The Woofer Box and Circuit Designer is an advanced woofer and box design tool using MS Excel. It has a complex box model that can simulate either sealed, vented, or passive radiator box results. However, it also has a filter section that allows you the ability to model a very wide range of filter response shapes. The intent of this program is to give you the tools you need to design a subwoofer using a wide variety of available plate amps, many of which posses varying degrees of equalization or crossover adjustment. The program will model other crossovers, digital processors, and equalizers as well. You may also import a filter transfer function or room response curve that was saved as an frd file from any other software, and this program will incorporate that imported data into the model and its results. The program can be useful for modeling more than just woofers. With it you can model a midrange or tweeter's excursion with a passive or active filter at varying power levels to get an accurate model of the demands on the driver.

The features of the filter section include a five band parametric equalizer, two stage second order high pass filter with adjustable Q (to model boost, and possibly a lower infrasonic filter), a selectable high pass and a selectable low pass filter that offers  a number of standard response shapes up to Eighth Order L-R, and a Linkwitz Transform section.

Graphs are provided that show frequency response, phase, impedance, maximum output, 2.83V sensitivity, filter transfer function, cone excursion, passive radiator excursion, vent velocity, group delay (filter, driver, and system), and Impulse Response. All calculations and graphs include the effects from the filter settings selected.

Finally, buttons are available to output final frequency response and phase to an frd file and impedance to a zma file (text files readable by other software). You can save the circuit response as an frd file as well to use in other software if desired. You may also save woofer and box parameters to a session file to build a library of designs, and you can save filter settings to a separate file. This allows you save a particular plate amp's response and use it many different woofers as you design.

You have the ability to change the frequency range to whatever range is desired. This range will then be used for all calculations, graphs, and save files (frd and zma). You may also save any graph at whatever size and shape desired as a small gif file. A Quick Tuning Utility Bar that allows you to step through incremental changes in Vab, Fb, and other parameters as you view the main graph for quicker tuning of the alignment.

Version 4.1 Update Info: Developed a work-around for a compatibility issue with the VBA module and Excel 2007. Further refined Ql, Qa, and Qp in the box model. Added the ability to design by box dimensions and copy to the box model.
Version 4.2 Update Info:
Added Qp (port losses) as a variable to all calculations. Clarified the Q values in the pop-up comment boxes.
Version 4.3 & 4.31 Update Info:
Corrected impedance calculation to include series resistance.
Version 4.5 Update Info:
   Added ability to import both active filter responses and external room / baffle responses into the simulation.
   Corrected problem with the imported response interpolator in the previous version when the ranges were changed.
Version 5.0 Update Info:
   Added save and retrieve database features for woofer / box / tuning combinations
   Added retreivable database for passive radiators
   Improved sealed box analysis to include the effects of stuffing (Qa) and leakage (Ql)
on the Qtc of the system and the overall response
   Corrected error in the save to memory line on the main graph
   Improved the functions and display of the main graph
   Improved the use of imported baffle and room curves
   Improved the use of imported filter transfer functions (You must have "Filters Enabled" to see this curve included in the response. Turn off all other filter functions to show only the imported filter curve).
Version 6.0 Update Info:
   Improved compatibility for recent versions of MS-Excel

 Spreadsheet (and all previous versions), its VBA Modules, and its file structure -
© Copyright 2001- 2019
Jeff Bagby - File Design, Structure, Mathematics, and selected VBA routines
Charles Laub - Selected Mathematics
Paul Verdone - Selected VBA routines
File is Free for personal DIY Speaker Design use.
Commercial use is prohibited without prior authorization of the author
Info: click here to EMail Jeff Bagby

WB&CD Excel file download link:

Woofer Box and Circuit Designer 6.0    (1719 kB)

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The Woofer Box and Circuit Designer 6.0
last update: July 28, 2019