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MANUAL FOR DDT3D

VALID THROUGH VERSION 1.651

Welcome to the Danley Design Tool 3D program.

Introduction

DDT3D is a very powerful tool that lets the user visualize how sound propagates from loudspeakers, including subwoofers, and interacts with sound from other speakers and with the room. Working in 3D lets the user model sound systems with great detail and accuracy. DDT3D is not an acoustics simulation program. It does not model the room acoustics, but it will very precisely show the interaction of the loudspeakers with each other and with the seating areas of a room.

Installation

DDT3D comes as a self-‐installing program. Simply click on the icon and it will install. The program requires less than 20 mb of hard drive space.

Getting Started

When you Rirst launch the program you will notice that there are 3 parts to the display. On the left, at the top of the screen there is the Sound Field window. This is where the 3D coverage maps are displayed. You can choose the frequency and the resolution of the display. See the section on the Sound Field window for more information.

Below the Sound Field window, is the Frequency Response window where the frequency response of the system is displayed. The Frequency Response window becomes active when one or more microphones are placed in the sound Rield. The response of up to 10 microphone positions can be displayed at once. See the section on frequency response for more information.

Danley Design Tool 3D

DDT 3D Manual

DDT3D Screen

On the right, there are a number of drop-‐down tabs allowing the user to design the system to model. We call this part the Parameters Window.

Moving the Panels

When you see this symbol you can grab it with the mouse and

move the panel anywhere on the screen. This way you can customize the look of your screen and keep active the tools that you use frequently. To return all panels to the default position click the default panel location button.


DDT 3D Manual

The Top Level Buttons

Moving the mouse over the buttons on the top left of the screen will display a “roll over” description of the function of the button. In the top row from left to right these are:

Create a New Project -‐ start with a clean slate!

Open an Existing Project -‐ opens the Windows Browse window

Open a Recent Project -‐ opens a window with the most recent DDT projects

Save a Project -‐ opens the Naming window and allows the user to save a project.

Window Reset-‐ returns all panels to default positions (see Moving Panels)

Max/Min -‐ toggle sound Rield window from full size to default

Memory -‐ records Sound Field and Frequency Response to one of 3 memories. View using Memory tab.

SPL Buttons-‐ opens a box next to an active microphone and displays the A, C or F weighted sound pressure level at that microphone position.

Units -‐Toggles between feet and meters

In the second row, the buttons are the Sound Field Controls

FullR -‐ renders the coverage map in the highest resolution possible

HiRes -‐ renders the coverage map in High resolution

Mres-‐ renders the coverage map in a Medium Resolution

LoRes-‐ renders the coverage map in a low resolution. Note; the higher the resolution the slower the rendering.

Band Widening -‐ selects the bandwidth of the simulation, either ⅓ or full octave

Frequency-‐ selects the ⅓ octave center for the sound Rield simulation


DDT 3D Manual

The Frequency Response Window

To see the frequency response at any location, or in up to 10 locations, place microphones in the Sound Field. The response will immediately appear in the Frequency Response Window. Move your curser over a response curve. The frequency will appear in the grey box, and the amplitude will appear in the colored box corresponding to the curve.

The Vertical scale can be set using the three buttons directly above the graph display. This feature was added in version 1.651. If your screen does not have these features, please go to danleysoundlabs.com and download the latest version of DDT 3D.

The two buttons directly below the graph are also new as of version 1.651. The smoothing box will perform a ⅓ octave smoothing to all the curves displayed in the window. The button on the left, called refresh rate, lets the user select another form of smoothing which actually reduces the number of points displayed in the graph. The slowest setting displays all the points and is the highest resolution display. The fastest setting , 5, removes a signiRicant number of points from the graph, and is a low resolution display. This speeds up the calculation signiRicantly, at the expense of resolution. The reason for this feature is that if you have a number of microphones active, with many loudspeakers and subwoofers covering numerous audience areas, and you are using smoothing, DDT will slow down to the point of being difRicult to use. The program slows down because of the time it takes to perform the smoothing in real time and keep the frequency response curves dynamic. Of course one way to deal with this slow down is to simply turn smoothing off. If however you must use smoothing, and you have a large complex design, use the slowest setting of refresh rate that you can tolerate. It is strongly advised that you check the system with the refresh rase set to slow, in order to see the most accurate frequency response prediction


DDT 3D Manual

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THE PARAMETERS WINDOW

Camera Tab -‐ The Camera sets the perspective that the user sees for the 3D model.

Subs Tab

Selecting the Subs lets the user place and adjust the parameters of up to 20 subwoofers, by means of Rive sub-‐tabs.

The button with the number in it will turn the sub red for easy identiRication

The check box turns the sub on or off. Off removes the image from the screen

This is a mute button , the image of the sub stays on the screen, but the output is muted. Icon turns red when Mute is activePolarity toggle. Flips the polarity of the sub. Icon turns red when polarity is Rlipped

Grouping Functions

If you look down in the lower half of the Subs window, you will see an entire area devoted to grouping. This is a very powerful and useful tool when designing large, complex sound systems. ( Note: the Speakers tab utilizes the exact same feature)

The box directly below the group pull down box is where the user can give a title or label to a group


DDT 3D Manual

The Group pull down box lets you choose which group of subs you wish to modify. DDT3D supports up to 6 groups. Directly next to the Group pull down box are controls for activating or de-‐activating the entire group, ( a de-‐activated group will disappear from the sound Rield window) muting the group or Rlipping the polarity of the entire group. You can also change the position of a group in the X,Y Z coordinate system, rotate the group around each of the axes, change the gain and the delay to of the group.

Use the + -‐ boxes above and below each of the parameters to increment or decrement that parameter.

The MASTER SUBS lets you change the gain and delay to all subs regardless of the grouping of the subs.

ConRiguration Memory lets you save 3 different conRigurations of subwoofers for easy comparison. Once a conRiguration is saved in memory it can be instantly recalled.

Location

The SUBS/Location tab allows the user to place subwoofers anywhere in the 3D space using an X, Y and Z coordinate system. In the default view, X is left and right, with a positive value to the right. Y is front /back with a positive value towards the front, and Z is the up /down axis with a positive value being up. Under the OPTIONS tabs the user can select to show the coordinates axis in blue, black and red as shown below.

Danley TH118 subwoofer at 0,0,0 showing the X, Y, Z coordinate system


DDT 3D Manual

Rotation Z -‐ setting rotation Z to 0 will point the sub directly along the Y axis.

Inclination X -‐ Inclination is really rotation around the X axis. A negative number will tilt the subwoofer towards the Rloor.

Rotation Y -‐ Rotation around the the Y axis. Used when you want to lay a subwoofer on its side. A positive number rotates the sub clockwise from the subwoofers’ perspective.

Processing

The processing tab allows the user to set the gain, the delay of the subwoofer. The sub can also be assigned to one of 6 groups. See section on GROUPS ( page 5) for more information.

Model

The Model tab allows the user to select the model of subwoofer to be modeled. DDT3D includes 3 of the Danley subwoofers, the TH812, the DBH 218LC, and the TH118. In addition, we have included an idealized “true omni” subwoofer.

Crossover

The crossover tab can be used to set the low pass crossover for the subwoofer. The check box turns the crossover on and off. There a two ways that a crossover can be set for a sub. The Global crossover is adjusted under the Options tab. Use the Global crossover if all the crossovers in the system are likely to be identical. The settings of the Global crossover are shown greyed out if the Global crossover is chosen. The crossover can also be set to Local. The local crossover affects only the selected sub. Selecting the Local option activates the Frequency, Type and slope windows. The frequency can be set to any value from 20 to 500 Hz. DDT3D supports 3 types of Rilters, Bessel, Butterworth and Linkwitz-‐Riley, in 4 slopes 6, 12, 18 and 24 dB per octave.

Actions

The Actions tab allows the user to mirror any of the subs around either the y or x axis. When a sub is mirrored, an identical sub is placed on the screen as a mirror image of the original. It can be assigned to any unused number. A maximum of 20 subs can be used in DDT3D


DDT 3D Manual

DDT3D provides 15 presets of subwoofer conRigurations. Choosing a preset will create an array of subs at 0,0,0, and assign them to the Rirst unused group number. At the end of the list of presets is an option to reset all the subs to 0.

Speakers Tab

Selecting the Speakers tab will display 3 sub menus or tabs, with the Location tab showing. DDT3D allows the placement of up to 10 full-‐range speakers in the Sound Field window

The button with the number in it will turn the speaker red for easy identiRication

The check box turns the loudspeaker on or off. Off removes the image from the screen

This is a mute button , the image of the speaker stays on the screen, but the output is muted. Icon turns red when Mute is active.

Polarity toggle. Flips the polarity of the speaker. Icon turns red when polarity is Rlipped.


DDT 3D Manual

Location

The SPEAKERS/Location tab allows the user to place subwoofers anywhere in the 3D space using an X, Y and Z coordinate system. In the default view, X is left and right, with a positive value to the right. Y is front /back with a positive value towards the front, and Z is the up /down axis with a positive value being up. Under the OPTIONS tabs the user can select to show the coordinates axis in blue, black and red as shown below.

Danley SM60 at location 0,0,0 with X,Y,Z axis visible

Rotation Z -‐ setting rotation Z to 0 will point the speaker directly along the Y axis.

Inclination X -‐ Inclination is really rotation around the X axis. A negative number will tilt the speaker towards the Rloor.

Rotation Y -‐ Rotation around the the Y axis. Used when you want to lay a speaker on its side. A positive number rotates the speaker clockwise from the speakers’ perspective.


DDT 3D Manual

Processing

The processing tab allows the user to set the gain and the delay of the loudspeaker. The speaker can also be assigned to one of 6 groups. See section on GROUPS (Page 5) for more information.

Model

The Model tab allows the user to select the model of loudspeaker to be modeled. DDT3D includes all of the current full-‐range and mid-‐high boxes and 2 and 3 box arrays of those products which are array-‐able.

Laser Info

DDT3D allows the user to turn on a virtual laser which shows where a loudspeakers’ on axis point intersects with an audience. The laser can be activated under the OPTIONS tab. The point of intersection is shown under the Laser Info sub-‐tab. These aim data are also included in the Report.

A Danley SH60 at location 0,0 +20, rotation Z of +35, aimed at a Inclination of -‐22

The aim data for the above loudspeaker


DDT 3D Manual

Crossover

The crossover tab can be used to set the high pass crossover for the loudspeaker. The check box turns the crossover on and off. There a two ways that a crossover can be set for a speaker. The Global crossover is adjusted under the Options tab. Use the Global crossover if all the crossovers in the system are likely to be identical. The settings of the Global crossover are shown greyed out if the Global crossover is chosen. The crossover can also be set to Local. The local crossover affects only the selected speaker. Selecting the Local option activates the Frequency, Type and slope windows. The frequency can be set to any value from 20 to 500 Hz. DDT3D supports 3 types of Rilters, Bessel, Butterworth and Linkwitz-‐Riley, in 4 slopes 6, 12, 18 and 24 dB per octave.

Actions

The Actions tab allows the user to mirror any of the speakers around either the y or x axis. When a speaker is mirrored, an identical speaker is placed on the screen as a mirror image of the original. It can be assigned to any unused number. No more than 20 speakers can be used in DDT3D


DDT 3D Manual

Microphones Tab

DDT3D allows for up to 10 virtual microphones to be placed in the Sound Field window. Selecting the Microphone Tab brings up this window with the Location tab active.

The check box to the left of the colored box turns on a virtual microphone. As soon as a microphone is activated, a frequency response will appear in the frequency response window. The color of the trace corresponds with the colored box next to the check box. The microphone may be placed anywhere in the Rield using the X,Y,Z coordinate system. The default Z or height is 5.58 feet or 1.7 meters. You can also place a microphone on axis to an existing loudspeaker by using the tool on the right.


DDT 3D Manual

This tool will place anyone of the microphones automatically on axis with any active loudspeaker at what ever distance you choose.

In addition you can have DDT3D place a semi-‐circle of seven microphones around any active speaker or place it anywhere on the Rield. This is a very useful tool for examining the polar response of a speaker or cluster of speakers. It can be toggled on and off. If microphones are set out in the Rield the semi-‐circle command will temporarily override the existing mics. Turning off the semi-‐circle will re-‐activate the original microphones.

Shown here is a semi-‐circle of microphones placed around a SM 60 and the resulting seven response curves shown in the frequency response window.


DDT 3D Manual

The boxes on the right set the scale of the Frequency Response graph. The user can select 3, 6, or 10 db per division, and set the bottom of the graph i.e. “0” on the y axis to 80, 90 or 100 dBSPL.

If your mouse has a scroll wheel, place the mouse over the Frequency Response screen and click on the Y axis. The curser will turn to an up/down arrow and the user can select vertical resolutions other then the 3,6 and 10 dB. Moving the curser to the center of the Frequency Response window and the curser will return to the default crosshair. Moving the scroll wheel will now adjust the horizontal axis.

SPL

The SPL sub-‐tab will open a window which will display the sound pressure levels at each microphone utilizing, A and C weighting as well as the unweighted ( Rlat) sound pressure level.

Note, you can also see the SPL info displayed in a small box next to each active microphone but clicking on the A C or F buttons in the menu bar above the Sound Field window.


DDT 3D Manual

Audience Tab

In DDT 3D the audience is a very important tool as DDT3D will only map loudspeaker coverage on to an audience plane. It is certainly possible to build room out of audience planes as they can be any size and orientation. DDT3D comes with a selection of audience presets available in the Audience Presets pull down menu. All the presets are editable.

The X,Y,Z location boxes set the location of the origin of the default audience plane. You can then copy a audience plane and copy it to a new number.

This is the default audience plane located at 0,0,0

The properties tab lets you set the L( length) of the plane which is the distance along the Y axis, the Inclination, rotation and the width at the front and rear of the plane. For more on using Audience planes, see the tutorial.


DDT 3D Manual

Options Tab

The options tab is where a number of global parameters can be selected.

• The Rloor grid check box toggles the display of a Rloor grid. The pull down box lets you choose the size of the grid.

• The Show coordinates check box toggles the display of the red, black and green lines which show the orientation of the X, Y, Z coordinate system.

• The Show box numbers toggles the display of the number assigned to each active loudspeaker or subwoofer in the sound Rield window.

• The Inverse sound Rield colors check box toggles the sound Rield between black on white and white on black

• Set Defaults returns the program to the default settings

• Coordinates increment is a global way to set the increment steps in all the coordinates increment boxes

• The Prediction based on hearing planes check box sets the hight off the audience plane for the sound Rield prediction.

• The Global Crossover box is where the global crossover parameters are selected.

• By selecting this option and entering the temp and humidity DDT3D will accurately include the effect of air attenuation on the frequency response, per ISO 9613-‐1.


DDT 3D Manual

• The Minimum SPL ( Dark Blue) lets the user set the level at which the SPL display at the left of the 3d Rield screen turns Dark Blue, effectively setting the dynamic range of the display.

• The Distance/Delay Finder is a tool which will calculate the distance and delay between ay two active elements in the Sound Field window.

Projects Tab

The project tab has the tools for saving and opening DDT3D projects and adding notations to projects. Selecting the Projects Tab opens a window which allows the user to data pertaining to a DDT3D model. Selecting Export a Report creates and exports a pre-‐formatted report as a PDF document. The report includes all the data entered under the Projects Tab, as well as descriptions of each active loudspeaker and subwoofer, their locations in the X,Y,Z coordinate systems and their aim points.


DDT 3D Manual

Drawing Tab

The Draw tab gives access to a number of drawing tools which let the user create complex rooms in the Sound Field window. IMPORTANT! The lines drawn with the tools under the Draw tab, have no acoustic properties. The sound goes right through them. Only the Audience planes have acoustic properties. DDT3D allows for freehand drawing or drawing using the X,Y,Z coordinate method. See Tutorial #1 for a detailed demonstration on how to draw with the X,Y Z coordinate system.

2D Views Tab

The 2D Views tab lets you look at the 3D model from each of the 2 dimensional views, the top, side and front. At the bottom of each view window there are a pair of boxes labeled according to the view. The top view will have boxes labeled Y,X, the side view Y,Z and the front view X,Y. In each case the left hand pair of boxes shows the location of the mouse dynamically as you move the mouse over the window. When you click the mouse button at a location , the 2D coordinates are captured and shown in the pair of boxes on the right. You can then send those coordinates to any active loudspeaker or microphone or make that location the origin of the semi-‐circle of microphones.

Memory Tab

There are 3 memories which can store and retrieve coverage and response curves for easy comparison.

When you have a coverage map and a response you wish to save, click one of the 3 memory buttons above the sound Rield window. Then by selecting the Memory tab you will be able to compare the curves saved in memory.


DDT 3D Manual

TUTORIAL 1. A simple sound system

As a way to get familiar with the various parts of DDT3D, lets design and model a simple 2 way sound system in a small church. With DDT3D you don’t need to build a room unless you want to, but you must include at least one audience area, so lets start by building a few audience area which will represent the church. Click on the Audience Tab. We could select one of the presets and edit it to meet out needs, but for this tutorial, lets build an audience from scratch. Click the check box next to number 1. You will see that a small audience area appears in the Sound Field window. If you click on the Properties Tab you will see that the audience area has the dimensions of a Length of 5 feet and a Width 1 and Width 2 of 10feet. Go ahead and change the values for the Length and you will see that the audience grows along the Y axis. Changing the Width 1 parameter changes the X dimension in what could be thought of as the front of the space, and Width 2 changes the width of the rear of the room. In this way you can create trapezoidal seating areas. For example enter 50 in the L window, for a 50 foot deep seating area. Enter a value of 40 in Width1 and 60 in Width 2. You should see something like this….

Figure 1

Now experiment with the inclination. You will see that adding inclination adds “rake” to the seating area. This can be clearly seen if you select the 2d Views Tab and select Side view. You can clearly see the rear of the seating area is raised. If you Change the Z axis under the Location Tab, the entire seating are will rise to the value of Z. the Rotation Rield under Properties rotates the audience are about the Z axis, useful for building fan shaped seating areas.


DDT 3D Manual

So for our Church, lets start with a audience area of 40 ( L) and 50 ( width1) by 60 (Width2), with an inclination of 6. Then add audience 2. Lets set Audience 2 to the following parameters : Location, X=-‐42.00, Y=-‐8, Z= 0, Properties, L=40 Inclination 6, rotation -‐25 Width 1 = 10, width 2 = 51. You should see a new audience area to the stage left of the Rirst one.

It should look like this...

Figure 2

f you were watching your Screen as you were entering the numbers you would have seen exactly how DDT3D places audience areas on the screen. Now lets use the copy and paste feature to create a mirrored audience on the stage right side of the original audience area.

Under the Location Tab, select the copy button to the right of audience 2. Now select Paste to the right of Audience 3. You should see a new audience plane created but it is sitting on top of Audience 2. Simply change the Location X of Audience 3 to a + 42 instead of the -‐42, and you should see the 3 audience areas in their correct positions. In DDT 3D the Inclination is not copied and pasted. You will need to set the Inclination of audience # 3 to 6 like the others.

It should look like this

Figure 3


DDT 3D Manual

Ok, Here is a test ! Lets see if you can build 3 more audience areas so your plan looks like this:

FIgure 4

Here are the settings : Audience 4, Location 0,50,6 ( we need to raise the whole seating area to 6 because the Rirst tier is inclined) Properties, 20, 6, 0, 56, 63. Audience 5, Location -‐62, 33, 6 Properties, 22, 6,-‐25, 48, 56. Audience 6, Location 62, 33, 6 Properties, 22, 6, 25, 48, 56.

This would be a good time to use the 2D tool and check your Audience areas to make sure you did not forget something.

So now that you know how to create complex audience areas, lets simplify our lives a bit and turn off all audience except our original one, like in Figure 1.

Before we put a sound system in our simple church, lets build a simple model of the building. Remember that this model has no acoustical properties, but sometimes it is useful to see the audience are in context. (If you want to get right into building the sound system, skip ahead to Page 22)

So lets build a building around our audience area. Select the Drawing tab. The drawing system in DDT3d is actually very simple. You create vertices ( dots) then simply connect the dots with lines. Lets assume that our building is 80 feet wide, 70 feet deep, and the walls are 20 feet high, with a simple gable roof with the truss line running front to back, 40 feet above the ground. We are going to start by choosing the vertices for the Rloor. You can do it in any order as long as you wind up with all the vertices. Lets assume that the front wall of the building is 20 feet in front of the seating area ( Audience 1) That puts the Rirst vertex -‐ a sort of corner stone -‐ at X = -‐40, Y = -‐20 and Z = 0. You should see a red dot


DDT 3D Manual

appear at that location. Click New Vertex and set vertex 2 to the location X=40, Y =-‐20, Z=0. A new red dot appears.

Now create a new vertex # 3, at location X=40. Y=50 Z=0. THis sets the back corner of the room, which is 70 feet back from vertex 2. Complete the Rloor by creating Vertex 4 at X=-‐40, Y=50, Z=0. IF you wish you can now connect the dots. The simplest way is to use the Vertex 1 and @ boxes on the right had side of the screen. Set Vertex1 to ! and vertex 2 to 2. You should see a red line connecting point s 1 and 2 on the drawing. Click the “New Line Box and the red line turns black. Continue to connect the dots.

You should see this now.

Figure 5

If we create 4 more vertices we can create all four walls. Set vertex 5 at X=-‐40, Y=-‐20 and Z=20. This will set a vertex right above #1. Set Vertex 6 at X= 40, Y=-‐20, Z=20. Set Vertex 7 to X=40, Y=50, Z=20. And Rinally Vertex 8 to X=-‐40, Y= 50, Z=20. Before you connect the dots, lets create the gable roof vertices. Set Vertex 9 to X=0. Y =-‐20 and Z= 40. Set Vertex 10 to X=0, Y =40, Z=40. Nw you have all the vertices you need to create the “building”. You can choose to connect the dots any way you want. Mine looks like this.


DDT 3D Manual

Figure 6

This is a good time to check the 2D views to make sure it all makes sense.

Creating the Sound System

Now it is time to put a sound system in our church. The easiest way to place a speaker is to look at the Side View. Place your mouse over the spot where you think you could place a speaker which would cover the audience. Click your mouse ant those coordinates will appear in the right hand boxes. Send Coordinates to Speaker #1. You will see a speaker appear at that location. That will be the default SH 60. YOu can change the speaker to what ever you want. Remember the Rirst time you load a speaker into DDT3d it takes a few seconds to load. time. The next time you choose a speaker which has already been loaded from the library it will come up instantly.

Now go back to the Speaker tab. Using the Inclination control in the Location Tab, set the down angle until the “Laser” points to the center of the Audience area. Select the LoRe(s)button above the Sound Field Screen. You will see the coverage of the SH60 at 1 octave centered at 1K. You can experiment with different frequencies, and different resolutions of the map, but it is clear that a single 60 degree horn will not adequately cover the room. So lets try a SH 96. Select the SH 96 from the Model Tab. Now if you calculate the coverage it should look like this… I used the highest resolution to graph the coverage...


DDT 3D Manual

Figure 7

You will notice that the coverage map seem to be Rloating just above the audience plane. This is duet to the fact that DDT3d calculates the coverage at ear height. This can be reset or turned off under the Options Tab. turn of the “Prediction based on hearing Planes” and re map the coverage. It will now appear directly on the audience surface.

Lets now look at the frequency response of the system. Set a mike in front of the speaker. Again a simple way to do this is to look at the Side view in the 2D click where you want to place a mic then select “ send to Mic#1”. A mic will appear at the location you have chosen. The response curve will appear in the Frequency Response window.

Rigure 8

It might be a good idea before settling on this as a good design to check how much sound is hitting the back wall.

Remember in DDT3D the coverage is only mapped to an audience area. So lets make the back wall of our church an audience area.


DDT 3D Manual

Select the Audience Tab and click on the seventh audience check box. Why 7 you ask? If you have been following this tutorial, you will recall that we already used 2-‐6 in creating a larger fan shaped church seating area…. we will come back to that! So, Selecting 7 brings up a small audience box at 0,0,0. Move it to location 0,50,0. Now set the Properties/ Length to 20, Properties/Inclination to 90 and the Width 1 and 2 to 80. Now when you remap the same system you should see the amount of splash on the back wall.

I like quantifying the data by putting a microphone at the back wall to see the actual level hitting the wall.

So, with the SH 96 we can see the splash that hits the back wall, and we have the C weighted numbers to use for comparison. The sound hitting the center of the back wall is 3.8 db down froth aim point on the main audience area.


DDT 3D Manual

It might be useful to click on memory 1 to save this view in memory as we are going to try a different speaker and compare the difference.

Now lets try a different speaker, say a pair of SH 50. Select a pair of SH 50 from the Speakers / Model Tab. YOu will see that the frequency response and the numbers in the SPL boxes change instantly with out the need for re-‐mapping. You can see that there is almost a db less energy hitting the back wall with the 2 SH 50 speakers.

Ok so not a huge deal and this is not a tutorial in room acoustics or even systems design, but less energy hitting walls is a good thing!

Now before we end this tutorial, I want to make a point about reading model graphics. Lets put these 2 designs side by side.


DDT 3D Manual

At Rirst glance the one on the Left looks like it is painting the back wall lots more then the one on the right. Actually there is less then a dB difference as we saw. Because the one on the left is a higher SPL overall the splash looks worse. That is why it is always a good idea to see actual numbers as well as pretty colors when building a model.

Ok, before we leave this design, lets add a sub. Lets try a TH118 with the pair of SH50s. If we place it directly under the pair of SH50s, at location 0,-‐6.89,0 you should see a extended response appear in the frequency response window. Set the crossover for the sub and the SH50 to 100Hz. If you tweak the level of the sub ( I dropped it 6 dB) and add a bit of delay , you can get the response at the mikes to look pretty good.

Ok, so if you feel conRident now, turn on the other audience areas, edit the building to accommodate them and design a multi-‐element sound system!! Good Luck!


DDT 3D Manual

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