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Copyright / Disclaimer (c) 1991, 1994 By Hyperformance SoftSystems & Matt C. Gartner. All rights reserved. Reproduction or use of editorial in any manner is prohibited without expressed written permission by the author. No patent liability is assumed with respect to the use of the information contained herein. While every precaution has been taken in the preparation of this manual, the publisher and author assumes no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information contained herein or the use of the SpeakerDES system. Trademarks SpeakerDES is a trademark of Matt C. Gartner and Hyperformance SoftSystems. IBM PC/AT, EGA, VGA are trademarks of IBM Corporation. Epson FX is a trademark of Epson Corporation. LaserJet is a trademark of Hewlett Packard Corporation. ----------------------------------------------------------------------------- CONTENTS ----------------------------------------------------------------------------- SpeakerDES System Requirements Installing SpeakerDES Setting Up SpeakerDES Running SpeakerDES Controls and Conventions Window Usage Loudspeaker Design Basics The Driver The Enclosure Ported Closed Understanding Frequency Response Graphs What Kind Of Enclosure Is Right For You? Crossover Design Basics Introduction To Components What is "Order"? Crossover Points SpeakerDES Design Approaches Approach # 1 Approach # 2 The SpeakerDES Screen 1. Main Menu Bar 2. Side View Area Description & Functions Side View Contact Points To Manipulate Side View Shape Space Specifications & The Side View 3. Front View Area Description & Functions Front View Contact Points To Manipulate Front View Width Space Specifications And The Front View The ADD And REMOVE Action buttons 4. Specifications Area Description Of Specifications Editing Data In the Specifications Area 5. Response Requirements Area Manipulating The Response Requirements Realistic Response Requirements Variance Factor Warning Windows SpeakerDES Functions FILE Load FILE New FILE Save FILE Print FILE Save Response EQ FILE Save Overvolume Mode FILE Exit LOOKUP Driver Spec/User Driver Initial Procedures Selection Method Simple Driver Selection Driver Search Driver Codes LOOKUP Space Spec/User Space ANALYZE Single Graph / Comparison ANALYZE Optimum Volume ANALYZE Advisor UTILITIES Modify User Driver Adding A Driver Deleting A Driver Editing A Driver UTILITIES Modify User Space Adding A Space Specification Deleting A Space Specification Editing A Space Specification UTILITIES Crossover Design UTILITIES Compare Drivers UTILITIES Convert Metric UTILITIES Overvolume Mode UTILITIES Screen Saver UTILITIES Clock SELECT Enclosure Type SELECT Frequency Points SWITCH HELP GLOSSARY ------------------------------------------------------------------------- SpeakerDES System Requirements ------------------------------ The SpeakerDES system requires: 1. IBM PC/AT/286/386/486 computer with at least 512K RAM. 2. EGA or better (VGA, SVGA) graphics. 3. Microsoft-Compatible Mouse. (Logitech, Genius Mouse, Etc.) 4. Optionally, a printer (Epson FX-compatible or HP LaserJet- compatible). 5. At least 470K free hard disk space (or 470K floppy disk space for Floppy installations. ie 720K, 1.44Mb, 1.2Mb floppy drive). If your computer fails to meet all requirements (Except #4), SpeakerDES will not run properly or at all. ------------------------------------------------------------------------- Installing SpeakerDES --------------------- To install SpeakerDES on your hard drive, follow these procedures: 1. Switch to the directory where you unpacked the SpeakerDES archive. 2. At the prompt enter, INSTALL and press the ENTER key. 4. Press Y to confirm the installation, N to abort it. 5. Enter the name of the directory you wish to install SpeakerDES in. 6. If you have entered the correct directory, enter Y to continue. If you have made an error in the directory name, enter N to re-enter the directory. 7. The floppy drive and hard drive will run for a few moments and the install will be completed. NOTE! SpeakerDES may be run from the floppy it came on (Provided it is a 720K or 1.44Mb 3 1/2" or 1.2Mb 5 1/4"). However, in this case there is no need to run the install program. See Appendix B - Floppy Disk Installations for more information on running SpeakerDES from a floppy disk. The final step before running SpeakerDES is to configure the system. This is discussed in the next section. ------------------------------------------------------------------------- Setting Up SpeakerDES --------------------- In order to perform properly, SpeakerDES must be configured for your particular system. The following procedure will explain how to configure your system. 1. First of all, change to the drive and directory SpeakerDES has been installed in. For a hard disk installation, the prompt might read: C:\SPKRDES> For a floppy disk installation, the prompt might read: A:\> or B:\> 2. Now type SETUP and press the ENTER key. 3. Next, the setup program will ask you for the SpeakerDES directory. Because you ran SETUP while you were in the SpeakerDES directory, all you must do is press the ENTER key at this question. 4. Following the above question, the setup program will ask you to enter the directory you wish to store your enclosure design files in. If you wish to store them in the SpeakerDES directory, press ENTER. However, if you wish to place the design files in a directory other than SpeakerDES's, you will have to create a new directory manually (eg. MD C:\MYDESIGN) 5. Next, you will be asked which type of printer you have connected to your parallel (LPT1:) port. SpeakerDES supports two groups of printers. If you own a dot matrix printer, it is more than likely Epson FX-compatible. Most late model dot matrix printers emulate this printer. If you own a laser printer, it is more than likely it is Hewlett Packard LaserJet- compatible. A large number of laser printers emulate this printer. Enter your printer type. If you do not have a printer attached, you may select the "No Printer Attached" option. 6. You will then be shown the information you have entered and asked to confirm it's correctness. Press Y if it is. Press N if you made a mistake. You can then re-enter the information. 7. The setup is complete! *** Remember! Should your system configuration change, you can re-run SETUP and re-configure SpeakerDES. ------------------------------------------------------------------------- Running SpeakerDES ------------------ Procedure To Run SpeakerDES 1. Make sure your mouse driver is loaded. 2. Change to the disk drive which contains the SpeakerDES system and data files. 3. Change to the directory the SpeakerDES system is in (Hard disk installs only). 4. Type SD and press the ENTER key to run SpeakerDES. ------------------------------------------------------------------------- Controls and Conventions ------------------------ SpeakerDES uses a mouse as it's main input device and the keyboard as a secondary input device. The mouse is used to select items from menus and to point at objects on the screen. The keyboard is used for entering values and text in SpeakerDES. The mouse buttons perform the following tasks: Left Button - Selects options from menus - Presses action buttons on function windows. - Acts as an ENTER key when entering numbers or text data. Right Button - Pulls up Help menu when the user is not within any functions. If you have a three button mouse, ignore the middle button because it performs no function within SpeakerDES. ------------------------------------------------------------------------- Window Usage ------------ SpeakerDES uses what are commonly known as "windows" to perform many of it's functions. When a certain function has been selected from a menu, a window will open up on top of SpeakerDES's main display screen. Within this window will be a variety of "user changeable values" and "action buttons." With the exception of the Specifications area, user changeable values are displayed with a box around them. In order to edit a value, you must select the value by pointing at it with the mouse cursor and pressing the left mouse button. Type a new value, (Upper case letters are recommended so no searching or sorting conflicts occur.) and press ENTER or the left mouse button and you are done! If you wish, you may exit the editing procedure by pressing the ESC key. Action buttons are used to start an action. For example, if you are saving a design to disk, you may edit the design name using the above mentioned user changeable values procedure and then click on the action button "GO" to save the design. Once a windowed function has completed it's task or a clicked on the "EXIT" action button, the window will be closed. *** Note: Throughout this manual, the term "Clicking on <action button>" or "Clicking" means to point the mouse cursor (pointer) at the action button or object and pressing the left mouse button. ------------------------------------------------------------------------- Loudspeaker Design Basics ------------------------- In order to design effective loudspeaker enclosures it is important to understand some basic design principles. A loudspeaker design encompasses two main items: The DRIVER and The ENCLOSURE. The Driver ---------- The driver's main purpose is to produce the sound which we hear. It does this by changing the air pressure in the listening area at a variety of frequencies. The change in air pressure is what our ears sense. That is why it is very important that the drivers you select for your designs be of reasonably good quality. Driver manufacturers produce a set of specifications called Thiele-Small parameters (After Neville Thiele and Richard Small, two exceptional loudspeaker researchers) which are measurements of a driver's physical performance. These measurements are very useful when designing loudspeakers. The first measurement is called Qts. This value (Usually between 0.1 and 2.0) represents the total resonant property and mechanical damping of the driver. In simple terms, drivers with a high Qts (0.5 or greater) tend to produce greater vibration at their resonant frequency (Fs) than do low Qts driver (0.5 or less) Drivers with a high Qts also tend to have less built-in mechanical damping ability (The driver cone movement is not dampened by the magnet assembly to the same extent as low Qts drivers) The second measurement is called Fs. This measurement is the free-air resonance of the driver and it's value is measured in Hertz (Hz). To find this value, a driver is placed in the open air and attached to a frequency generator. The frequency where the speaker vibrates the greatest is the free-air resonance. For most bass drivers, the value of Fs falls somewhere between 20 Hz and 100 Hz. The lower the Fs, the better a driver can reproduce lower frequencies. The third measurement is called Vas. This value is a volume measurement (Cu. Ft. or Litres) which represents the volume of air which is required to produce an equal resistance to the driver's cone movement. Resistance to cone movement helps ensure the driver cone does not become over-extended and also keeps bass tight and un-distorted. *** SpeakerDES Tip *** Woofers with a Qts less than 0.48 work the best in ported enclosures. ------------------------------------------------------------------------- The Enclosure ------------- The enclosure's main purpose is to trap the negative sound waves a driver produces and provide a resistance to driver cone movement. Two very common types of enclosures are PORTED and CLOSED. Ported ------ A ported enclosure, in simplified terms, uses a pipe or port (an opening in the enclosure other than that used for the driver) to produce the effect of another driver working in a different frequency range. As the driver in the enclosure reaches the frequency range of the port, the air in the port begins to vibrate, producing a second resonance or vibration. This resonance helps to re-enforce bass and expand the range of bass frequencies re-produced by the driver. There are two important factors which affect the response of a ported loudspeaker: Volume and Tuning. (Derived from these two factors and the driver's information, are the enclosure frequency (Fb) and enclosure cutoff (F3) These tell us what frequency the port has tuned the enclosure to (Fb) and where the response curve is down 3 dB (F3)) Enclosure volume determines to a large extent how the loudspeaker will sound. If the enclosure is too large for the driver(s) in it, the bass produced may be lower in frequency but the sound level will suffer. On the other hand if the enclosure is too small for the driver(s) in it, the bass produced may be in a higher than desirable frequency range and have a "Boomy" sound. (Not to be confused with "Boom Cars." Their "boom" is from high sound levels and low bass) The second factor affecting response is tuning. If you are using high Qts drivers (Qts > 0.42), you will want to tune the enclosure (Fb) to a frequency lower than the driver's free-air resonance (Fs) in order to avoid a bump in the frequency response curve. On the other hand, if you are using low Qts drivers (Qts < 0.42), you will want to tune the enclosure (Fb) to a frequency above the driver's free-air resonance (Fs) in order to avoid a loss in bass response at higher frequencies. The best route to getting the correct response from your ported loudspeaker is to find the best volume for your driver(s) and then tune your enclosure according to the guidelines above. Please Note: Ported enclosures, due to their design, are less tolerant of mistakes than closed enclosures. Keep this in mind. Closed ------ Closed systems are the simplest type of enclosure to design because they consist of a sealed box with a driver(s) mounted in it. The fact that they are sealed means that the bulk of the loudspeaker's response relies upon enclosure volume. Once we have driver specifications and the volume of the enclosure it is possible to derive a value called Qtc. This value represents the sum of the previously mentioned factors and should not be less than 0.4 and not greater than 1.8. A Qtc of 0.4 effectively means you have moved your bass response to a lower band of frequencies at the cost of sound level, while a Qtc of 1.8 effectively means you have moved your bass response to a higher band of frequencies, at the cost of low bass response. Try to find a median value of 0.6 to 1.5. Closed enclosures, unlike ported enclosures, are relatively more tolerant of mistakes. *** SpeakerDES Tip *** Drivers with a Qts greater than 0.35 work well in closed enclosures ------------------------------------------------------------------------- Understanding Frequency Response Graphs -------------------------------------- Another bit of information that is very useful in design loudspeakers is called the frequency response graph. The frequency response graph's main use is to give the loudspeaker designer a view of how the speaker will respond to a band of frequencies. SpeakerDES designs from the woofer/bass driver perspective, and therefore uses a low band of frequencies such as those reproduced by a woofer or bass driver. To understand how it works, picture an EQ (Equalizer) on a home stereo. By sliding one of the bands on the EQ up, you increase the sound level of the frequencies controlled by that band (ie. Greater dB value). It is also the same with the frequency response graph. In the context of the frequency response graph, dB means the sound level of a particular frequency. Another fact to note about the Frequency response graph is a "Bump" in the response curve. It represents a band of frequencies which play louder than the 0 dB level off point. "Dips" produce the exact opposite effect of bumps, playing the frequencies spanned by the dip at a lower sound level than the 0 dB level off point. Bumps often indicate boominess and dips often indicate dead spots. ------------------------------------------------------------------------- What Kind Of Enclosure Is Right For You? ---------------------------------------- Deciding what kind of enclosure to use can be a relatively easy decision if you take into account a few things. Below is a comparison of ported enclosures and closed enclosures. Closed Ported Ease of design Easier Harder Error tolerance in design More Less Sound pressure level capability Less More The above comparison shows what is generally expected of these enclosure types. However, with some crafty design work and good drivers, one kind of enclosure can better another in a number of ways. If you are working with an automobile stereo system and wish to re-enforce bass output with woofers or subwoofers, you can opt for either enclosure type depending upon what your mounting space constraints are. If you have only a small area to work with, say in your car's trunk, you may want to opt for a closed enclosure system to conserve space. On the other hand you may want to fill your trunk with a ported enclosure and get the extra bass output from it. If you are working with a home or commercial stereo system, let the information above be your guide as well. It is probably safe to opt for a closed system when designing bookshelf speakers and a ported system when designing home or commercial speakers. ------------------------------------------------------------------------- Crossover Design Basics ----------------------- The drivers used in loudspeakers (Woofer, mid-bass, mid-range and tweeter) operate within a specific band of frequencies. Forcing any of those drivers to reproduce frequencies outside it's tolerated band is likely to cause blown speakers, distorted sound and generally bad results. Therefore, it is important that the frequencies each speaker receives be tolerable. That's the job of the crossover network. Introduction To Components -------------------------- SpeakerDES designs passive, parallel crossover networks, which use two electronic components, inductors and capacitors. Inductors are used to filter out frequencies higher than their calculated frequency. The calculated frequency depends on the desired crossover frequency and driver impedance. Inductors are measured in millihenries. Capacitors are used to filter out frequencies lower than their calculated frequency. This component's calculated frequency depends on the desired crossover frequency and driver impedance. Capacitors are measured in microfarads. The diagram below shows how we can apply these electronic components to a three-way speaker system: Symbol for capacitor | V | | /~~\ /----------| |-----| () | Capacitor | | | \__/ blocks bass and | mid-range freq. | | | Amplified | /--| |---- /~~~~~\ Capacitor blocks Sound signal in >>-----------|------| | | | /~\ | bass freq. | | | \_/ | | \__/\/\/\__ \_____/ Inductor blocks | tweeter freq. | | | /~~~~~~\ Inductor blocks \________/\/\/\___ | /~~\ | tweeter and | | | | mid-range freq. | \__/ | \______/ ------------------------------------------------------------------------- What is "Order"? ---------------- Another important principle in crossover design is the term "Order." Order is a way of describing cutoff rates in crossover networks. You may see such terms as "1st Order" or "2nd Order". Each higher order causes the cutoff rate to increase (by 6 dB per octave) and the slope of the "cutoff" (see below) lines to increase in steepness (ie. 1st order = 6 db/octave, 2nd order = 12 dB/octave) 0 -| 11111 | 111111 222 | 111111 2222 33 -6 -| 111111 22222 333 | 111111 22222 333 | 111111 22222 333 dB -12 -| 11111 222 33344 | 11 222 333 44 | 111 222 333 44 -18 -| 11 22 33 44 | 222 333 44 | 222 33 44 -24 -|___|_____2____|_____3____44_________|__________|_________ 1.0 Khz 2.0 Khz 3.0 Khz 4.0 Khz 5.0 Khz 1 = 1 st Order 2 = 2 nd Order 3 = 3 rd Order 4 = 4 th Order There are so many different "Orders" due to the variety of applications available for crossover networks. For instance, if you are designing a two way speaker system (Woofer and tweeter), you will probably get the best results with a first order system if you are using drivers which are tolerant of a wider band of frequencies. However, if your drivers are not as tolerant, you may find a higher order network (smaller band of frequencies) more appropriate. What is important to keep in mind is the frequency response each driver in your speaker system provides. You can then judge which crossover network will best fit your needs. ------------------------------------------------------------------------- Crossover Points ---------------- After taking into account the drivers, their frequency ranges and the type and order of crossover network you are going to use, it is now possible to decide crossover points. For a single driver system or a two-way system, you need only pick one crossover point. In a two-way system, this point determines where the woofer will stop producing higher frequencies and where the tweeter will stop producing lower frequencies. In a three-way system, there are two crossover points. One is the Woofer- Midrange point and the other is the Midrange-Tweeter point. Four-way systems add yet another crossover point. The first is the Woofer- Midbass point, then second the Midbass-Midrange point and the third, the Midrange-Tweeter point. When selecting crossover points, make sure that the driver can handle frequencies beyond the crossover point. In other words, the lower the order, the wider the band of frequencies the driver must handle, given the same crossover points. One final note bears mentioning. SpeakerDES allows you to design four 2-way networks. There are couple of points to be made in regards to these. The first involves the differences between the 2-way crossovers. The first network is a standard 1st Order 2-way. However, the last three are 2nd Order 2-way networks. Each has been designed by a different individual and each has it's advantages and disadvantages. The first is the Butterworth filter. It is very basic, providing excellent power characteristics, and smooth response with the exception of the 3 dB peak/dip. The second filter is the Bessel. It provides a good power characteristic, but has a slight peak in response at it's crossover frequency. The third filter is the Linkwitz-Riley. This filter is designed for frequency response smoothness rather than power characteristics. It is noted for a dip in power delivery. The second point about the 2-way networks is the use of reverse polarity. This is used to avoid a null response at the crossover frequency. The price is that your tweeter(s) are 180 degrees out of phase with your woofer(s). This has a negligible effect on the sound of the speaker. ------------------------------------------------------------------------- SpeakerDES Design Approaches ----------------------------- SpeakerDES allows a great deal of flexibility in it's design approaches. That is, based on common and specific criteria, you can design loudspeakers in a variety of situations. Each design approach includes some basic criteria for the loudspeaker design. You must meet all of these during the design process: 1. You must know what final frequency response graph shape you wish to have. 2. You must know which type of enclosure you want to design. 3. You must know what shape the enclosure is to take. The following are the design approaches. Use the one appropriate to your situation and reference this manual when completing the steps: Approach # 1 ------------ Criteria : No particular driver has been chosen. Steps: 1. Choose your enclosure type by selecting the SELECT-Enclosure Type function. 2. If necessary, select a space specification from the LOOKUP-Space Spec or User Space functions. 3. Alter the shape of the enclosure by manipulating the Side View and Front View contact points. 4. Define your frequency response graph shape using the simulated "EQ" in the Response Requirements area. 5. If the variance value is too high, access the SELECT-Frequency Points function and alter the variance. 6. To select the driver(s) to be used in your loudspeaker, select the LOOKUP- Driver Spec or User Driver function. Perform a driver SEARCH and select the most suitable driver. 7. Analyze the design by selecting ANALYZE-Single Graph function. If the graph does not match your frequency response requirements closely enough, you may wish to perform steps #4 and #5 again. You may also wish to experiment with enclosure tuning* (Ported enclosures) or enclosure volume* (Closed enclosures) 8. When the design meets your requirements, you may save it by selecting the FILE Save function, or print a hardcopy of it by selecting the FILE Print function. * See Loudspeaker Design Basics and The SpeakerDES Screen - Specifications Area sections of this manual ------------------------------------------------------------------------- Approach # 2 ------------ Criteria: You have pre-purchased a driver or have a particular driver in mind. Steps: 1. Choose your enclosure type by accessing the SELECT-Enclosure Type function. 2. If necessary, select a space specification from the LOOKUP-Space Spec or User Space functions. 3. Select your particular driver from either the standard or the user driver databases using the LOOKUP-Driver Spec or User Driver functions or directly enter the values in the Specifications area of the SpeakerDES screen. 4. Adjust the Response Requirements "EQ" on the SpeakerDES screen to reflect your desired response curve. 5. Analyze for optimum volume using the ANALYZE-Optimum Volume function. 6. Alter the enclosure shape, using the Front View and Side View contact points, to match the optimum volume required with the enclosure volume. 7. Analyze the design by selecting the ANALYZE-Single Graph function. If it does not match your requirements, try altering the variance using the SELECT-Frequency Points function. Then perform steps #5-7 once again to adjust your design. If these changes do not help, you may wish to experiment with enclosure tuning* (Ported enclosures) or enclosure volume* (Closed enclosures). 8. When the design meets your requirements, you may save it by selecting the FILE Save function, or print a hardcopy of it by selecting the FILE Print function. * See Loudspeaker Design Basics and The SpeakerDES Screen - Specifications Area sections of this manual The SpeakerDES Screen --------------------- The SpeakerDES screen displays and integrates information about the enclosure design, user preferences and current driver data. It is divided into five different parts: 1. The MAIN MENU BAR 2. The SIDE VIEW AREA 3. The FRONT VIEW AREA 4. The SPECIFICATIONS AREA 5. The RESPONSE REQUIREMENTS AREA 1. Main Menu Bar ---------------- This menu bar uses a pull-down menu system and is located at the top of the screen. To access any menu, simply put your mouse cursor on the desired option and click the left button. A menu will be displayed below the option you selected. Move your mouse cursor down until the sub-option you desire is highlighted and then click on it. ------------------------------------------------------------------------- 2. Side View Area Description & Functions ----------------------------------------- This area is used to define what the enclosure will look like from the side. On the left and bottom sides of this area are rulers indicating the height and depth dimensions in inches, respectively. These can be used as a guide when determining the dimensions of the side view. Side View Contact Points ------------------------ Inside the rulers is a square (Representing the startup enclosure side view shape) with four smaller squares, one on each corner. Each of the smaller squares is called a contact point. Each contact point is assigned a label as follows: Bottom-Left contact point is called P1 and is non-moveable. Top-left contact point is called P2 and is moveable. Top-right contact point is called P3 and is moveable. Bottom-right contact point is called P4 and is moveable. To Manipulate Side View Shape ----------------------------- To manipulate the shape of the enclosure side view, you must place the mouse pointer on the desired contact point and press and hold the left mouse button. This picks the contact point "Up." Move the contact point to the position you desire by moving the mouse. When you have finished moving the contact point, release the mouse button to "Drop" it. The calculated lengths between these contact points are displayed on the right side of the side view area. For instance, P1-P2 means the length between the contact points P1 and P2. You will note the line between P3 and P4 is dashed. This is because it indicates the mounting board for the drivers. If you manipulate either P3 or P4, you will also note the change in the front view area. This is because the line P3-P4 is a direct reflection of the front view. Space Specifications & The Side View ------------------------------------ Another feature of SpeakerDES is the ability to use space specifications. Space specifications indicate the maximum size the enclosure can be and still fit within a particular space. The space specifications are displayed in the specifications area, but are also displayed in the side view area via a thin dashed line. It forms a box within the side view area. If you use the space specifications, it is important you don't go outside this thin dashed line. Your enclosure may not fit in the space you intended it to. ------------------------------------------------------------------------- 3. Front View Area Description & Functions ------------------------------------------ The Front View shows how the enclosure will look from the front. As with the side view, the front view also displays two rulers which indicate the dimensions of the front view. Front View Contact Points ------------------------- The front view also has two contact points. They perform the same function as the contact points described in the side view section of this manual. Here are their descriptions: Bottom-Left contact point is non-moveable Upper-right contact point is called Z and is moveable. As previously stated, manipulation of the side view (Contact points P3 & P4) alters the front view's height. Therefore it is only necessary that the front view's upper-right contact point be moveable on a horizontal axis to allow the enclosure width to be specified. The Z value (width) is displayed in the upper- right corner of the front view area. To Manipulate Front View Width ------------------------------ In order to change the width of the enclosure front view, click on the contact point and hold the left mouse button. Move the contact point to the desired location and release the mouse button. Space Specifications And The Front View --------------------------------------- The front view also displays the width space specification. It is a thin, dashed line which runs horizontally across the bottom of the front view, just above the horizontal ruler. The ADD And REMOVE Action buttons --------------------------------- The two action buttons shown in the front view area, above, are used to add drivers to and remove drivers from the enclosure design. These are explained in detail in the SpeakerDES Functions - Basic Functions section of this manual. 4. Specifications Area ---------------------- This area is used to display and edit information about the driver(s) and the enclosure used in your loudspeaker design. Description Of Specifications ----------------------------- File is the name of the design file you are editing. Each time you run SpeakerDES, this will be set to the default NONAME.DES. Driver is the name of the current driver you are using. Diameter is the diameter of the current driver you are using in inches. No. Drivers is the number of drivers currently used in your loudspeaker design. Qts is the total resonant property of the current driver (See Loudspeaker Design Basics - Drivers) Fs is the free air resonance of the current driver (See Loudspeaker Design Basics - Drivers) in Hertz. Vas / Driver is the compliance of the current driver (See Loudspeaker Design Basics - Drivers) in cubic feet. Vas (Total) is the total compliance for the quantity of the currently selected driver, measured in cubic feet. ie. This value is Vas / Driver multiplied by No. Drivers. Now depending on the enclosure type (Ported or Closed), the next specifications will vary as follows: For a Closed Enclosure: F3 is the cutoff frequency for the current driver, measured in Hertz. (See Glossary for definition) Fc is the resonance frequency of the enclosure and driver combination, measured in Hertz. Qtc is the total resonant property of the enclosure and driver combination. For a Ported Enclosure: F3 is identical to above definition. Fb is the frequency the enclosure is tuned to, measured in Hertz. No. Of Ports is the quantity of ports you are using. Length is the length of each port you are using, in inches. (A negative value indicates an impossible port size) Diameter is the diameter of each port you are using, in inches. Following the driver and design values are the space specifications. They are described as follows: Width is the maximum width the enclosure can be (ie. Z can be), in inches. Height is the maximum height the enclosure can be (ie. P2 or P3 can be), in inches. Depth is the maximum depth the enclosure can be (ie. P3 or P4 can be), in inches. Below the space specification display are three pieces of enclosure information. They are: Encl. Vol. is the internal volume of the enclosure you are designing, in cubic feet. Encl. Type is the type of enclosure you are designing, either ported or closed. Encl. Mode is the mode you are designing in, either Normal or Overvolume. ------------------------------------------------------------------------- Editing Data In the Specifications Area --------------------------------------- One of the specification area's main purposes is to allow you, the user, to manually enter or change several of the above mentioned specifications. To do this, you simply click on the number you wish to change, and type your new value. If the value you have entered is too large or too small, SpeakerDES will inform you with a warning window. (Explained in the next section) The following items may be edited: Diameter Height Qts Width Fs Depth Vas / Driver No. of Ports (Ported Enclosures) Fb (For ported enclosures, Diameter (Ported Enclosures) Manual Fb mode only) ------------------------------------------------------------------------- 5. Response Requirements Area ----------------------------- The response requirements area is used to define what you want your loudspeaker's bass response curve to look like. This information can then be used when searching for appropriate driver's for an enclosure of a particular size or for finding the appropriate enclosure volume when a particular driver has been selected. Manipulating The Response Requirements -------------------------------------- Changing the response curve to meet your needs is a fairly simple task. Just like the front and side view areas, this area uses contact points. To change the response curve, click on the desired frequency's contact point and hold the left mouse button. Then move the mouse up or down to move the contact point. Release the mouse button when you have found an acceptable dB for the frequency you are modifying. Realistic Response Requirements ------------------------------- When defining your response requirements, we must be realistic of what we can expect of the driver/enclosure combination. A flat 0 dB response is possible (with some poor results), but more than likely you will end up with a sloped curve dropping off at somewhere around 30-70 Hz. You will find that a smooth, gently sloped curve that levels off at 0 dB often provides the best results. Variance Factor --------------- You may have noticed the "±2 dB" just above the Response requirements manipulation area. This value indicates variance from the specified response requirement that is allowed during searches, etc. ------------------------------------------------------------------------- Warning Windows --------------- When invalid data has been entered anywhere in SpeakerDES, you will see a warning window. These windows are there to inform you of the correct values or of errors which occurred as a result of incorrect information being entered. To close the warning window, click on the action button labelled "Ok". You may then enter a different value. ------------------------------------------------------------------------- SpeakerDES Functions -------------------- The SpeakerDES system, as mentioned earlier, uses a menu bar and pull down menus to access most of it's functions. In this chapter, we'll look at each function in the SpeakerDES system. For clarity, the following scheme is used in this manual to identify each menu category and function within that menu category: The name of the menu category (Which appears on the menu bar) will be shown in large, bold letters: FILE The function's name (Which appears on pull-down menus) will be shown in underlined letters: Load ------------------------------------------------------------------------- FILE Load ----------- The Load option is used to load previously saved design files from disk into SpeakerDES. In order to load a design file, follow these procedures: 1. Select Load from the FILE menu. 2. If necessary, change the path by clicking on it and entering your new path. *** Note: You will get an error message if you enter one of the following: a. Incorrect path name b. Non-existent path name c. Path with no files of the current extension (Normally ".DES") If you get one of the above errors and wish to exit the Load function, press the ESC key. 3. If necessary, change the current extension by clicking on it and entering your new extension. The note above applies here as well. 4. Select a design name from those displayed in the file name box (Left side of the Load window) by clicking on it. You may also scroll through the list of design names by clicking on the arrow action buttons beside the file name box. 5. If you now wish to load the selected file, click the left mouse button again to press the GO action button. 6. If you change your mind and wish to change files, go back to step 1. 7. If you wish to exit the Load procedure altogether, click on the EXIT action button. FILE New ---------- The New function allows you to clear old design information from SpeakerDES's memory and setup the system with defaults. It is not a windowed function, instead it uses a sub-menu. When you select New from the FILE menu, you will be presented with two choices: Save Current Design and Clear Workbench. If you select the first, you can save your design before clearing it from SpeakerDES. For instructions on saving your designs, start at step 2 on the next page. If you select the second, the workbench will be cleared. ------------------------------------------------------------------------- FILE Save ----------- Saving stores your designs on floppy or hard disk for later use and modification. Follow these procedures when saving a design: 1. Select Save from the FILE menu. 2. If necessary, change the path by clicking on it and entering your new path. *** Note: You will get an error message if you enter one of the following: a. Incorrect path name b. Non-existent path name 3. If necessary, change the filename by clicking on it and entering your new filename. The note above applies here as well. 4. To save the file, move your mouse cursor to the GO action button and press the left mouse button. 5. To abandon the save operation, click on EXIT ------------------------------------------------------------------------- FILE Print ------------ The Print function allows you to print your designs to an Epson FX compatible printer, HP LaserJet compatible printer or the screen. In order to print out your designs, you must follow these steps: 1. Select Print from the FILE menu. 2. If you wish, you may enter your design name, your own name and the date so that they will appear on the design printout. To do this, click on the desired user changeable value and enter the appropriate information. (Does not apply to screen print) 3. Turn you printer on, and make sure it is online and stocked with paper. (Does not apply to screen print) 4. If you decide not to start the printout, you can exit the print function by moving your mouse cursor to the EXIT action button and pressing the left mouse button. 5. If you wish to start the printout, click on the GO action button. To print to the screen, click on the PRINT TO SCREEN action button. 6. If you are printing out a design and decide to stop printing at some point, click on the CANCEL action button. This will interrupt printing and cancel the print function. ------------------------------------------------------------------------- FILE Save Response EQ ----------------------- This function will save the "EQ" settings in your response requirements area. These settings are then automatically loaded each time you run SpeakerDES. FILE Save Overvolume Mode --------------------------- This function will save the overvolume and wood thickness settings found in the UTILITIES Overvolume Mode function. These settings are then automatically loaded each time you run SpeakerDES. FILE Exit ----------- When you have completed working in SpeakerDES, you can exit the SpeakerDES system by selecting this function. Like the New function, this function has no window of it's own, but rather a second menu. You have two choices: 1. Save Before Exit 2. Exit If you wish to save your work, select the first. If not, select the second. ------------------------------------------------------------------------- LOOKUP Driver Spec/User Driver -------------------------------- SpeakerDES comes ready to work with a database of almost 500 different drivers. Accessing that database is the job of the Driver Spec function. Initial Procedures ------------------ In order to use this function, you must follow these initial procedures: 1. Select Driver Spec or User Driver from LOOKUP menu. 2. If there is any particular brand of driver you wish to lookup, you may click on the Search Key value and enter a new brand. This will cut down the list of choices to only the brand or search key you specify. You can revert back to the entire database listing by replacing the brand you entered with an "*". 3. If there is any particular diameter you wish the driver to be, you may click on the Driver Diameter value. This will cut down the list of choices to only the diameter you specify. You can revert back to the entire database listing by replacing the diameter you entered with a "0" (Zero). Selection Method ---------------- Once you have decided which drivers in the database are eligible for selection, you can proceed to the next step in the selection process called the "Method". Simple Driver Selection ----------------------- If you simply want to select a specific driver (eg. Pioneer 10 Sub), you would have to follow the next steps: 1. Use the scrolling arrows to scroll down to desired driver. 2. Click on the highlighted driver you wish to select. 3. You will note that the mouse cursor was moved to the GO DR1 action button. This action button is used to select driver #1 for use in SpeakerDES. Click on the GO DR1 action button to confirm your choice. You will also note that there are two "GO" action buttons in this function. You may use GO DR2 if you are going to compare the response results of two drivers. If you select GO DR1, you are selecting, as mentioned above,driver #1. If you select GO DR2, you are selecting driver #2. 4. If you wish to exit this function (And not select a driver), click on the EXIT action button. Driver Search ------------- One of SpeakerDES's most valuable functions is it's ability to search through it's databases to find drivers which match the response and volume requirements set down by you, the user. If this is the type of selection method you wish to use, follow these procedures: 1. Make sure that the modifications to the response requirements curve are realistic. 2. Make sure you have followed initial procedures, as listed above. 3. Click on the SEARCH action button. The SEARCH action button will turn red, indicating the start of the search function. Now, you must enter the number of drivers you wish to place in your enclosure. This is done in the user changeable values box "Search Qty". The system will search through the database, attempting to find the correct drivers, based on the quantity, the enclosure volume, and the requirements curve you specified. If the system cannot find any drivers which meet your requirements, you will see the message "No Drivers Found." In this case you will have to make changes to your requirements before trying the search again. 4. To select one of the found drivers, highlight it and click on it.. 5. Click on either GO DR1 or GO DR2, depending on which position you prefer the selected driver to be in (Driver#1 or Driver#2). 6. If you wish to exit this function and not select a driver, click on the EXIT action button. Driver Codes ------------ The drivers used in SpeakerDES contain a value called Model/Class. You will notice this value in the driver display box (right side of lookup window) when scrolling through a list of drivers. The first part of the value is usually the manufacturer's model number for that driver. The second part of the value is the class code. Here are the class codes: W Woofer SW Subwoofer MI Musical Instrument SR Sound Reinforcement FR Full Range MB Mid-Bass DVCMB Double voice coil Mid-Bass MR Mid-range DVCW Double voice coil woofer DVCSW Double voice coil sub-woofer SHLD Shielded Some drivers may have more than one class code, indicating a mix of both classes. ------------------------------------------------------------------------- LOOKUP Space Spec/User Space ------------------------------ As was mentioned earlier, space specifications are used to show you the maximum dimensions the enclosure the can be without being too large for a particular space. The space specifications provided with SpeakerDES are for automobile locations. As well, double checking the measurements with your application is a good idea, especially when designing a none rectangular/cube- like enclosure. 1. Select Space Spec or User Space from the LOOKUP menu. 2. If you wish to select only a certain model year or vehicle brand, click on the Search Key value and enter a new value. To revert back to the entire database of space specifications, replace the model year/brand you entered with an "*". 3. Use the arrow action buttons to scroll through the available list and locate the desired space spec name. 4. To select the space spec you want, highlight it and click on it. 5. If you decide not to select a space specification, you may exit this function by clicking on the EXIT action button. 6. To accept your choice of space specification, click on the GO action button. ------------------------------------------------------------------------- ANALYZE Single Graph / Comparison ----------------------------------- The Single Graph function is designed to graph a single driver (Driver #1). Frequency response is graphed over a range of 0 Hz to 180 Hz. The Comparison Graph function below, is designed to graph both selected drivers (Driver #1 & Driver #2). Frequency response is graphed over a range of 0 Hz to 180 Hz. The Ok action button is the only action button in this window. Click on it to exit this function. ------------------------------------------------------------------------- ANALYZE Optimum Volume ------------------------ This function will find the optimum volume for a quantity of drivers, given your response requirements area curve, response variance and enclosure type. Here's how to use the function: 1. Check your response requirements area curve to make sure it is correct. Also adjust your variance via the SELECT - Frequency Points function if necessary (Remember: The higher the variance value, the less accurate the optimum volume and vice-versa). 2. The function window will display your first driver's name and ask you to enter the quantity of drivers you would like the analysis to take into account. Type in a value from one to nine and press the ENTER key or press the left mouse button. Press the ESC key to exit this function. 3. If you have two drivers selected (Driver #1 & 2), you will perform procedure #2 again, but this time for the second driver. 4. The optimum volume will be calculated for the driver(s). 5. Click on the action button Ok to close the window and exit the optimum volume function. This function resembles the LOOKUP - Driver Spec/User Driver function in that if the search demands are too great, the best can't be found. If no optimum volume can be found, you will see the message "No Optimum Volume Found For Specified Parameters." In the above case where no optimum volume can be found, the Optimum volume function will attempt to provide a recommended enclosure volume. This will be displayed below the "No Optimum Volume..." text. ------------------------------------------------------------------------- ANALYZE Advisor ----------------- The Advisor function provides you with information about the state of your current driver and enclosure. Much like it's namesake, the Advisor function suggests changes to the loudspeaker for better performance. These changes can then be made to effectively improve your loudspeaker design. To use this function, simply read each page of the advisor text and click on the NEXT PAGE action button to bring up the next page. ------------------------------------------------------------------------- UTILITIES Modify User Driver ------------------------------ While SpeakerDES's standard database encompasses quite a selection of popular drivers, it is inevitable that some were missed. So, should you come across a driver which is not listed in the standard database, you can use the Modify User Driver function to add, edit and delete drivers from the custom database. Adding A Driver --------------- To add a driver to the database, you must do the following: 1. Select Modify User Driver function from UTILITIES menu. 2. Make sure you've got the critical specs. Those being name, diameter, Qts, Vas, and Fs. The other specs are purely optional, but helpful. 3. Click on the ADD action button to initiate the add procedure. ** Note all drivers are sorted by name. 4. Enter each user changeable value. When entering the driver name, use double digits to describe diameter. For instance, if I enter "XYZ 5" as a name, it would be sorted to the "XYZ 50" position. Use "XYZ 05" instead. If you make an error while entering the new driver's data, you have two possible courses of action. You can abandon the add procedure by following step#5 below OR you can make a note of the value in error, complete adding the other information and finally return to that driver and edit it using the editing guidelines below. 5. If you wish to abandon the add procedure, press ESC. 6. If you wish to exit this function, click on EXIT. ------------------------------------------------------------------------- Deleting A Driver ----------------- To delete a driver from the database, you must do the following: 1. Select Modify User Driver Function from UTILITIES menu. 2. Use the arrow action buttons to scroll down or up to the driver you wish to delete. 3. Once the driver you wish to delete is displayed, click on the DELETE action button to delete it. 4. If you wish to exit this function, click on EXIT. Editing A Driver ---------------- Editing a driver is an easy procedure: 1. Click on the user changeable value you wish to change. 2. Type in new value. If you decide you don't want to change the value, you can exit the editing procedure by pressing ESC. 3. Press ENTER or left mouse button to enter new value. 4. If you wish to exit this function, click on EXIT. *** Note: You will receive an error message reading "No User Driver specs are present" when you first access the Modify User Driver function. This is okay. Simply click on the warning window's "Ok" action button to close it. You may then continue. ------------------------------------------------------------------------- UTILITIES Modify User Space ----------------------------- SpeakerDES's standard space specifications database contains a number of the more "Sporty" 1992 automobiles available. However, you may have vehicles from past years and newer vehicles which are not listed in the standard database. You can use this function to add, delete or edit those vehicles to the custom space specifications database. Adding A Space Specification ---------------------------- To add a space specification, follow these procedures: 1. Acquire fairly accurate measurements, making sure they fit within the area intended, and that a finished enclosure will be easily put into it and removed. 2. Select Modify User Space function from the UTILITIES menu. 3. Click your mouse on ADD action button. 4. Enter each of the user changeable values in the space record. If you make a mistake while adding space specifications, you have two courses of action. You can either abandon the specification you are entering by pressing the ESC key or you can continue entering the rest of the space specification, and later edit it using the editing procedures, described below. 5. If you wish to exit the Modify User Space function, click on the EXIT action button. Deleting A Space Specification ------------------------------ Deleting space specifications is quite simple: 1. Select Modify User Space function from the UTILITIES menu. 2. Click on arrow action buttons to scroll up or down to the space specification you wish to delete. 3. When the space specification you want to delete is displayed, click on the DELETE action button. 4. To exit the Modify User Space function, click on the EXIT action buttons. Editing A Space Specification ----------------------------- Editing space specifications is also a straight forward type of procedure. Follow these three steps: 1. Select Modify User Space function from the UTILITIES menu. 2. Click on the user changeable value to be changed. Type a new value. Should you decide not to change the value, you can exit the editing procedure by pressing the ESC procedure. 3. If the new value is acceptable, press ENTER or press left mouse button. *** Note: You will receive an error message reading "No User Space Specs Are Present" when you first access the Modify User Space function. This is okay. Simply click on the warning window's "Ok" action button to close it. You may then continue. ------------------------------------------------------------------------- UTILITIES Crossover Design ---------------------------- The crossover design function allows you to easily create passive, parallel crossover networks. It is composed of two function windows. The left window contains the action buttons, crossover selections, driver impedances and crossover point(s). The right window is used to display the current crossover schematic you are designing. The procedures for designing a crossover are as follows: 1. Select the Crossover Design function from the UTILITIES menu. 2. Select the crossover type you wish to design by clicking on the circle beside the crossover type's name. 3. Now, you will have to enter each of the crossover points in your network. Click on the crossover point value you wish to enter and type in the frequency. Press ENTER or the left mouse button to confirm. Press ESC if you wish to exit the editing procedure. To remind you of where these points will be in relation to your driver types, there are lines running to the crossover point entry box(es). 4. All that remains to be entered are the driver impedances. To do this click on the driver's impedance value box and enter that driver's impedance. Press ENTER or the left mouse button to confirm. You may press ESC to exit the editing function. 5. The crossover network schematic should be displayed in the right window at this point. You may wish to make a hardcopy of this schematic. To do so: a. Turn your printer on. b. Make sure it has sufficient paper available. c. Make sure it is online. d. Click on the PRINT action button. 6. You can continue to change the crossover type and frequency points if you wish, or you exit the Crossover design function by clicking on the EXIT action button. ------------------------------------------------------------------------- UTILITIES Compare Drivers --------------------------- Because only part of one driver's information can be viewed at a time on the standard SpeakerDES screen, you may wish to use the Compare Drivers function. It displays information about one or both selected drivers. To exit this function, click on the Ok action button. ------------------------------------------------------------------------- UTILITIES Convert Metric -------------------------- The Convert Metric function converts litres to cubic feet and vice-versa. It also converts millimetres to inches and vice-versa. Using this function is fairly simple. Here's how: 1. Select the Convert Metric function from the UTILITIES menu. 2. If your measurement is a length measurement, click on the Length action button. If it is a volume measurement, you may click on the Volume action button. 3. Next, you must click on the user changeable value box next to the desired units you are using (For volume, either litres or cubic feet. For length, millimetres or inches). Type in the value you wish to convert and press ENTER or the left mouse button. 4. You can continue to enter values, but should you wish to exit this function, simply click on the Ok action button. ------------------------------------------------------------------------- UTILITIES Overvolume Mode --------------------------- Use of the Overvolume function can add considerably to the accuracy and real world performance of your loudspeaker. By taking into account the wood thickness used and the need for bracing, the overvolume function can alter the internal volume, to make it more realistic. Wood Thickness is important for the final design, as cutting angles and dimensions are based on this information. SpeakerDES uses a single construction method which is simple, yet effective. This construction method is reflected in the Overvolume function. To set the Overvolume Mode to On or Off, follow these steps: 1. Select the Overvolume Mode function from the UTILITIES menu. 2. Enter the exact thickness of the lumber you are using into the Wood thickness user changeable value. 3. Click on the circle below the words On/Off to turn overvolume mode on. Click on the darkened circle again to turn it off (Should you not wish to use it). 4. Click on the Ok action button to exit this function window. SpeakerDES will now automatically compensate for the lost volume. ------------------------------------------------------------------------- UTILITIES Screen Saver ------------------------ The Screen Saver function allows you to adjust the delay in minutes before the screen saver is activated. The actual screen saver will scroll the name SpeakerDES around the screen until you move the mouse. To adjust the delay, click on the green bar within the function window. Hold the left mouse button down and move the mouse left or right. Release the button when a sufficient delay has been reached. To exit this function, click on the Ok action button. ------------------------------------------------------------------------- UTILITIES Clock ----------------- The Clock function displays the current time, according to your computer's internal clock. To exit this function, click on the Ok action button. ------------------------------------------------------------------------- SELECT Enclosure Type ----------------------- The Enclosure Type function allows you to select which enclosure type you wish to design. To change enclosure types: 1. Select Enclosure Type from the SELECT menu. 2. A sub-menu will appear. Select either Closed or Ported. 3. If you selected Ported, you will be shown yet another sub-menu. You must select either Auto Fb or Manual Fb. Auto Fb lets the SpeakerDES system calculate enclosure frequency based on the drivers and volume (In this case, both Fb and Port length will change). Manual Fb allows you to enter a fixed enclosure frequency (Port length will be the only affected value.) If you selected Manual Fb, you will notice the flashing cursor beside the letters Fb in the specifications area. Type in your desired enclosure frequency. Click the left mouse button or press ENTER to confirm. Regardless of your last sub-menu select, you must enter the number of ports you wish to mount in the enclosure, and their diameter. All ports in SpeakerDES are assumed circular. Type in these values when the flashing cursor is beside each one. ------------------------------------------------------------------------- SELECT Frequency Points ------------------------- This function allows you to change the band of frequencies and variance the response requirements "EQ" uses. The response requirements area's "EQ" has several frequencies displayed across it's horizontal axis. The defaults are 40, 60, 80, 100, 120 and 140 Hertz (Hz) As well, there is another value, the variance, with a "±" value displayed above the "EQ" The default is ±2 dB. Varying these frequencies allows you to adjust your analysis to a different band of frequencies (Higher, lower, larger, smaller). In addition, altering the ± dB value allows you to adjust to the variance from the settings of the "EQ." To alter these frequencies: 1. Select Frequency Points from the SELECT menu. 2. Each of the current frequency points will be displayed within the function window. You will note they are identical to the "EQ" in the response requirements area. Enter new values to adjust the desired points. Press the left mouse button or ENTER to confirm values or skip values. An explanation of the variance may be in order. Think of the settings on the "Response Requirements EQ" as target values. The variance value says, it's OK to allow values plus or minus "X" amount from the targets I have set. When SpeakerDES performs a driver search, it checks to see if any of the drivers in the database fall within those variances. If a driver matches all six frequency settings plus or minus the variance, it is selected as a candidate. A simple rule to keep in mind about variances: The greater the variance value, the less accurate the search, and the more candidates selected. ------------------------------------------------------------------------- SWITCH ------ When you have selected both SP1 and SP2 drivers, only one can be displayed at a time. This function exists to allow easy switching between SP1 and SP2 drivers. To perform the switch, click on the menu name SWITCH on the menu bar. ------------------------------------------------------------------------- HELP ---- SpeakerDES comes standard with a context sensitive on-line help system. This system can only be solicited from any menu or function. For example, if you are using the LOOKUP Driver Spec function, you can't use the help system. You must first exit. To use the help function, press the right mouse button. This will pop up a help menu (when right clicking on the main screen) or a topic window (for the function you are currently highlighting in a menu or using. If you see the help menu, select the area which you need help in by clicking on the highlighted option. To exit help, click on the option "EXIT Help." The help text on the selected area will be displayed. To scroll up or down through the help area, click on the up or down arrow action buttons. To exit viewing the help information, click on the Ok action button. ------------------------------------------------------------------------- Glossary Bass A term referring to low-frequency sound (20 Hertz - 500 Hertz) Bass is reproduced by woofers, subwoofers, and sound re-inforcement drivers. Bump In a frequency response graph, a bump is represented by a band of frequencies which are greater than 0 decibels (0 dB) Capacitor An electronic component which when used in an audio circuit, filters out frequencies below the capacitor's fixed frequency. Dip In a frequency response graph, a dip represents a band of frequencies which are less than 0 decibels (0 db) Driver The combination of a structural skeleton, cone, voice coil and magnet. The driver receives a varying amplified current, that is used to move it's cone at a variety of frequencies to reproduce sound. Enclosure The hollow cabinet used to trap negative sound waves and dampen driver cone movement. Every driver produces negative sound waves to some extent. These waves cancel the positive sound waves that we want to hear, causing a loss of sound level. As well, many drivers require the damping an enclosure provides in order to avoid over- extending the cone's surround and and to avoid "bottoming" the driver. F3 A parameter used in loudspeaker design which indicates the frequency where the frequency response curve is down -5 decibels (dB) Fb A parameter used in ported loudspeaker design which indicates the frequency the enclosure is tuned to. Fc The resonant frequency of a closed loudspeaker. Frequency The measurement of how a driver performs in a Response particular range of frequencies. Fs A Thiele-Small parameter indicating a driver's resonant frequency, the frequency where the driver, when held in the open air, vibrates with the greatest movement. Inductor An electronic component, which when used in an audio circuit, filters out frequencies above the inductor's fixed frequency. Loudspeaker The combination of driver(s) and enclosure used to reproduce sound. Mid-Bass A driver used to reproduce frequencies from 250 Hertz to 2500 Hertz. Mid-Range A driver used to reproduce frequencies from 350 Hertz to 7000 Hertz (7 KHz). Optimum The enclosure volume, analyzed with a specific driver, Volume which will most closely reproduce a desired frequency response curve. Order In electronic crossovers, a term used to define the crossover's cutoff rate. The higher the order, the steeper the cutoff slope. Path An MS-DOS term which describes the "path" to get to a file or files. For instance, "C:\SPKRDES\DESIGNS" is interpreted as: "C:" means the hard drive "\SPKRDES" means the SpeakerDES directory "\DESIGNS" means the design directory within the SpeakerDES directory. Port A "Pipe-like" component of ported loudspeakers, the port is used to provide a second resonance which enhances bass output. Qtc The total "Q" for a closed loudspeaker. Qts The total "Q" of a driver. Variance In SpeakerDES, variance provides upper and lower deviation limits from the user's response requirements. It is used during seaches and optimum volume calculations. Vas A Thiele-Small parameter which defines what volume of air provides equivalent resistance to the driver's cone movement. Subwoofer A driver used to reproduce very low frequencies, typically in the range of 20 Hertz to 200 Hertz. Three-Way A term used to describe a loudspeaker with three different types of drivers (ie. Woofer, Mid-range and Tweeter) Two-Way A term used to describe a loudspeaker with two different types of drivers (ie. Woofer and tweeter) Woofer A driver used to reproduce low frequencies, usually in the range of 30 Hertz to 2000 Hertz. Workbench Is a combination of the user's design and the SpeakerDES tools. Clearing the workbench clears out the current design and SpeakerDES's temporary parameters.