IJData, Luleå, Sweden. LspCAD 6

1. LspCAD 6

IJData, Luleå, Sweden
http://www.ijdata.com

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
http://www.ijdata.com

22.

Thats all, thanks for watching!