Speaker Box Cad Programs

17-09-2021

Speaker Box Cad Programs

0. Introduction

Free Cad Programs
Cad Programs For Home Design
Speaker Box Cad Programs For Free

Jul 15, 2015 This AutoCAD tutorial is about basic 3D modeling with some easy command, Check it out!!! Term-PRO Loudspeaker Enclosure Design Software Video Tutorial. Transmission line speaker box design. The software offered here can take your speaker design to the next level Boxnotes Determine your enclosure dimensions taking into account the space occupied by ports and the driver. Adjust the height / width / depth ratios to minimise problem resonances within the box.

Subwoofers have received a lot ofattention from audio softwarewriters primarily because of our obsession with bass. Moreover,simulator writers find that, subwoofers are notnearly as difficult to model compared to loudspeakers with relativelyhigh frequency driver units. Becauseof this, countless subwoofer simulators can be found in theInternet, some are free and some are not. This is myattempt to provide a freeware subwoofer program that willhopefully prove itself useful to DIYers.

1. Background

The very first version of SubwooferSimulator was abasic Vented-Box calculator compiled in one little MS-DOS command-lineutility. The MS-DOS executable file used equations from RayAlden's book,'Advanced Speaker Design for the Hobbyist and Technician.' The utility simply calculated net enclosure volumes and port dimensionsoff one 'alignment'. It was all I could do since I neither hadthe time nor patienceto hard code a graphical user-interface using only a command-linecompiler. I had to use a 2nd software to plot my program'soutput files.

It was when Borlanddecided to let AustralianPersonal Computer Magazine release Borland C++Builder 3.0 Standard to the public that I started my journeyinto the challenging world of loudspeaker CAD softwaredevelopment. After a month of reading Builder's helpfiles andexampleprograms, I was able to build a fully-independent simulation program,which is pictured below.

Fig. 1: First SubwooferSimulator.

The mosttime-consuming part was making the graphingfunctions. I disliked what was already available, so I made myown plotting routines. As you can see, the plots weren't perfectaround the edges; curves tended to 'overshoot' the graph space. After the graphing functions werecompleted, though not necessarily bug-free, the next time-consumingpart of making the user-interface followed. Anyway, it wasAugust, 2001 when I released the old version to the public.

2. Specifications

2.0. System Rquirements

Any machine runningWindows 95 is good enough.

2.1. Electroacoustics Model Download captain tsubasa ps2 for pc tanpa emulator.

Subwoofer Simulatoruses pre-programmed 'equivalent circuits' tomodel 7 types of subwoofer designs. All the models have theirelectrical and mechanical parts transformed to their acousticalequivalent, which greatly simplifies circuit calculation. Pleasesee Electroacoustic Modeling Of AVented-Box Loudspeaker for an example of this simulation method.

The models used are ofthe small-signal type, and the simulation results are accurate so longas the driver unit in question remains linear at the (user-adjustable)simulation conditions. The results can be relied upon so long asthe driver unit stays within linear Xmax, thermal power handling limitand cone breakup.. All of which are conditions easily-met giventoday's high-quality subwoofers from Adire Audio, AE Speakers (formerlynamed Stryke Audio) etc.

Subwoofer Simulatorsimulates:


Sealed	Vented	Enclosurewith Passive Radiator	4th-orderBandpass


Parallel6th-Order Bandpass	Series6th-Order Bandpass	8th-OrderBandpass

Subwoofer Simulator allows for 1, 2 orall 7 types of subwoofers to be simultaneously simulated, however, onlyone instance of each type is supported in the current softwareversion. The next version will be more flexible and have lotsmorefeatures.

I have made thegraphing part of subsim to show multiple curves in one page only sothat users may clearly see the relationship between each curve. This isnot only educational for beginners, but also informative for knowledgeddesigners. Moreover, all curves corresponding to each box type areshown on the same page, which allows for easy comparison of box designs.

The currentversion of subsim does not automatically adjust the extremes of theY-axes. However, all X-axis and Y-axis maximum and minimum values maybe easily changed by clicking the supplied Up/Down buttons or Up/Downkeys for keyboard bashers.

SubwooferSimulator plots:

- System SPL and phase

- Cone and port speed
- Cone and port excursion
- Group Delay
- In-Room frequency response (given the user's room transfer function)

and lets the user save the graphsin FRD/ZMA (textual) format. The format allows for postprocessing with any text editor and other audio software such as theones from the FRDGroup. The format is also used by commercial software such asSoundEasy, LEAP, LspCAD etc. FRD files are simply text filescontaining, for example, the following data.

Frequency (Hz)	Magnitude (dB)	Phase (degrees)
10.000	80.000	90.000
11.000	82.000	85.000
12.000	83.000	80.000
..	..	..
.	.	.
.	.	.

Writing Bitmap screenshots ishandled by Subwoofer Simulator simply by clicking on the graph space orby going the long way of clicking on the File / Write Screenshotdrop-down menu.
In order to help the user distinguish which curve is which, the userhas the option to change the color of each curve. Colors areautomatically saved when a simulation is ended or when subsim isclosed; the last saved colors are loaded everytime subsim is opened.
Clicking anywhere outside the graph space recalculates everything.

2.3. Create/Load/Save Project Files, DriverFiles, Box Files..

Projects can be saved and loadedfor convenience. This greatly saves time in re-entering designparameters or making derivatives of a known good design. Exceptfor which sub-windows were open, everything is saved in one file, theprogram even remembers graph colors and axis extremes. Graphcolors are automatically-saved just before ending a session with theprogram or complete program closure. Graph colors can be resetjust in case the corresponding settings file becomes corrupted. Enclosure and driver details can be separately saved and loaded as well.

Using measurements of the user'slistening room, subsim can show the effects of which with a candidatesubwoofer design. Subsim simply adds the transfer functions of bothsubwoofer and room then displays the results.

When any of the checkboxes in theGraph Options | Available Curves tab is checked, moving the mousepointer anywhere on the graph space enables curve tracing. At thebottom-left-hand corner of subsim's window, the correspondingmagnitude, phase and frequency of the mouse pointer's position isdisplayed. Depending on which Y-axes are selected to be shown and whichY-axis is selected, users will see, for example, '88.123dB/-90.456degat 30.789Hz.' Any of the visible Y-axis may be selected for curvetracing simply by clicking on the desired Y-axis type.

Not all woofers come with enoughThiele/Small parameters. To compensate, Subwoofer Simulator cancalculate the requried parameters.. given a set of extraparameters.

Box volume, Vb, port radius, Av,port length, Lv, and box resonant frequency, Fb are interrelated to oneanother. I have made subsim to behave as follows.

Enclosure Part	-	Changed by adjustments of any/all of:	-	Notes
Fb		Vb, Av, Lv, PR parameters, number of vents/PRs
Lv		Vb, Fb, Av, number of vents
+m		Fb, number of PRs
PR Parameters		number of passive radiators		to reflect a single equivalent PR

Physical port length isinfluenced by end-correction, (and user defined values for) speed ofsound and air density. Subsim calculates the effective port length byadding 0.850*Av (for flanged end) and 0.613*Av (for unflanged end) tothe physical value, Lv. Please seeCylindrical Ports and Flared Vents for more details.

3. Quick Startup Guide

3.0. Double-clicksubsim.exe and then click on File / New Project

3.1. Enter driverThiele-Small parameters or load a pre-saved driver file.

3.2. Enter simulationparameters and then select which enclosure type to simulate.

3.3. Click on Boxes /Vented to bring up the Vented-Box Details window. Enter yourenclosure's parameters and then select which curves to plot.

Free Cad Programs

.. Quitestraight-forward. There really is no particular order, which maymake Subwoofer Simulator's user interface a little 'different' to someusers.

4. Notes

- Enclosure optimization isdisabled and completely removed from the program. The code works,but is 'randomly' unstable, so I need to work on it some more.

-- Upper frequency roll-off isdue to voice-coil inductance, butremember that the SPL curves are only accurate up until Cone Breakupsets in. For subwoofers, Cone Breakup happens well away from thepassband of interest.

-- Radiation is intohalf-space. Subtract 6dB from the plotted SPL to obtainfull-space radiation, however, remember that Baffle Diffraction is notsimulated. The easiest way to subtract 6dB from the SPL is byhalving the voltage input.

-- I have built SubwooferSimulator to use the most commonly used measurementunits in this subject. However, to help you convert from onemeasurement unit to another, you may download Factor Conversion Tool.

-- multiple woofers may be usedwith the program simply bymanipulating the T/S parameters of the woofer used. The single-wooferequivalent T/S parameters are:

Cad Programs For Home Design

For x woofers in parallel:
Revc	=	Revc/x
Levc	=	Levc/x
Fs	=	unchanged
Vas	=	x*Vas
Qms	=	unchanged
Sd	=	x*Sd
Bl	=	unchanged
For x woofers in series, as above, but:
Revc	=	x*Revc
Levc	=	x*Levc
Bl	=	x*Bl

-- Please see Thiele-Small Parameters and Dual Voice-CoilDrivers for DVC simulations.

-- for an isobaric configuration,the effective parameters are:

For parallel voice-coils:
Revc	=	Revc/2
Levc	=	Levc/2
Fs	=	unchanged
Vas	=	Vas/2
Qms	=	unchanged
Sd	=	unchanged
Bl	=	unchanged
For series voice-coils, as above, but:
Revc	=	2*Revc
Levc	=	2*Levc
Bl	=	2*Bl

-- Project/Woofer/Box/Color filesare saved in binary format. Iwas going to use text mode saving/loading but this created anincompatibility with Windows machines which use the comma (,) as thedecimal separator (as I program using the full stop (.) as the decimalseparator). Text mode would have given the user the option to manuallyedit the project files using any text editor, but the incompatibilityproblem was unavoidable in text mode.

-- Subwoofer Simulator displayspeak or one-way excursion curves.

-- Input FRD files must not haveany comments whatsoever -- theinput files must only contain data or the program will refuse to acceptyour room measurements.