WinSpeakerz v2.1 Demo Manual

1.0 About WinSpeakerz, The Speaker Design Toolbox

Welcome to a new generation of loudspeaker design tools! WinSpeakerz is a 32 bit application written for Windows 95. We've taken full advantage of the Windows 95 interface to provide you with a toolbox containing everything you need to design state of the art loudspeakers. And it's never been easier! Just as a pilot can polish his aviation skills using a flight simulator, speaker designers can polish their skills using this loudspeaker simulator.

WinSpeakerz predicts the performance of a loudspeaker system before the system is actually constructed. You can perform unlimited 'what if' simulations by varying box sizes and tuning frequencies. The result? Highly optimized speaker enclosures, even on the first try.

1.1 Loudspeakers and The Signal Chain

We encounter audio systems every day. At the drive-up window, watching TV, on the phone. Even your computer has an audio system. Not to mention your stereo. There is a loudspeaker at the end of the line at each of these audio systems.

The loudspeaker is the limiting factor in the sound quality of all these systems, with rare exceptions. This places the loudspeaker in the role as final arbiter of sound quality of just about every audio system we encounter.

In the largest sense, an 'audio system' would include everything in the path between the original audio event and the ear of the listener. This starts with the acoustic environment of the event, the microphone, mixer, recorder, etc..all the way up to your favorite CD. At the back end of the signal chain your CD player recovers the signal and converts it from the digital domain to the analog domain where it is transferred, with great accuracy, to your power amp and ultimately presented to your speakers for the launch of an acoustic waveform into the room and toward your ears.

Audio designers refer to this grand path as the 'signal chain'. Like a real chain, the signal chain is only as strong as it's weakest link. The weak links in the signal chain are at each end: the microphones and the speakers. When we consider the equipment path that connects our ears with the musicians we hear on our favorite CD's, we see a complex chain of gear which ends with the speakers in our listening room. Our loudspeakers are probably the single most critical link in the complete signal chain.

1.2 The Audible Frequency Range

Audio is defined by the range of acoustic vibrations (measured in Hertz) which are audible to us humans as sound. The range of human hearing is normally considered to be from about 20 Hz to 20k Hz. The frequencies of pianos, keyboards, guitars, other musical instruments, and the human voice fall within this audible range.

Figure 1: Frequency Range of Human Hearing

Our goal in designing loudspeakers is to create systems that accurately reproduce the full range of frequencies that are audible to the human ear. Ideally, we would like to have a loudspeaker play at the same loudness regardless of the pitch (frequency) of the sound.

Unfortunately, real loudspeakers can only stay flat for so long as pitch is reduced. Loudspeakers are limited in how low they can go and the frequency response curve shows you visually how low the speaker does go. We'd like for the curve to remain flat for as long as possible as it goes from right to left, but at some point it will roll off and pass through the F3 point and we will start losing bass. That is, the frequency where the response is down 3dB. We want to design an enclosure with the F3 as part of the design criteria. Now let's explore some frequency response curves for the driver in the WinSpeakerz demo.

Figure 2: A Typical Frequency Response

2.0 Using WinSpeakerz

Let's begin by launching the WinSpeakerz Demo. Once you have launched WinSpeakerz you will see the three windows displayed on the screen as shown below. This trio of windows act as a workbench where you can try out an unlimited number of new designs.

Figure 3: The WinSpeakerz Workbench

The Plot window is the large upper window where the Frequency, Excursion, Phase, Delay and Impedance Responses are displayed.

The Driver and System Parameters window (bottom left) displays the basic parameters of the driver. The Driver and System Parameters window is where you specify the number of drivers in the enclosure. SPL (Sound Pressure Level) is given for any number of drivers at any input power and any listening distance. The complete list of driver parameters is shown in the System Editor window.

The Box window (bottom right) is where you describe the box type you want WinSpeakerz to analyze. When you select a box type from the Box menu the Box window will be redrawn for your selected box type.

An icon at the top left of the Box window shows at a glance the type of box you are working with. WinSpeakerz allows you to design the following box types:

^{2nd Order Closed Boxes}

^{3rd Order Closed Boxes}

^{4th Order Vented Boxes}

^{4th Order Bandpass Boxes}

^{5th Order Bandpass Boxes}

^{6th Order Bandpass Boxes}

^{Additionally you can:}

         Specify any number of identical drivers in your enclosures

         Design Isobarik (or Compound) enclosures

2.1 Driver Evaluation in Closed Boxes

Frequency Response

The Frequency and Excursion Responses are always actively selected as a default when you launch WinSpeakerz.

All Response curves can be toggled off from the toolbar or under the Analysis menu. For this section of the tutorial toggle off the Excursion Response so that we can explore the frequency responses of the enclosures we design. We'll toggle the Excursion Response on later in the tutorial.

         Toggle off the Excursion Response from the toolbar.

         Under the Box menu select '2nd Order Closed Box'.

We will start the Closed Box evaluation by finding the smallest enclosure that would be of interest for this driver and then explore progressively larger boxes. We'll be working with the Box Volume, V(B) and the Closed Box Q, Q(tc) fields. These fields are interactive. Enter one and the other is calculated.

Figure 4: The Closed Box Q field, Q(tc)

Let's talk about the Closed Box Q, Q(tc), field. The Q(tc) delivers a predictable frequency response. For example, if we enter a Q(tc) of .707 we will get the flattest frequency response possible for this driver. But first, we need to take into consideration that the Total Driver Q, Q(ts), for this driver (located in the Driver and System Parameters window) is .49.

Notice what happens to the box size as you enter the following Q(tc)'s:

         Enter a Q(tc) of 1 in the Closed Box Q field. This gives you a Box Volume of 1.00 cu ft. (small box)

         Enter a Q(tc) of .7 in the Closed Box Q field. This gives you a Box Volume of 3.05 cu ft. (box size triples)

         Enter a Q(tc) of .5 in the Closed Box Q field. This gives you a Box Volume of 77.08 cu ft! (huge box)

         Enter a Q(tc) of .49 in the Box Volume field. This gives you a Box Volume of 0. (The box has become infinitely huge and is not feasible)

The most significant Closed Box Q's are shown below. We will use them as our guideposts for our closed box design. Note that you are not restricted to these alignments when you design an enclosure, they are intended only as guideposts.

         Q(tc) = 1.0 This frequency response corresponds to the smallest box of interest. It has a slightly peaked

response.

         Q(tc) = 0.707 This is a Butterworth alignment which has the flattest possible frequency response.

         Q(tc) = 0.577 This corresponds to a Bessel alignment which has the flattest possible Delay Response.

         Q(tc) = 0.50 This corresponds to a Critically Damped alignment in which the step response has no

overshoot. It requires the largest box.

Figure 5: Frequency Responses Corresponding to Significant Closed Box Q's

The smallest useful enclosure for a given driver is usually a closed box with a Q(tc) of about 1.0. That's because smaller closed boxes would have Q(tc) values greater than 1.0 and therefore, would have an excessively peaked frequency response for music reproduction.

         Enter the value 1.0. in the Closed Box Q, Q(tc) field in the 2^nd Order Closed Box window.

Figure 6: Closed Box Q(tc) = 1, Box Volume V(B) = 1.0042

         Note that the program has calculated and displayed the Box Volume of 1.0042 cubic feet that corresponds to a Closed Box Q(tc) = 1.

         Select Calc Freq Resp under the Analysis menu. (or use Ctrl+F from the keyboard)

As expected, this response is slightly peaked at 1.5dB. Note that the F3 or -3dB cutoff, is about 65 Hz.

Before going any further, we should save this response curve in one of the 10 System files.

         Select Store workbench in Sys1 under the Display menu. (or use Alt+1 from the keyboard)

We can extend the bass response by looking at larger boxes. We'll lower the Q(tc) and use the Butterworth alignment of .707 to get a larger enclosure.

The Butterworth alignment gives the flattest and most extended frequency response possible for a closed box speaker system, making it the first choice for many designers. To make the Butterworth alignment with a Q(tc) of 0.707, we need a larger box compared to the 1.0 cubic feet that is required for the system with Q(tc) of 1.0. As we increase the Volume of the Box, the Closed Box Q will fall.

         Enter 0.7 in the Closed Box Q edit field in the Box Parameters window.

The system calculates and displays in the Box Volume edit field the volume required for the Butterworth system: 3.0537 cubic feet. Note that the box size tripled. Calculate the frequency response and save that response in System 2.

         Select Calc Freq Resp under the Analysis menu (or use Ctrl+F from the keyboard).

         Select Store workbench in Sys 2 under the Display menu (or use Alt+2 from the keyboard).

Look at the frequency response and you'll see that it makes a maximally flat Butterworth response. The F3 has gone down from about 65 Hz to 58 Hz and has a usable low end (-10dB) of about 35 Hz. This would make a good closed box loudspeaker system for the TA Model 8.

Figure 7: Q(tc) = .7, V(B) = 3.0537

2.2 Saving and Recalling System Files

Now that you have some plots on screen and saved into System files you can try the system save and recall feature. First, clear the plot window.

         Select Clear Display under the Display menu. (or use Ctrl+E from the keyboard)

         The system clears the plot window display. Now recall the first of the two plots.

         Select Recall System 1 under the Display menu. (or simply press the Sys 1 button on the toolbar)

         Repeat this step to recall System 2.

Each time you recall a plot from a System file the Box Parameters window will be refreshed with the contents of the file saved for that System. When you save a System file, only the response curves that have been calculated and that you have currently selected under the Analysis menu will be saved with that System file.

2.3 Creating an Array of Possible Responses

WinSpeakerz can show you an array of possible responses for any driver and save those responses in the 10 System memories. Here is a fast was to see what the driver will do in a vented box:

         Select the 4th Order Vented Box from the Box menu.

         Enter a Box Volume, V(B) = 0

         Calculate the response (Ctrl+F)

2.4 Driver Evaluation in Vented Boxes

Now we will explore some frequency responses for a vented box.

         Select Clear Display from the Display menu.

         Select the 4th Order Vented Box from under the Box menu.

To make a good vented box, you should start with a closed box that has a Q(tc) no higher than 0.7. In general, start with a low box frequency, say 40 Hz, and increase or decrease the box frequency in about 10 Hz steps until you see the range of responses possible for this box volume. Then, fine tune the best of the responses for the flattest response.

We will start with a box Q(tc) of 0.65and try venting it at 35 Hz.

         Enter .65 in Q(tc) field in the Box Parameters window.

         Enter 35 (Hz) at the Box Freq. field in the Box Parameters window.

         Note that the Min. Vent Area, SvMIN has been calculated and displayed in that field.

SvMIN = 6.5 sq inches. This is the smallest vent area that would be free from vent noise.

         Select Calc Freq Resp under the Analysis menu. (or use Ctrl+F from the keyboard)

Figure 8: Q(tc) = .65, V(B) = 4.184 cu ft, F(B) = 35 Hz

You can see that venting the box has extended the low frequency cutoff from 65 Hz for the closed box to 38 Hz for the vented box tuned to 35 Hz. This response is slightly peaked in the 80 Hz region.

         Save this response in System 3. (or use Alt+3 from the keyboard)

We could continue to look at higher box frequencies but they would only result in more peaked responses and higher cutoff frequencies.

Now that we have completed the design for a vented enclosure we can open the Vent Calculator.

         Select the Vent Calculator icon from the toolbar.

We want to choose a vent(s) that will provide the recommended minimum vent area, SvMIN (6.5 sq in) or as close to that as possible. Open the Vent Calculator and you'll notice that WinSpeakerz has recommended using 2 two inch diameter tubes. The vent surface area is 6.283 sq inches and each vent would be cut to 1.251 inches in length.

Figure 9: Recommended number of tubes

         Select OK to go back to the Workbench.

Figure 10: Vent information displayed

         Save the contents of the Box Parameters window to System 3 to store the vent information.

2.5 Using the Excursion, Phase, Group Delay and Impedance Response Functions

Excursion Response

         Toggle the Excursion Response back on.

The Excursion scale is calibrated in millimeters at the right side of the screen. The default scale goes from 0 to 15 millimeters. You can choose the appropriate scale for a given driver. Under the System Editor window we can see that the xmax, or Max Peak Displacement of the TA Model 8 driver is about 9 millimeters.

The Excursion Response represents the movement of the speaker cone. With only 1 Watt of input the cone does not move very much. The Predicted Excursion Response increases with input power just as the excursion (cone travel) of a speaker increases as you turn up the volume. You can view the Excursion Response of a system at any power level you wish by changing the Input Power, P(in), in the Driver and System Parameters window.

We can see that the Excursion Response of this driver at its full rated power, 70 Watts, goes over both the Mechanical and Linear Excursion Limits. We need to derate the system by adjusting the input power as shown below.

Figure 11: Excursion Response with 1 Watt, 50 Watts, and 70 Watts of Input Power

WinSpeakerz gives you information on both the linear excursion and mechanical excursion limits of the driver. The Mechanical Excursion limit is how far the cone physically travels before it hits a mechanical stop. When it hits the mechanical limit it causes a loud, unpleasant noise. There is some risk the driver will be damaged when it hits the mechanical limit. You've probably turned up a radio or TV just a little bit too much and experienced the unpleasant distortion that results. The WinSpeakerz Excursion Response provides a way of predicting how loud a system can be played before you hear distortion.

Linear Excursion is the nominal xmax that manufacturers quote on their drivers. It's the furthest the cone can travel without distortion. Specifically, it's the furthest the cone can travel without the voice coil beginning to come out of the gap. Linear Excursion is how far it can travel without distorting.

Phase Response

         Toggle off the Excursion Response from the toolbar.

         Toggle the Phase Response on.

The Phase scale is on the left side of the screen. The default Phase scale is calibrated from 0 degrees to 450 degrees in 30 degree increments. Each grid step is 30 degrees.

At high frequencies the input and output of a speaker system are in phase. At lower frequencies the output shifts to a different phase angle from the input. Ideally, in a perfect loudspeaker, the output would always be an exact reproduction of the input. However, in general the output phase of a speaker system is different from the input. Phase Response, per se, is generally inaudible to the humans ear but Phase Response becomes very important when you combine signals such as the outputs of a woofer and a tweeter. We want to know how they combine and add in the crossover region because accurate summing at the listening location depends on the Phase Response of each driver. If they happen to be 180 degrees out of phase they will subtract and you will get a notch at that frequency.

Figure 12: Typical Phase Response

Delay Response

         Toggle off the Phase Response

         Toggle on the Delay Response

The Delay scale is calibrated in milliseconds and is displayed on the right side of the plot window. The calibration scale can be adjusted under the Analysis menu. The default setting at startup is 30 msec.

Group Delay Response represents the system delay time. It's the delay of the signal from the system electrical input to the speaker's acoustic output.

Group Delay is important because we don't want any perceptible differences in time delay among the various frequency components of our program material. If the time misalignment or 'time smear' is bad enough it will be audible. At high frequencies there is virtually no delay. As you go down in frequency the delay increases near the cutoff frequency.

Figure 13: Typical Delay Response

Impedance Response

The Impedance scale is displayed at the right side of screen in ohms. Calculate the response by doing a Ctrl+G.

The shape of a loudspeaker's impedance curve reveals much about a speaker. For example a closed box speaker system will have an Impedance Response with a single resonance peak. A Vented box will have two peaks.

The Impedance Response represents 'resistance' if you will, as a function of frequency. An ideal Impedance Response would be a nice flat line at the nominal impedance of the speaker. In fact, most real world loudspeakers do not have a flat Impedance Response. Typically a woofer system will have an impedance peak at the systems' low frequency resonance or two peaks in the case of a vented box. At higher frequencies the speakers impedance will increase due to the effect of voice coil inductance.

The shape of the impedance peak implies the Q(tc) of the system. For a high Q system, say 3 or more, the impedance peak will be narrow. A system with a Q of 1 would have a wider, more rounded impedance peak. A Q of .5 will have a relatively broad impedance peak.

Figure 14: Typical Impedance Response

Note that we were able to adjust the frequency end points in the plot window in order to see both peaks. You can explore this feature by selecting High Freq and Low Freq limits under the Display menu.

2.6 The WinSpeakerz Driver Database

Driver (transducer) selection is a critical step in the speaker design process. WinSpeakerz includes a powerful search and sort Driver Database with approximately 1,000 drivers included. You'll find about 60 different driver manufacturers including JBL, EV, Vifa, Dynaudio, Fane, Focal, Alpine, and Rockford Fosgate. Of course you can add new drivers to your Driver Database by entering the basic Thiele Small parameters.

From the Driver Database you can search for drivers that meet your specific requirements for a project. For example, your next project might be for a home theater system and you're interested in 10' drivers with an SPL of 92. You can instruct the Database to show you just those drivers that are10 inches in diameter with an SPL of 92.

You can also specify how your selection of drivers is to be sorted. The default sort is by Manufacturer and Nominal Diameter. However by making another selection in the pull down 'Sort' list the selected drivers can be sorted by free air resonance, price, or any other combination of parameters. Designers can edit existing driver data, add new drivers, and delete drivers from the Database.

Double-clicking on a driver in the listing opens the Record Editor where driver data can be edited. Each driver record in the Database has space for up to 98 parameters displayed on three pages: General Information, Parameters, and Physical and Mounting Information.

Figure 15: The WinSpeakerz Driver Database

2.7 The System Editor

The System Editor comes into play after you've selected a driver and have started working at the Workbench. In order to see the full details of the System currently on the Workbench you open the System Editor by selecting 'Edit System' under the Edit menu (or at the toolbar). The System Editor is the place to make adjustments to various system parameters (such as box loss Q, isobaric factor, R(e), etc.), write notes on the system as well as make custom adjustments to this System's particular driver.

         Select Edit System from the toolbar (or Edit menu).

Figure 16: The System Editor

The System: Details page displays the name of the System File, Demo Speaker Project 1. The tabbed pages of the System Editor include:

         System: Details

         System: Notes

         System: Model

         Driver: General Information

         Driver: Parameters

         Driver: Physical and Mounting Information

On these pages you can change the volume of the box under test, or the box resonance frequency. All the parameters from the Box Parameters windows are saved as part of the Speaker Project File plus any System notes that you might want to enter on the System: Notes page. The tab key will scroll you through the various edit fields as well as your up and down cursor keys.

You may want to create a System that consists of optimum enclosures for various size boxes for a particular driver, and then save that System. When you design with that driver, recall that file and it will already have saved and displayed for you proposed System Responses for different size boxes.

Figure 17: A Project File

Each of the 10 System memories contains all six pages of information, all of this in a single Project file.

         Close the System Editor window by clicking on its close box at the top right.

This will take us back to the plot window.

         Print your report by doing a Ctrl+P.

The print command will allow the user to print a normal report for the TA Model 8 driver. Included in the printout is an expanded listing of the parameters shown in the Driver Parameters window, the contents of the Box Parameters window, and the System parameters.

2.8 The Vent Calculator

The Vent Calculator has tabbed pages for Tube Vents and Rectangular Vents. The Vent Calculator will recommend the number and diameter of tubes based on the Minimum Recommended Vent area, SvMIN in the Box Parameters window. Or, enter the desired diameter and number of tubes and the vent surface area and length of each tube will be calculated.

For Rectangular Vents enter the vent height, vent width and desired number. The vent surface area and length of the vent will be calculated.

Figure 18: The WinSpeakerz Vent Calculator

2.9 The WinSpeakerz Box Calculators

The Rectangular, Trapezoidal and Bandpass box calculators are also located under the Box Menu and on the Toolbar. There are input fields for Driver Displacement, Bracing Displacement, Other Displacement and Box Volume added by filling. The WinSpeakerz manual goes into much greater detail about each of these features.

In addition to calculating the volume from arbitrary enclosure dimensions, WinSpeakerz will calculate the dimensions from the volume. You can enter box dimensions and the box volume will be calculated, or you can enter a volume and WinSpeakerz will calculate the dimensions using the golden ratio. The Box Calculators have locks in each of the box dimension fields for holding certain dimensions constant while allowing other dimensions to float.

The Trapezoidal Box Calculator includes an angle field to specify the angle of the side of the enclosure. The default is 15 degrees when you first open the trapezoidal box calculator. WinSpeakerz takes the V(B) from the Box Parameters window and calculates the dimensions for a 15 degree trapezoidal enclosure according to the golden ratio.

These calculators have default entries that cannot be changed in this Demo version.

Figure 19: The WinSpeakerz Box Calculators

2.10 The Crossover and Network Calculators

WinSpeakerz also provides specialized calculators which support the design of passive crossovers, attenuators, and impedance compensation networks.

WinSpeakerz has six types of crossover calculators: 1st, 2nd, and 3rd Order Butterworth, 2nd and 4th Order Linkwitz and 1st Order Series with adjustable damping. They all operate in the same manner with the user entering the impedances of the tweeter and woofer and specifying the crossover frequency. The WinSpeakerz Crossover Menu includes a Resonance Compensator Calculator, Inductance Compensator Calculator (Zobel) and a Tweeter Attenuator Calculator.

These calculators have default entries that cannot be changed in this Demo version.

Figure 20: The WinSpeakerz Crossover and Network Calculators

2.11 dB SPL Mode

SPL, or Sound Pressure Level is a measure of the perceived loudness of sound. For example, normal conversation in a room might be around 80 dB. If you were at a very loud rock concert the SPL might be around 120 dB.

WinSpeakerz has two choices for the frequency response scale: 0 dB Mode and dB SPL Mode. While the 0dB scale is normally used to quickly locate the -3dB and -10dB frequencies on the response curve, the dB SPL scale is useful for showing how loud the speaker can play at full power, or at any power level you enter in the P(in) field of the Driver and System Parameters window. This feature is especially useful where it is necessary to derate the system power below the maximum thermal power rating of the driver in order to avoid violating the excursion limit of the driver in a particular enclosure.

When you open the WinSpeakerz application the default SPL distance is 1 meter. Enter values either in meters or feet. When you enter one the other is calculated automatically and the SPL scale is recalculated to reflect that new distance. When you're in the SPL mode the screen will redraw whenever you enter a new value in one of these fields. The SPL can be predicted for any Distance, D, any Number of Drivers, N, and at any subsystem Input Power level, P(in).

Figure 21: SPL at 3.2 ft, 50 Watts of Input Power

2.12 The Preferences Menu

This is where you'll fill in your company information that will appear in the title block of your printed reports.

Selection is provided for metric or English units in the Preferences window. You can also select the file WinSpeakerz will open with. There are 4 choices for the plotting background.

Figure 22: The WinSpeakerz Preferences menu

2.13 The WinSpeakerz v2.0 Manual

A generously illustrated 275 manual is included with the fully functional version of WinSpeakerz. The first half of the manual includes a step by step tutorial for those new to loudspeaker design. The second half of the manual is titled 'Introduction to Loudspeaker Design'. You'll find discussions on Speaker Design Tradeoffs (box size versus efficiency), Compliance Ratio, Driver Evaluation in Existing Enclosures, Driver Parameter Measurement, Crossover Design, Designing Bandpass Enclosures and more!

Part 1: The WinSpeakerz Users Guide

         Getting Started

         About WinSpeakerz

         Using WinSpeakerz

Part 2: Introduction to Loudspeaker Design

         Audio Basics

         Loudspeaker Basics

         Enclosure Design and Construction

         Crossover Design

         Driver Parameter Measurement

         Frequently Asked Questions

3.0 New in v2.0! Automobile/Cavity Modeling

This new feature allows you to see what happens to the frequency response in the bass region when you place a loudspeaker in an enclosed cavity, such as an automobile cabin or listening room. It is important that designers modeling speakers for use in an automotive environment see the combined effect of the enclosure along with the vehicle transfer function.

         Turn the cavity effect modeling on by clicking on the car button on the toolbar.

         Go to the System Editor

         Go to the Model page

         Enter the corner frequency for your vehicle (or room)

NOTE: You can find the corner frequency of YOUR OWN vehicle (or room) using the following formula:

corner frequency = 565/D where D= the largest cabin dimension (Example: 565/8.55 = 66)

Figure 23: Figure 7: Frequency Responses in an Automobile/Cavity

Unlike speaker design programs which model auto cabin effect as a fixed response, WinSpeakerz allows the designer to specify both the corner frequency and the Q of the vehicle transfer function.

3.1 New in v2.0! Diffraction Loss Modeling

Loudspeaker enclosure 'diffraction loss' occurs in the low frequency range of loudspeakers in enclosures that are located in the open, away from walls or other surfaces. The essence of it is this: a speaker radiating into half space plays 6 dB louder than the same speaker radiating into full space. A full range speaker finds itself radiating into half space at the upper frequencies but radiating into full space at lower frequencies. This results in a gradual shift of -6dB from the highs to the lows. This is called the '6 dB baffle step' or the enclosure's 'diffraction loss'. The center frequency of the transition is dependent on the dimensions of the baffle. The smaller the baffle the higher the transition frequency.

All enclosure shapes exhibit a basic 6 dB transition or step in the response with the bass ending up 6 dB below the treble. WinSpeakerz v2.0 can accurately model this bass loss.

Figure 24: Diffraction Loss Modeling On/Off

3.2 New in v2.0! Greater Print Capability

WinSpeakerz v2.0 has added the ability to print the Box Calculators. You can also print a driver listing when the Driver Database is open.

3.3 Additional Features in WinSpeakerz v2.0

         You have a choice of five different dB per division settings. You can set the vertical scale to display either .5, 1, 2, 3, or 5 dB per division. The 1dB step allows for a high resolution plot or you can see a more course resolution plot of the frequency response at 3 dB. The default setting is 2 dB per division. The .5 and 5 dB settings allow you to zoom in to see detail or to zoom out to gain perspective.

         The variable high-low frequency limits allows you to zoom out and see the loudspeaker response in perspective with respect to the entire audio bandwidth or to look closely at a narrow band for greater detail. You may want to set the limits to 20 Hz and 20k Hz to see the response of the woofer system in perspective to the complete audio system. You can set the Low Freq Limit anywhere from 1 Hz to 10k Hz and the High Freq Limit from 10 Hz to 100k Hz.

         WinSpeakerz will show you the range of possible responses for a driver. Turn on those responses you'd like to see from the toolbar. Enter a 0 in the Box Volume field, VB, followed by Ctrl+F.

         The On/Off status of each response is shown under the Analysis menu by the checkmark at the left of the menu item. Only those responses that are selected are actually calculated. The Frequency and Excursion Responses are tuned on as a default when you WinSpeakerz.

         WinSpeakerz can model isobarik (sometimes called 'compound') enclosures. Enter '1' for the number of drivers in the System Editor window. Enter '2' for the Isobarik Factor.

         You have two choices for the frequency response. You can choose between 0 dB Mode and dB SPL Mode which can tell you the dB SPL (loudness) of the proposed system.

4.0 New in WinSpeakerz v2.1!

         WinSpeakerz v2.1 is now fully compatible with the Windows NT Operating System.

Additional Information about this Demo

         You cannot change the parameters of the driver in this demo version.

         You cannot access the WinSpeakerz Driver Database in this demo version.

         You cannot open or save Project files in this demo version.

         The Box and Crossover Calculators will not accept numerical input in this demo version.

This Demo manual was excerpted from the WinSpeakerz manual.

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