IJData: Products: LspCAD
The numbers in the fields above denote the date the document was updated,
for instance 050111 is equal to Jan 11 2005.

Many thanks to Angel Fdez.-Escalante B rcena for the manuals/tutorial in Spanish and Roland Schirmer for the tutorial in German

LspCAD 6 installer
Get the full installer here.
This installer does in most cases not contain the latest build of LspCAD 6. Get the latest build below.

Latest build of LspCAD 6
Download and unzip the file, drop the contents in the folder for LspCAD 6 in your PC.
  Note that this is is only the latest build of LspCAD, you need to have LspCAD installed from the CD before.

Build history
LspCAD 6.65 (2022-12-27)
+ KHF tool did not update correctly when number of data points was changed
+ Added *.frd and *.zma filters for driver unit data

LspCAD 6.65 (2022-11-26)
+ G(s) G(z) filter component, added pass-band equalization feature for Digital FIR filter

LspCAD 6.64 (2021-12-11)
+ Connector component problem fixed
+ Additional checks to avoid Log10 SING error
+ Excess delay compensation option added for emulator, time domain and phase/group delay
+ Frequency steps can be Log, Lin or Log-Lin
+ 1000 steps selection did not stick properly when settings dialog closed and reopened

LspCAD 6.63 (2020-11-07)
+ Log option in general settings allows to use linear frequency steps
  when checkbox unticked, for the cases where it is desired to export
  in a linear frequency domain
+ Summary property Qp for 2nd order HP equalization not presented correctly
  the component values have always been correct though
+ Impulse response calculation modified with window based
  frequency reponse limited (0.9*fs/2) impulses for more accurate
  and aliasing free reponses

LspCAD 6.61 (2020-05-01)
+ Max number of plot points increased to 1000
+ Disabled memory of graph and schematic window location
  as it can cause problems with multiple screens
+ Solved problem with non-causal time domain response that caused poor
  low frequency magnitude at phase response.
  The fix is to shift the timedomain response by 256 samples

LspCAD 6.60 (2020-03-15)
+ Max number of data points in time domain response increased to 65536

LspCAD 6.52 (2019-04-28)
+ Minor error in FFT function in emulator causued deviation
  from target transfer function near half sampling rate
+ Shortest FFT in emulator set to 8192pt

LspCAD 6.52 (2018-08-10)
+ Badly initialized references fixed, yet again!
+ Serious referencing flaw in previous build fixed

LspCAD 6.52 (2018-08-05)
+ Display options for group-delay graps (among others) was not properly saved
+ Badly initialitized reference for radiation components could cause
  program crash when store/recall buttons was used

LspCAD 6.52 (2018-02-24)
+ Memory leak issue resolved
+ Problem with progam crash when store/recall buttons used frequently
  when emulator is running
+ Emulator Wave file mode supports 32bit floating point 2ch wave files
+ Emulator Wave file mode displays playout point

LspCAD 6.51 (2017-12-27)
+ Corrected error in Extenteded OFF-AXIS modeling
  for X-axis

LspCAD 6.51 (2017-10-28)
+ Loudspeaker unit (T/S model) :
 + Addition of extra delay parameter in "Other" to
    indicate acoustic center of driver.
 + High frequency model was not applied correctly
+ Baffle component, possible to simulate room response only

LspCAD 6.50 (2017-02-18)
+ Added graph that displays in-box pressure
+ Corrected error in OFF-AXIS data import that prevented correct reading of
  negative angle measurements
+ Corrected wrong export of impulse responses from emulator

LspCAD 6.41 (2016-02-28)
+ Corrected model for TL speakers with decreasing cross-sectional area
+ Component area increased to 1920x1200
+ Descriptive text added to BiQuad filters

LspCAD 6.41 (2015-04-03)
+ Added log Y axis option for impedance graph

LspCAD 6.40 (2015-01-01)
+ Location of LspCAD 6 temp folder can now be specified by means of the environment
  variable LSPCAD6TEMP . This may solve a few strange copy, store and recall and
  optimizer undo issues that may occur in Windows 7 and 8.
+ Clone projects, copy/paste and undo in the optimizer did not work properly
  in the cases that the LspCAD 6 projects was on another disk than the LspCAD 6
+ Export function: Possible to export the off axis overlay graps as off axis
  extended format.
+ DCX2694 : Computation of transfer functions for shelving and parametric EQ did
  not match 100% with measurements
+ Extended off axis format : Sorting function added to make sure that data is
  interpolated correctly even though the angles are not specified in increasing
  order. Furthermore, for simplicity, combination of non-zero X and Y angles are
  discarded. This means that Y angle must be zero when non-zero X angles are
  measured and vice-versa.
+ Krash when impedance graph tab selected, fixed.
+ Klippel T/S data import of Sd parameter, fixed.

LspCAD 6.38 (2011-12-30)
+ Export funtion
+ Problems with exporting TS driver response fixed
+ Problems with exporting group delay fixed
+ Polar map update caused temporal error in SPL graph
+ Unnecessary warnings of missing files fixed
+ Suspension creep model improved according to paper
  Ritter et al "Modelling Viscoelasticity of Loudspeaker Suspensions using Retardation Spectra"
  AES 129, paper 8217
+ RMS current reading for inductors in summary
+ RMS voltage reading for capacitors in summary

LspCAD 6.37 (2010-08-07)
+ Small LspCAD logo added to graphs
+ Highest node number was not possible to measure (voltage)

LspCAD 6.37 (2010-06-20)
+ Optimizer: Phase optimizer did not compute actual phase
+ TS driver: Praxis import not working properly
+ DXC2496
+ Bypass and Invert checkbox did not have any effect  
+ Step up/down of parametric EQ Q-value
+ Main window. Component list made scrollable

LspCAD 6.37 (2010-05-15)
+ Polar map did not work with TS driver components
+ G(s)/G(z) component, 1st and 2nd order
  allpass added to BiQuad filter
+ TS import (Praxis, Klippel, Clio) did not always work
+ Diffraction analysis speed improved considerably especially
  when used with polar plots
+ Accuracy of loss model in horn component improved,
  works well with concatenated transmission line segments
+ Optimization of advanced boxes did not always work
+ Open component ialog boxes now update properly when optimizer runs
+ Emulator, ASIO input channel range increased

LspCAD 6.36 (2009-08-23)
+ Possible to optimize impedance with phase target
+ List of missing files presented when projects are opened
+ RichEdit controls replaced to solve issue with non-western character sets.

LspCAD 6.35 (2009-05-09)
+ Use of recall buttons could result in loss of imported data
+ Sqrt domain error related to off axis simulations fixed
+ Delay value in driver component not correctly applied if "As drv 1" checked

LspCAD 6.35 (2009-04-04)
+ Optimizer, modeling of Q-value wrong by a factor 2.0
+ Off axis power response, possible to select RMS sum instead of complex sum

LspCAD 6.34 (2009-03-08)
+ Behringer DCX2496 and XTA. Change of EQ did not update EQ slope in dialog.

LspCAD 6.34 (2009-02-14)
+ Valentines day version !
+ Min value for Vas changed to 0.001l

LspCAD 6.34 (2008-12-14)
+ Occasional atan2 error fixed
+ Optimize checkbox did not work properly for advanced box mode
+ Recall sets could cause loss of reference to SPL/impedance data
  if files was located in different folders
+ Baffle diffraction simulations did not always update properly
+ Problems with relative paths fixed
+ Optional to use off axis phase lag modeling

LspCAD 6.34 (2008-08-17)
+ Simulated SPL for speaker boxes, changed to true 4pi radiation
  -->  -6dB difference difference from previous versions.>

LspCAD 6.34 (2008-08-13)
+ Horn component, bugfix for conical horns
+ Locations of imported data stored as relative paths with project file location
  as referense, this makes it more simple to distribute project files.
+ Behringer DCX2496, number of EQ elements increased to 9

LspCAD 6.33 (2007-10-21
+ Ke (semiself inductance), max value set to 10sH
+ Parametric EQ using BuQuad filters
   (Behringer, DBX pro, XTA and G(s)/G(z) component).
  Erroneous implementation caused wrong implementation of Q factor setting.
  The resulting Q was wrong by a factor 2.0.
+ Bandpass box (advanved box), rear box properties did not cause an update of the
+ Recall button did not update screen correctly if working/display range updated.

LspCAD 6.33 (2007-06-30)
  New stuff
+ Driver component
+ Extended SPL data format
+ Larger loss factors allowed in ports.
+ Possible to optimize Ke in TS driver component
+ Digital BiQuad filter, Pole-shifter added
+ Complex impedance component, limitation to 200ohm removed.
+ Off axis simulation to +/-180 deg possible (also for polar plot)
  Bug fixes
+ File close was missing in TS driver component, casued
  problem when Store/Recall buttons used.
+ Extra check for window placement when program started.
+ Switch component, unstable simulation condition fixed.
+ Passive radiator box template
+ Optimize main switch did not work properly in advanced mode.

LspCAD 6.32 (2006-10-17)
+ justMLS
+ Possible to set buffer size.
+ Initial dry run time increased to 200ms

LspCAD 6.32 (2006-10-13)
+ justMLS
+ Measurements more stable
+ Behringer DCX2496, XTA and dbXPro component
+ Bessel filter at low frequencies had wrong response due to
   fix build 2006-10-09
+ Node analysis
+ Designs using horn component created close to unstable simulations
   due to fix in build 2006-10-09

LspCAD 6.32 (2006-10-09)
+ Save button in main window
+ dbXPro component
+ XO frequencies was not possible to modify
+ Berhringer DCX2496 and dbXPro component
+ Corner frequencies was not correct for odd order and
   bessel filters at high frequencies
+ XTA component
+ Corner frequencies was not correct for odd order and
   bessel filters at high frequencies
+ Crossover emulator
+ Support for ASIO cards with up to 18 output channels
+ Input channel pairs 1&2-15&16 adressable (ASIO)
+ Optimizer
+ Position of legend is kept during session
+ justMLS
+ Possible to select DirectSound or ASIO soundcard access.
   For ASIO access it is also possible to select input for ch1 and ch2
   (input ch 1-16)
+ screen size can be adjusted
+ soundcard setting saved in justmls.cfg    
+ Store path for justmls.cfg and justmls.cal stable

LspCAD 6.31 (2006-08-29)
+ Crossover emulator
+ Digital input working (ASIO mode)
  + Int24, Int32 and Float32 support.
  + Security measure to avoid lockups under high CPU load conditions introduced.
+ Crash bugs related to store/recall and also project save/switch solved
+ Complexity of circular convolution reduced somewhat. 
+ Excessive memory usage in digital filters fixed.
+ Emulator streaming temporarly stopped when Recall buttons pressed
+ Optimizer
+ Opt switch in groups not saved in project files 
+ Store/Recall buttons disabled when optimizer running
+ Store/Recall buttons
+ Recall executed twice by mistake when recall button pressed.
+ Log10 sing error related to the use of GS, DCX, DBXpro and XTA components fixed.

LspCAD 6.30 (2006-06-07)
+ Optimizer
  + Setup of optimization simplified as "optimize with respect to .." setting is removed
  + XO point lock is improved with a lower risk of divergent behavior.
  + Grouped components has a main optimize checkbox option, this makes it
     possible to turn off optimization for entire filter sections with just
     one operation
+ Crossover emulator
  + ASIO support, possible to select input pair for multi channel input ASIO cards.
  + Emulator was not closed correctly in certain conditions.
  + Emulator is always on top.
  + Noise bursts when R1..R8 buttons used removed
+ Store/recall sets saved at correct locations, for instance if one click on S3 and
   save the project the set will be available at R3 when the project is opened again.
+ Possible to set orientation of T/S drivers, side mounted drivers now possible to model.
+ Snapshot, a few bugs fixed.
+ Schema, can be printed with option fit meaning that the schema printout fills the entire paper.

LspCAD 6.20 (2005-11-23)
+ Klippel TS import, Sd, Vas and Mmd was not imported properly

LspCAD 6.20 (2005-11-18)
+ R1..R8 button,
  + Large memory leak problem, partly fixed.
     Still some memory leak problem though.
  + Crash problem when used with crossover emulator fixed.
  + Noise problem when used with crossover emulator fixed.
+ T/S parameters, some parameters accidentially optimized even though they was not selected for optimization.

LspCAD 6.20 (2005-11-03)
+ Port resonance frequencies not updated correctly in certain cases.
+ Store/Recall sets, severe bug (program crash) fixed.
+ Buttons/menu picks makes it posible to bring Main form, graph and schema to front, very handy for low resolution monitors.

LspCAD 6.20 (2005-10-11)
+ G(s) G(z) component, Digital phase lineal FIR filter component added, possible to simulate and
   export filter coefficients for FIR filters with filter orders 129..4097 with various window options.
   Open examples/phase linear digital XO.lsp for an example how this can be used in a
   digital phase linear loudspeaker system.
+ Crossover emulator, Variable Causal filter margin, this feature is needed to avoid that crossover
   emulator impulse response is chopped off in beginning

LspCAD 6.20 (2005-10-09)
+ Store / Recall (S1...S8, R1..R8) sets saved when LspCAD closed,
   reloaded when LspCAD started.
+ Crossover emulator. Impulse response exported automatically to LspCAD folder
   when Circular convolution used. Filename of exported coefficients is   
   LspCAD_6_xo_emulator_1.txt, LspCAD_6_xo_emulator_2.txt etc.
   Fileformat is ASCII text format with one coefficient per line.
   Impulse response can be used e.g by BruteFIR.
+ Near boundary reflections only case improved somewhat.
+ Horn component
  + Pens saved
  + Loss model improved, possible to use component when simulating transmission lines.
+ Non linear/thermal modeling, warning message displayed when main switch in
   settings dialog is not enabled

LspCAD 6.20 (2005-09-27)
+ Digital BiQuad filters (G(s)/G(z) component), Max sample rate increased to 200kHz,
   Possible to quantize filter coefficients
+ Bassreflex port, possible to set end correction multiplier to simulate eg port locations close to corners.
+ Polar map computation caused erroneous on axis response for individual drivers in SPL graph.

LspCAD 6.20 (2005-09-23)
+ Severe memory bug fixed, really odd that things worked with this bug, this bug can explain a lot of possible program crashes.
+ Size of KHF tool reduced slightly to fit in 1024x768 resolution
+ Warning text displayed if components are connected ie. if:
+ OP amp non-inverting input connected to GND
+ Hot connector of T/S driver connected to GND
+ Active components without buffering connected direct to passive components
   The above cases will give wrong simulation results

LspCAD 6.20 (2005-09-20)
+ KHF tool !, a universal tool for merging and adding SPL data.
+ New diffraction simulation , including 2nd order reflections and off-axis behavior.
+ Near boundary reflection simulation .
+ Advanced box simulation mode for closed/bassreflex/passive radiator and bandpass boxes.
  This is gives almost the same looks to the box modeling as in good old LspCAD 5!.
  This feature works for the boxes defined in the template section.
+ Voltage graph (pro version)
+ Current graph (pro version)
+ Transformer component takes N1:N2 ratio instead of 1:N ratio,
  component could sometimes give unstable results (fixed)
+ Schema scroll position unique for every project.
+ Store / Recall (S1...S8, R1..R8) presets completely redone.
  This time all components are stored/recalled, it is also possible to change topology between the sets.
+ Last opened project files displayed in the File menu
+ Recompute Mmd/Mms bug fixed.

LspCAD 6.10 (2005-03-31)
+ Optimizer, lockup problem fixed, problem related to imported targets only
+ Snapshot Open and Save As functionality
+ Nonlinear BL(x) and Cms(x) modeling (pro version only) , two options, SWEPT mode or based on PSD.
+ Nonlinear port modeling (pro version only).
+ Store / Recall, all components except Driver / TS driver components have store
   recall functionality.
   NOTE THAT The store recall sets are not saved with the project...
+ TS parameters, occasional odd values when parameters added
+ Negative angles possible in imported polar response
+ Port component, possible to increase loss

LspCAD 6.00 (2005-02-09)
+ Optimizer, some passive components was accidentally listed several times in the checklist box.
+ Complex impedance component, this component makes it possible to import e.g the measured impedance of an inductor. This can be useful in cases where e.g the skin effect of a real inductor makes the built in inductance model less accurate.
+ Dissipated power over resistors (pro version only). If termal modeling is enabled (see ch 8 in manual) the computed power dissipation in resistors is presented in the component list. Note that for best match with reality it is recommended to import one of the PSD files located in the lib folder as the power spectral density of the music clips has an impact on how the heat is distributed over the components.
+ Store/recall buttons. **This feature is still under construction**. One limitation is that the stores values are not yet saved. Another limitation is that this currently works ONLY FOR passive components. Both limitations above will be resolved in a later build.

LspCAD 6.00 (2005-02-02)
+ Inverting drivers did not have an effect in the crossover emulator + Optimizer, a checklist box is added where one can switch on or off the main optimization switch for passive components (click on the button with caption ">>>" in upper left corner in optimizer dialog to see list)

LspCAD 6.00 (2005-02-02)
+ Inverting drivers did not have an effect in the crossover emulator
+ Optimizer, a checklist box is added where one can switch on or off the main optimization switch for passive components (click on the button with caption ">>>" in upper left corner in optimizer dialog to see list)

LspCAD 6.00 (2005-01-27)
+ Malfunction if projects with G(s) BiQuad components opened (sorry Pat)

LspCAD 6.00 (2005-01-25)
+ Maximum vertical size of main window reduced somewhat (to fit better with 1024x768 resolution)
+ Open project file bug fixed. Bug caused occasional loss of components when project was opened.
+ Number added to beginning in project and TS driver list box to increase readability.
+ Prinout of schemas became a mess of current and previous schemas

LspCAD 6.00 (2005-01-13)
+ Possible to select what cone excursions that should be visible in cone excursion graph
+ Undo button disabled if clicked, there is only one undo level possible after all
+ Possible to get relative y-axis readings if right mouse button is clicked in graph
+ Yet another rare node numbering bug fixed.
+ Red warning circle if components are loaded with passive circuits when the simulation does not allow this,
  for instance G(s) components should not be loaded by passive components such as resistors, driver units et.c.
+ Working waveguide component, can be used for horn and possibly also TL modeling.
  Also possible to simulate U-frame and H-frame dipole loudspeakers with this component.
+ Possible to simulate dipole loudspeaker (baffle type), does not give a correct off axis response though.

LspCAD 6.00 (2004-12-15)
+ Rare bug when working range changed fixed
+ Main window widened somewhat
+ Termal modeling enable (main switch) in settings dialog
+ Save session option makes it possible to save all open projects in one file.
+ Box load factor can be adjusted in boxload settings

LspCAD 6.00 (2004-12-05)
+ Show component list button working can be used to hide compent list
+ Occasional erroneous underlines/italics in component list removed

LspCAD 6.00 (2004-11-30)
+ Use fc multiplier option in G(s) component did not work properly
+ Printout problem (blank pages) solved
+ Optimize variable Q target, highpass and lowpass Q values interchanged
+ Code prepared for standard version

LspCAD 6.00 (2004-11-22)
+ Uninitialized variable sometimes caused odd behavior, for instance impossible to open settings for passive radiator
+ Warning message if wizard group is ungrouped
+ In TS driver parameter list, offset error caused wrong paramter to be edited when a line was double clicked.
+ Possible to see voice coil inductance only on load impedance
+ Config dialogs are closed when one actively close them or when one open another config dialog

LspCAD 6.00 (2004-11-15)
+ Passive HP/LP filter wizard added (right click in schema in edit mode, select Insert...).

LspCAD 6.00 (2004-11-08)
+ Screen redraw in edit mode made faster

LspCAD 6.00 (2004-11-04)
+ Rare problem with cascaded wire components fixed
+ LSPCAD6WORKINGDIR was not working properly if '\' character at the end

LspCAD 6.00 (2004-11-02)
+ Program crash bug related to the use of baffle components fixed.
+ Dropdown list for range setting changed to readonly
+ Extra transfer function offset/enable not saved in project file
+ Scrolling problem and fixed first row in TS parameter list fixed
+ LSPCAD6WORKINGDIR environment variable makes it possible to have another directory than the LspCAD folder as default working directory
+ Baffle diffraction setting for radiation component not saved

LspCAD 6.00 (2004-10-26)
+ Special Win98 SE patch needed to make sure that Settings/Optimizer/Emulator dialog can always be opened.
+ Diffraction analysis error fixed.
+ TS driver Vas got wrong value when fs changed
+ Possible to open .unt files generated in older versions of LspCAD
+ LambdaS (creep factor for Cms) added to list of TS paramters.

LspCAD 6.00 (2004-10-17)
+ USB copy protection dongle operating
+ Wizard for G(s) LP/HP filtrers
+ Color distribution for polar map improved
+ Memory leak fixed. + Clipboard cleared when program closed
+ Default TS values set to (almost) zero.
+ Problem with imported files not in same path as project file fixed.
+ A few typos fixed.


Get LspCAD 6 + updated manuals below. 
Note that LspCAD 5 in standalone version is no longer supported or available as download.
LspCAD 5 is however bundled with LspCAD 6, please look for the upgrade offers on this website.

Right click and select "Save Target As.." in the dropdown menu




Manual LspCAD 6

Manual LspCAD 5.25 pro