of directivity pattern with new "filled contour plot"
- Reference angle for directivity normalization is now user defined
- ASIO driver recognized true 24 bit format of I/O transfer
- ASIO response has been improved
- Calibration procedure has selectable sampling rate: 44100 and 48000 Hz
- Added Phase intercept distortion in ARTA smoothed frequency response window
- Added overlay in ARTA Step response window
- ARTA saves number of averages in IR measurement setup
- Mic. freq. compensation accept only raising frequency points
- New Tool in ARTA: 1/3 octave SPL and loudness time record history
- LIMP has subtract from overlay command (good for removing influence cable resistance)
- LIMP has cable serial impedance compensation
- LIMP has new L3R lossy inductance model of loudspeaker voice coil impedance
- LIMP has better (nonlinear LSE) optimization of TSP estimation
- LIMP has ability to show several target curves,
- LIMP can generate special target curve by pressing F3 in main window - loudspeaker impedance calculated from TSP
- STEPS has corrected *.csv export
- STEPS has new type of measurement: Loudspeaker Maximum SPL vs. Distortion

On support page there are new tutorials for ARTA, STEPS and LIMP in german language, new case study on loudspeaker design, and link to paper entitled Estimation of Loudspeaker Driver Parameters, which explains numerical methods used in LIMP.

November 14, 2011.

New application note  "AP-8 Repetitive measurements with script language AutoIT" is published. See link on  support page.

ARTA service release version 1.7.1 is published (see download section).

Following bugs are corrected:

- Substract from overloay enabled in Fr2 mode
- Creation of directivity data from files that resides on other disks
- Report for minimum value of octave RC curve (RC < 25) corrected (from RC < 15)
- Averaging in Octave and Third octave Level measurement correctly applied to wideband level L
 

December 18, 2010.

ARTA version 1.7.0 is published (see download section).

New features, implemented in program ARTA, are:

- ASIO soundcard interface is implemented in ARTA, STEPS and LIMP programs.
- New menu in Imp window: Record -> Signal Time Record opens transient recorder with added generator.
- Generator in transient recorder generates sine burst and pulse signals.
- Periodic square and triangle signals are added to ARTA generator.
- Generator has new multitone signal (square + sine) for measuring TIM (DIM).
- In Copy bitmap dialog, user defined text can be saved for next opening of the dialog.
- Added more MLSSA files import types (impulse and transient response).
- Directivity curves smoothing improved at highest frequency.
- Microphone compensation applied only in the range that is defined in mic. fr. response.
- Downsampling (menu Edit->Downsample in Imp window) enabled analysis of CSD in low freq. range.
- Acoustical parameters now calculated only for available range of frequencies.
- Better ISO3382 compatibility in the estimation of reverberation time and noise reduction.
- Improved estimation of very small reverberation time.
- Implemented Scaling of acoustical model response (menu 'Edit->Scale acoustical model' in Imp window).
- New Imp menu command added (Edit->Truncate to [cursor, marker]).
- Calibration procedure is now slightly simpler (calibrated output voltage is automatically entered as input voltage).
- Overlay plotting is enabled in Step, Dft and IR Envelope windows.
- Impedance curve overlay can be shown in FR magnitude plots of ARTA and STEPS.
- Now all FR and spectrum graphs can have tick marks and denser grid (Menu Edit->Colors and grid style) .
- Thick line option is enabled in all windows.
- STEPS now optionally mutes transients after sine cut-off (but, measurement time larger 50%).

Bugs solved:

- Microphone calibration update is enabled from SPL & Octave band windows.
- Mlssa export does not make normalization to 1.
- Solved bug with MLS and other nonpower of 2 length IRs in IACC measurement.
- STEPS now has correct frequency step in 1/48 octave mode.

 

Note: After install over old version, please click on menu 'Edit->Colors and grid style', then in dialog 'Graph Colors and Grid Setup' click on button 'Default'. Repeat previous procedure for white background.

New version of tutorial in German language is on support page.

January 3, 2009.

ARTA version 1.6.1 is published (see download section).

New features, implemented in program ARTA, are:
- Saves background color in registry.
- IR measurement dialog gets check box 'Close after recording' to close itself after recording.
- Alt-R-R-R starts and closes measurement in PIR window.
- Alt-R-R starts and closes measurement of PIR in FR window.
- Envelope and Step response windows remember the zoom ratio.
- Shorcut keys for Cursor movement: Home (to 300 sample) , Del (to 0 sample).
- Shorcut keys for Cursor movement are: Crtl+Home (to 300) , Ctrl+Del (to 0), Ctrl+Ins (to cursor).
- Signal recorder can do a triggered time averaging.
- Spectrum estimation of gated recorded signal now gives an averaged spectrum of ovelapped segments.

Foollowing bugs are removed:
- Contour plot appears after reopening the directivity window.
- In correlation graph the background color now trace the global backgound color.
- Spectrum overlay does not depend on type of window (if made in PSD mode must be used in that mode).

December 6, 2009.

ARTA version 1.6.0 is published (see download section).

New features, implemented in program ARTA, are:
- Signal recorder now function as storage scope with triggering capabilities on both channels, with predelay and postdelay.
- For recorded signal the gated spectrum analysis and Short-Time Fourier waterfall plot are possible.
- Import from wav and ascii files can be analysed as IR or signal time record.
- A contour plot added for the presentation of directivity patterns.
- In reveberation window, the 95% cut of tail enabled.
- In all time windows 8 x zoom enabled, with zoom report on graphs.
- A button is added to Imp window control bar, for setting cursor on position of max amplitude.
- New tool: Two-channel voltage level meter and 1/3 oct. analyser.
- Enhanced FR target filter generation.
- Difference mode - in Fr1, Fr2, Spa - shows difference of Magnitude and overlay levels.

Following bugs are removed:
- Arta 'Load target' command - accept files with arbitrary number of points (removed hidden restriction on 720 points)
- Arta peak meter in SPL windows is tracking the peak in every recorded blocks
- Limp correctly reports Le.
- Steps correctly reports X-axis values in Distortion vs. excitation plot.

April, 5, 2009.

ARTA version 1.5.0 is published (see download section).

New features, implemented in program ARTA, are:
- Recording a PIR with an external pulse excitation,
- Automatic ISO3382 parameters estimation,
- ISO3382 parameters estimation in 1/3 octave bands with graphical and table presentation,
- Delay for the phase adjustment possible in FR windows,
- 1/1 octave SPL meter with a Noise rating (NR,NC, PNC, RC, NCB),
- 1/3 octave SPL meter, with specific loudness, loudness in Sone and loudness level in Phon reports,
- Saving/loading all overlays in a Smoothed FR window,
- Estimation of acoustical spatial parameters: IACC, LF and LFC,
- Exports in wav file, also in floating point format.

Two bugs solved:
- Overlay properly refreshed after recording in PIR window.
- Directivity pattern constructs correctly from gated responses

In program STEP a switch is added to select automatic setup of overlay.

July, 20, 2008.
ARTA service release version 1.4.2 is published (see download section).
Just a few bugs have been removed:
- In ARTA, the SPL measurement now correctly deals with input channel clipping condition.
- Soundcard playback method has been redesigned to better handle the stop command.
- In STEPS and LIMP the generation of stepped sine on frequencies bellow 20 Hz has been improved.
 

April, 24, 2008.
ARTA version 1.4.1 is published (see download section).
Changes from version 1.4.0 are:
- ARTA version 1.4.0 is not compatible with a Windows 98/ME/NT.
  This service release ver. 1.4.1 re-establishes compatibility with these operating systems.
   In future releases these operating systems might not be supported.
- A bug in calculation of beam-width angle in Directivity pattern is corrected.

 

April, 20, 2008.
ARTA version 1.4.0 is published (see download section).
Changes from version 1.3.0 are:
- The dual-gated frequency response measurement is implemented.
- Automatic delay finder using cross-correlation (in FR2window).
- Enabled coherence + phase plot in smoothed and unsmoothed FR2 graphs.
- More precise ASCII exported values.
- Generator signal can be saved in .wav files.
- The last PIR excitation signal type is saved in registry.
- Group delay auto-ranging improved.
- Sine generator reports soundcard output RMS voltage.
- Added keyboard shortcuts for moving marker (shift-> , shift <-).
- Main program window size and position memorized between program executions.
- Added grid in spectrograms.
- PIR graph can have one overlay curve.
- Integrating SPL meter with 24 hours data logging possibility is implemented.
- In program STEPS a method for the measurement of the loudspeaker voice coil peak displacement is implemented.
- Improved is a work with soundcards EMU 0404USB and Duran Audio D-Audio USB

On support page a link is added to new application note: "AP7 - Estimation of Linear Displacement with STEPS".

 

October, 26, 2007.
Links to interesting papers added on support page.

June, 29, 2007.
ARTA version 1.3.0 is published (see download section).   Changes from version 1.2.1 are:
- The Farina method for simultaneous measurements of frequency response and harmonic distortion is implemented (see ARTA manual section 6.1.8).
- Burst decay envelope graphs are new tools for analysis of resonances and reflections (see ARTA manual section 6.5)
- Data export in CSV (Excel) formatted files is implemented in ARTA, LIMP and STEPS.
- In STEPS two methods are implemented for stepped amplitude testing (linearity test and distortion vs. sine amplitude).
- In ARTA the  group delay is calculated by using the user entered phase delay (as in phase calculation).
- In ARTA microphone frequency response compensation can be applied in  CSD and Burst decay plots.
- In ARTA the generator volume control for periodic noise now also controls the output level of the continuous noise.
- In STEPS minimum measurement transient time is changed from 10ms set to 20ms.
- In ARTA a few small bugs corrected:
    - corrected signal window labeling (Kaiser7) in spectrum bitmap copy
    - corrected DI report in polar plot for full space
    - corrected file name saving in directivity view

March, 4, 2007.
ARTA service release version 1.2.1 is published (see download section).

Following bugs were corrected:
- In the STEPS measurement window; the bottom label for THD was showing the value of the second harmonic distortion.
- In the STEPS distortion window; the overlay D6+ check box was not correctly switched.
- In the ARTA Smoothed FR window; menu commands for minimum and excess phase were not  handled correctly.
- In the ARTA Spectrum Analysis window, label "1/12 octave" in some cases was shown as "1/11 octave".

To install the version 1.2.1 it is not necessary to uninstall the version 1.2.0.
And one good news: ARTA is ready for the Windows VISTA (32-bit editions).

February, 5, 2007.

ARTA version 1.2.0  is published (see download section). Changes from version 1.1.1 are:
- The swept-sine measurement timing optimized for faster measurements.
- 192kHz sampling rate enabled.
- Excess phase and excess group delay graphs added in Smoothed FR window.
- Corrected ASCII file export of the step response.
- Maximum impulse response sequence length is 256k (for large reverberation time measurements).
- Reference point for single channel PIR changed to the first sample that is 20dB below the maximum value.
- New method for intermodulation distortion report (SMPTE, CCIF, DIN, IEC 60268-5).
- More versatile THD report.
- Better control of graph setup in FR analysis windows.
- Button for top scrolling “moves graph” up and down (before, it “moved” top graph margin).
- Gate time can be shown as equivalent sound wave propagation distance in cm.
- CSD can be shown as sonogram.
- CSD dynamic range can be dynamically updated.
- Directivity pattern can be shown with waterfall graph, sonogram and polar diagram.
- Waterfalls and sonograms can be shown as a contoured colored graph.
- Polar diagram shows Directivity Factor Q, Directivity index DI and Beam width angle.
- Reverberation time can be estimated in octave bands 62.5, 125,.. , 8000Hz.
- Output volume for multisine to -50dB.
- LIMP now estimates complex voice coil inductance as Le in series with L2||R2.
- STEPS analyses 2nd, 3rd, 4th, 5th and 6th+higher harmonics.
- Bugs concerning overlay management are corrected.
- STEPS can measures in 1/6-octave steps (added for faster measurements).

Note 1
: Minimum memory requirement for the Window XP is raised to 256k as ARTA 1.2 uses slightly more memory resources than earlier versions.

Note 2: The Directivity pattern tool needs lot of file manipulations, so it can be used only in registered version.

The User Manual and new application note AN6-Directivity und Polar (in German, thanks to Dr. Weber) shows use of this tool. You can load example of directivity pattern file from ArtaSoftware\example directory.

Note 3: If you have ARTA version <= 1.1.0 , please unistall the ARTA software before making the installation of version 1.2.0.

November, 01, 2006.
Spanish translation of the ARTA manual is published on support page.

October, 23, 2006.
Version 2 of the Tutorial in German language published on support page.

September, 23, 2006.
Spanish translation of LIMP and STEPS manuals is published on support page.

September, 14, 2006.
ARTA version 1.1.1  is published
(see download section). Changes from version 1.1.0 are:
1) FFT 64-bit processing is now standard.
2) New window - Kaiser7 - implemented for for hi-resolution digital signal analysis.
3) Properly initiated user defined two-sine mode from registry.
4) Faster refreshing of a graph screen in dialog boxes.
5) Group delay vertical labelling is changed.
6) Jitter test signal is implemented in Spectrum analyzer generator.
7) In STEPS, after the calibration data are properly "accepted" as souncard device calibrationa data.

Note: as there is no ARTA64.exe in setup files, please uninstall old ARTA version before setup of ver. 1.1.1.

August, 26, 2006.
A bug reported in STEPS: After I/O calibration, values in Audio Device Setup Dialog are not refreshed as in ARTA. This bug will be corrected in the next release. In the meantime, please enter calibration values in Audio Device Setup Dialog manually.

August, 21, 2006.
ARTA version 1.1.0 is published (see download section). Changes from version 1.0.3b are:
1) New overlay manager in ARTA and STEPS enables advanced operations with overlay list:
-   Overlays gets name of current pir file
-   Overlay name and color can be edited (by double clicking to overlay list item)
-   Overlays can be visible or invisible (by clicking to overlay list item check box)
-   After commands: "Edit->Subtract from overlay" and "Edit->Subtract overlay", the overlay is not deleted, instead it becomes invisible.

2)  Screen bitmap copying is greatly enhanced:
-   Now you can copy full window and graph window.
-   Copying graph bitmap can be done with user defined size and labeling.

3) New shortcuts key available:
-   Ctrl-A sets overlay from current curve (in all windows)
-   Ctrl-M opens overlay manager (in Smoothed FR window and in STEPS window)
-   Ctrl-C gets dialog with user defined options for copying graph bitmap to clipboard
-   Ctrl-P copy full window as bitmap to clipboard
-   Ctrl-B switch B/W background color

4) New command buttons added in Frequency response windows. Twice pressing Alt+R repeat last measurement.
5) BUG removed: target overlay has correct phase response.
6)Target filter response overlays now enabled in Fr2 and Fr2 window.
7) Enhanced graph presentation with frequency axis labeling: 100,200,500, 1k,2k,.., enlarged fonts, more overlay colors..
8) BUG removed: In LIMP stepped sine mode 1/24 oct. frequency step enabled.
9) A diffraction step equalizer for rectangular baffle added.

August, 14, 2006.

Please note an update in Support section: Angel Fdez.-Escalante Bárcena has contributed the spanish translation of Application Notes.

August, 03, 2006.
Please note an update in download section:

- Those who downloaded ARTA install file 'ArtaSetup103.exe' with designated date 03.08.2006  should uninstall the ARTA  and download new install file 'ArtaSetup103b.exe'. The "wrong" install file existed on download server just few hours (from 1am to 1pm CE time on 03.08.2006). It was uploaded over regular version 1.0.3, by mistake, from a development version that has wrong sine generation algorithm.

- Please note that install of version 1.0.3b demands full uninstall of version 1.0.3 (
with Control Panel - Add Remove Program). Release 1.0.3b has original sine generation algorithm and few corrections in User Manual added.
 

August, 02, 2006.
Application note 'ARTA Chamber for the Lower End Microphone Calibration'' published on Support page

July, 31, 2006.
Application notes 'Why 64-Bit Processing' and 'Loudspeaker free-field response' published on Support page.


July, 24, 2006.

ARTA service release 1.03. is available in
download section.

ARTA change-log: from ver. 1.0.1 to version 1.0.3

1) Generator dihter value was not properly saved and retrieved from the registry. Now this is corrected.

2) When loading new .mic file in Frequency response compensation dialog box, spline interpolated graph was not properly refreashed,
although it was correctly processed in the rest of program. Now this is corrected.

3) In ARTA version 1.0.0PR scaling of the frequency response in single and dual channel modes included power amplifier gain. It was assumed that user should enter the value 1 for power amplifier gain in a Dual channel setup. In version 1.0.1 this scaling was removed in a Dual channel Fourier analyzer mode but not in the impulse response window. This inconsistency was not documented and it made confusion for some users.
From this version in all dual channel measurement modes the power amplifier gain is not used in response scaling. Now it is assumed that, in dual channel mode, output response of the power amplifier is always measured with some probe (i.e. ARTA Measurement box).

4)The dB-scaling of the y-axis was correct, but sometimes "a bit strange":
    0 ... -16 ... -32 ... ... ... -160
    0 ... -17 ... -34 ... ... ... -170
    >>  0 ... -180 is missing, now added
   0 ... -19 ... -38 ... ... ... -190

5) Some soundcards generate large distortions when the sine signal generator output volume is set to 0dB (FS) and dihtering is included. This is corrected, but generally it is best not to use the volume level 0dB, as most AD converter gives a bad response at levels close to 0dB(FS).

6) Some error messages are rewritten.

7) In a Smoothed FR window, the command 'Power average overlays' is now replaced with command 'Power average with overlays', which means that active curve is also used in averaging. Now user can choose: Power averaging with overlays can be done with or without erasing overlays.

8) Linear averaging (or peak hold) has to stop after the predefined number of spectra, but Exponential averaging, however, should not stop. This is corrected.

9) Now fft-length and type of gate-window (from Impulse response analysis) are being saved in registry

10) Now Arta can import 24-bit .wav files (the minimal .wav length is 64 samples)

11) The name of the imported .tim and .wav file is retained, for faster save operation

12) In all graphs, grid lines can be drawn with a dotted style. The dotted style option can be chosen in the Color setup dialog

13) A more natural linear frequency axis labeling is applied.

14) For all graphs, frequency axis margins are changed to: 0.1Hz-100000Hz

15) Now THD lower than 0.0001% can be reported (for testing AES/SPDIF professional transmission)

16) New menu 'Overlay' in Fr2, Fr1 and Spa mode is introduced, to get same user interface as in Steps and Limp

17) New menu in Fr1 and Fr2 window:
    'File->Save as PIR' - transforms current frequency response to impulse response and saves it as current .PIR file

18) New menus in Smoothed and DFT Frequency response windows:
    'File->Repeat PIR measurement'  - opens dialog for PIR measurement. After PIR measurement, the frequency response is calculated using current PIR cursor and marker position.
    'File->Save PIR as..' - saves last measured or loaded PIR

19) New menu command in Smoothed FR window
    'LF diffraction scaling'  - enables loudspeaker baffle step equalization.

20) An experimental  version of ARTA named ARTA64 is implemented with 64-bit FFT processing (at price of extra 1MB of memory and slightly slower execution)  Who need this? Good for testing super audio cards AES/SPIDF I/O that have THD+N < -110dB.
 


May, 4, 2006.
An ARTA tutorial in German language published on Support page

April, 26, 2006.
Started licence key ordering using Share*It

April, 24, 2006.
First release version of  ARTA ready for download

April 14, 2006.
New application note on Support page: AP2 - RLC Measurement with Limp

April, 11, 2006.
Started Support page with application note : AP1 - ARTA Measuring Box (german version also available)

April, 2, 2006.

Announcement of the first public release

It was announced that the "release" version of ARTA software will be published in February or March 2006. In the meantime there was a high activity at audio Forums in evaluating ARTA. ARTA has got good scores as useful and stable program with only a few  minor bugs detected. In hundreds of discussions at the Visaton forum and the Hi-Fi Forum,  as well as in Magazines Klang+Ton and HiFi Selbstbau, there were a lot of suggestions to improve the ARTA, especially targeted to loudspeaker development.

I have accepted most of these suggestions, and implemented them in ARTA, LIMP, and STEPS. Here is the list of changes and improvements:

ARTA change-log: from ver. 1.0.0PR to version 1.0.1

1) Cursor position remembered between recording sessions.
2) Cursor position in single channel mode set to position 300 for all excitation signals.
3) Better viewport to screen plot, with font size adaptation.
4) Changed color setup, to include subgrid color and colored overlays. Added color editor for BW mode.
5) Add menu and Dialog for Frequency response compensation (it is computed from loaded text file with extension .mic that contains mic. FR). Now user can use the calibration curve of his microphone, or test the RIAA curve.
6) Icons and menus for audio devices and FR compensation get checked status. This better shows when mic. and FR compensation are used.
7) Full measurement setup, and plot colors are saved in registry (but not graph margins).
8) Different signal generator setups are for spectrum and frequency response modes.
9) Export of PIR in Wav, ASCII .txt and MLSA .txt format (wav export is normalized to maximum value of 32000 in 16-bit mono PCM format).
10) Export of plain FRD, but only in FR window (and only in magnitude-phase plot).
11) A bug fixed: Change of Center time (TS) report. Now the TS report exclude time interval before the start of the impulse response.
12) Changed position of some icons to more natural position.
13) Enlarged output of sine sweep generator for 3dB.  This makes the sweep best for measurement without averaging
(but only in environment with low level of impulsivee noise).
14) Now user can enter, save and preview information about .pir file -menu File->Info.
15) Import of impulse response is possible  from 16-bit .WAV files and MLSSA .TIM files.
16) Added new control bar in all FR windows for easy setup of graph margins.
17) Plot can be done with thick lines (in smoothed FR window).
18) Now user can make power averaging of overlays (usually used for the estimation of room averaged response) - added  Menu Edit->Power Average in Smoothed FR window.
19) User can generate overlays with optimal crossover target filter response  (FR - Menu Overlay->Generate target response). Overlays can be erased a) all or b) last entered.
20) Added the Export of Room Parameters in Excel .CVS format.
21) Added Overlay in Spectrum and Fourier analyzer windows.
22)  Added menu for merge smoothed FR wit overlays (even gated ones).
23) Octave bar top drawn with thick pen.
24) Time record export in second-amplitude.
25) Different colors used for gated and ungated part of impulse response.
26) The same smoothing algorithms is applied in all frequency response windows.

 

STEPS change-log:  from ver. 1.0.0PR  to version 1.0.1

1) Colored overlays  as in ARTA for color and BW mode.
2) Mic. frequency response compensation as in ARTA.
3) Added the Control bar with buttons for graph margins setup, as in ARTA
4) Added the Control bar for quick measurement setup
5) Shows and measure harmonics: 1st, 2nd, 3rd, 4th+ (sum of 4th..12th), and THD (from sum of 2..12th harmonics)
6) Thick/thin pen, larger font and better screen output.
7) Two measurement mode enabled: Frequency response (2ch) and Absolute level (1ch) modes. Added peak-meter in the measurement setup, for testing of input levels.
8) Export different reports for distortions and frequency response.
9) If magnitude is being scaled, the same optionally can be  applied to distortion level.
10) Export in the plain .FRD format for import to calsod, excel, ...
11) Separate log-log plot of percentage distortions (can choose one overlay for distortion).
12) File content can contain user editable text (menu File->Info).
13) Added peak level meter in measurement setup.
14) Shows one overlay in distortion plot.

 

LIMP change-log:  from ver. 1.0.0PR  to version 1.0.1

1) A bug fixed: bottom graph margin can be any value
2) Added Control toolbars similar to ARTA FR toolbar
3) Now LIMP has two measurement modes: FFT mode with pink noise excitation and Stepped Sine mode.
The Stepped Sine Mode works as in STEPS. It gives high measurement S/N (at least 30dB better than FFT mode). This mode enable measurement with high value of reference resistor (i.e. 600 ohm). It means that impedance measurement can be done using excitation from souncard output (don't need power amplifier as in FFT mode).
4) A better noise reduction algorithm is applied at higher frequencies for pink noise excitation.
5) File content can contain user editable text (menu File->Info).
6) File export in in ASCII  ZMA format.
7) Resolution for pink noise excitation fixed approximately to 1/48 octave
8) Resolution for stepped sine is 1/24 or 1/48 - octave.
9) Added dialog bar for graph control as in ARTA.
10) Colors can be user defined in BW mode.
11) Better algorithm, for finding maximum of impedance, applied.