1. IJData, Luleå, Sweden http://www.ijdata.com
LspCAD 6
IJData, Luleå, Sweden

2. LspCAD = Loudspeaker Computer Aided Design
A software tool for the construction of loudspeakers.
Box modeling with predefined models for the most popular box types.
Crossover modeling for both passive and active analog and digital filters.
Box models and crossovers can be built in the same design.
Design with the objective to both enable fast prototyping and advanced design optimization.
Standard and Professional version.
Drag and drop interface.

3. Main window
Unlimited number of projects open (limited by system memory)
Template project
Contains templates for popular building blocks such as closed/bass reflex box, active 2nd order HP/LP filter.
Wizard properties for most of the templates, speeds up design considerably.

4. Schema window Up to 10 schema pages Two operation modes
Edit mode, add, move, delete components, pick components from component tray
Simulate mode, change properties (component values) and see result immediately

5. Schema window, edit mode
Passive components
Voltage source wire and GND (not exactly passive but located here anyway)
Resistor, Capacitor and Inductor, the latter two with ESR, loss and Ri.
Complex impedance component, makes it possible to import measured Z of eg. an inductor.
Ideal transformer with N1:N2 turns ratio.
Loudspeaker symbol for imported SPL and Z.
Connector symbol, makes it possible to connect between schema pages.
Switch, makes it possible to route signals in different directions or switch on/off filter legs.

6. Schema window, edit mode
Active analog/digital components
Ideal OP amplifier
G(s) G(z) fast prototyping filter blocks,
Analog HP/LP filter up to 8th order
Peak/Notch, allpass, bass/treble boost and 2nd order HP/LP eq.
Matlab directform filter coefficients.
Digital Pole/zero and BiQuad.
Imported transfer functions.
Phase linear FIR filters (up to 4097 filter taps)
Sum/add delay and buffer elements for rudimentary digital filters.
Models of commercial digital crossovers.

7. Schema window, edit mode
Box cabinet components
T/S parameter model
Box load and radiation component
Port and passive radiator component
Horn component
Baffle / Near boundary reflection component, makes it possible to simulate baffle diffraction and the impact of the reflections from the closest walls and floor.
Other components
User note component, add user notes on the schema

8. Schema window, simulate mode
In simulate mode component properties are accessed with either a left or a right click on the mouse.
Effect of property changes is seen immediately in the graphs.
A number of Store/Recall buttons makes it possible to compare designs fast.

9. Graphs A number of graphs shows most of the aspects of the design
SPL mag and phase and Transfer function
Impedance
Voltage/Current
Group delay and time domain response
Off axis simulation
Polar plot
Graphs can be cloned, this makes it possible to see many graphs at the same time.

10. Graphs, polar map
The polar map displays the off axis reponse as a function of frequency
Both vertical and horizontal polar map

11. Optimizer Optimize SPL, transfer function or impedance
Large number of options, slopes, notches/peaks etc.
Optimize with penalty function on low load impedance
Lock crossover frequencies in a given range.
Bandpass boxes can be optimized with a lock on total volume.
Undo button makes it possible to revert in case optimization turns out bad.

12. Snapshot
Compare different designs or the same design under different operating conditions

13. Tolerance analysis
Investigate how component variations affect the final result
Nominal, min and max data can be exported for pass/fail testing

14. Crossover emulator Emulate the crossovers without building them.
Use line input or WAV file as source
Compensates for protection capacitor (recommended for treble units) and cable losses.
Emulator impulse response automatically dumped to file for later use in externa convolver such as BruteFIR.

15. justMLS Measurement program Measure SPL or transfer functions
Measure impedance
Possible to merge near and far field measurements

16. KHF tool Combine near and far field measurements.
Add contribution from port and drivers for a total response.
Apply baffle diffraction to nearfield measurement.
Side mounted placement of drivers possible.

17. Templates
Templates are building blocks that are useful in everyday work.
Active templates
Passive templates
Loudspeaker boxes

18. More features Driver component
Off axis simulation, either piston model or imported off axis data
Thermal modeling
Can link to a baffle / near boundary component for simulation diffraction and reflection effects.

19. More features Box modeling
Based on electrical analog circuit models of the items constituting e.g a bassreflex box (port, box..)
Possible to build arbitrary boxes using building blocks
To make things simpler, templates for well known box types hide the circuit model (optional).

20. More features T/S Driver component Thermal modeling
Can link to a baffle / near boundary component for simulation diffraction and reflection effects.
Bl(x) and Cms(x) nonlinearity modeling, models impact of SPL and Z
Can import data from Praxis, CLIO and Klippel
Built in component editor

21. Demo
Get a fully working demo from

22. Thats all, thanks for watching!