This demonstration software runs on Macintosh 512K, Macintosh Plus and Macintosh SE computers running system software earlier than Version 7.. It allows you to design and examine the low frequency characteristics of bass reflex, closed box (acoustic suspension) and infinite baffle types of enclosures. Thiele-Small driver parameters are used to calculate the response for various design trade-offs. These parameters are generally available for better quality speakers and may be measured by various techniques for drivers which have no published data. For demonstration purposes, the Thiele-Small parameters are fixed, requiring the user to buy MacSpeakerBox in order to use specific parameters.
The program first computes design parameters for optimal bass reflex and closed box enclosures as a starting point for your design. You may then enter enclosure parameters such as different volumes and port dimensions for two different designs and then compare all four in different combinations relative to low frequency response. The MacSpeakerBox program is particularly valuable when comparing various drivers vs. volume required before you purchase the driver.
Generally you will find that drivers with small magnets relative to their size will have a high Qts, which will result in large enclosures. Those with a Qts of approximately 0.4 will have a volume about equal to Vas and those with a low Qts will have cabinets smaller than Vas. The design tradeoff becomes one of driver characteristics, enclosure size and low frequency response. You can examine the response of an infinite baffle by just entering a very large volume such as 1000 cu. ft.
Getting Started
The screen contains "buttons" on the lower half of the screen which require just a single mouse button click to activate. These buttons are almost self explanatory. The first button to click is "Enter Spkr. Data" which will enter a fixed set of Thiele-Small parameters for demonstration purposes. Having entered the data you will note that a table appears showing parameters for optimal bass reflex and closed box enclosures. You may now enter your own designs by answering the questions after clicking the "Enter Design #1" or "Enter Design #2" buttons. After entering 1 or 2 designs, you may plot the low frequency response of the designs in various combinations by clicking on "Plot ALL", "Plot #1 & #2", "Plot #1 only" or "Plot #2 only". Other buttons function as follows:
"Review Designs" - Displays the design parameters table
"List LF Resp." - Lists numeric values for the low frequency response of all four designs (your two and optimal bass reflex and closed box designs) to the screen in tabular format.
"Print Response." - Lists the low frequency response of all four designs as well as design parameters to the printer in tabular format.
"Make Data File." - Creates a data file that may be used by spread sheet programs for storage or additional plotting. This feature may be used to compare and plot many different driver and enclosure designs in any combination.
"Print Screen - Prints the screen as currently displayed including the time of the run as shown in the lower right hand corner. If you are using a laser printer, screen print may or may not work depending on the laser printer driver software in your system folder. If it does not work, you can save the screen as a file by pressing the FUNCTION-SHIFT-3 keys and then print it from a drawing application program.
"QUIT program" - Quits the program
If text on the screen does not appear "clear", it is because you do not have the Geneva fonts in your system. Use the Font D/A Mover to install Geneva fonts.
To obtain your copy of MacSpeakerBox, send a check or money order (no cash) for $39.95 to:
