Now that you have cut your teeth on basic Model Builder, let's look at some models that generate sound. We are going to look at a helicopter model and a jet model. These 2 models are not supposed to represent any particular type of aircraft, but are intended to show you how it's done. The control inputs needed to manipulate the models have been greatly simplified and may only be a subset of the controls sent over by your host computer. In short, use a big grain of salt when looking at these models.
These models can be found in the c:\mbuilder\demo\models directory, or below. The following files are for Model Builder 4.04 and above:
These models can be best heard on a system with a Waveform Synthesizer (WS) card by connecting a speaker to channels 1 and 2. It is possible to do aural with the RIUs, but the audio fidelity will not be very high and you will not get the separation associated with using 2 separate channels. If using an RIU, address it to 1 and connect the headset or AIU (if used) to Channel A.
If using a WS card, you will need 1300 credits and 2250 credits if using a TDM/RIU combination to run the helo model. When running the jet model, it costs 1600 credits with a WS and 2500 credits with a TDM card. The TDM/RIU combination requires more credits because the output channel cost is higher when using this type of DSP card. There is a distinct difference between the two types of hardware in that not all signal objects are charged when using a TDM card but they are all charged when using a WS card. For additional information, see Application Note #35 for a list of credits charged per object per DSP card type. If using packages instead of credits, you will need the "Engine" option enabled. If you do not have the engine option enabled, you can load these models but cannot save any changes you might make to the Engine Objects, and you will receive warning messages that the Engine Objects are for demonstration use only.
Both models are for 2 engine aircraft and, to give the impression of physical separation, the sound is directed out to 2 different channels of the WS. The left engine is heard primarily on Channel 1 with some sound going to Channel 2. The right engine is primarily heard on Channel 2 with some sound going to Channel 1. On the helo model, the rotor and airflow noises go to both channels in equal amounts. On the jet model, the airflow and afterburner noises go to both channels in equal amounts. If using an RIU, you will not get the same impression of separation because you will only be listening to one output channel. Confused yet? Don't worry, it will make sense once we actually start to make some sounds.
Get into the c:\mbuilder\demo\models directory and type:
mb helo
This loads the helo demo model (helotut.mdl) onto DSP1. If you have a 2 DSP system and the first card is a TDM and the second is a WS, then edit the "helo.cfg" file as follows:
Change model1=helotut.mdl to model2=helotut.mdl. Save these changes then type:
mb helo
and the model will be loaded onto the WS instead of the TDM.
NOTE: If you only have a TDM card in your system, you will have to reduce the model sampling rate from 16 KHz to 8 KHz. This parameter is found on the Model Configuration Window. Highlight the value, press "Enter", type in the number "8000.00" and press "Enter".
Make sure your speakers are connected. Channel 1 on the left, and Channel 2 on the right. Separate the speakers by about 2-3 feet if you can.
Go into the "Controls" list. The objects that we will be dealing with are right at the top of the page. They are; Master_Volume, Helo_left_th, Helo_right_th, Collective and Helo_Airspeed.
If you don't remember how to get to the Controls List, here is a quick reminder. When Model Builder starts you are put in the Main Model Directory and the "Models" field should already be highlighted. If not, use the arrow keys to move up to this field or press the "m" key. You are now in a submenu, highlight the model number corresponding to the WS and press ENTER. If you only have 1 DSP in the system, just press ENTER when "model1" is highlighted. You are now on the Model(x) Configuration Window, where x is the model number you chose. You should see "HELOTUT.MDL" in the "Filename" field. If not, you are on the wrong model. To get to the Controls list, press F2, highlight "Controls" and press ENTER. You are now at the top of the Controls List.
The Master_Volume parameter is already at a mid-range value, the other controls are all zeroes. To change this value, highlight the Master_Volume object, press ENTER and use the arrow keys to move down to "Test mode". Use the "+" to toggle it from OFF to ON. Then change the "Input" parameter with the "+" and "-" keys to ramp the value up or down. Use the ESC key to exit from this object.
From the Controls List highlight the "Helo_left_th" and press ENTER. Highlight the "Test mode" field and change it from OFF to ON with the "+" key. Highlight the 0 next to "Input" field, press ENTER and the number will change from blue to red. Use the number keys to enter a value of "10" then press ENTER. The number 10 now appears in blue and you should hear some low noise on the left channel. Use the "+" key to slowly ramp this value up to between 85 and 100. You can enter numeric values directly instead of using the "+" and "-" keys. Use the ESC key to exit from this object.
Highlight the "Helo_right_th" object and press ENTER. Using the steps described above, turn on this object's "Test mode" and ramp up the Input value until it matches the left engine throttle setting. As the right engine spools up, you will hear some thumping as the rotor begins to spin faster and starts to beat against the air. If this is not accurate for your type of helicopter, don't worry. This is just a demo and your real model can be manipulated to sound however you like. Once you have ramped up the right engine, use the ESC key to get back to the Controls List.
If it is starting to get noisy, turn down your speakers or change the "Master_Volume" control as described above. To kill the sound altogether, press "F3" to put the system in a freeze state. Press F3 again to release the freeze state and the sound will resume.
Highlight the "Collective" control and press ENTER. Move down to "Test mode" and change it from OFF to ON. Change the "Input" from 0 to 10 and use the "+" key to ramp up this value and simulate pulling pitch with both engine inputs at 95. Generally, the collective sounds best when you move it through the range of 50 to 95. Use the ESC key to get out of this object and back onto the Controls List.
Highlight the "Helo_Airspeed" control and press ENTER. Move down to "Test mode" and change it from OFF to ON. Change the "Input" from 0 to 20 and use the "+" key to ramp this value up. You can start to hear a rushing noise around a value of 50 and it peaks out at 100.
Now realize this is purely subjective, but we think this model sounds pretty decent with a volume of 5, left and right throttle settings of 95, collective setting of about 85 and airspeed around 90.
Get into the c:\mbuilder\demo\models directory and type:
mb jet
This loads the jet demo model (jettut.mdl) onto DSP1. If you have a 2 DSP system and the first card is a TDM and the second is a WS then edit the "jet.cfg" file as follows:
Change model1=jettut.mdl to model2=jettut.mdl. Save these changes then type:
mb jet
and the model will be loaded onto the WS instead of the TDM.
NOTE: If you only have a TDM card in your system you will have to reduce the model sampling rate from 16 KHz to 8 KHz. This parameter is found on the Model Configuration Window. Highlight the value, press "Enter", type in the number "8000.00" and press ENTER.
Make sure your speakers are connected. Channel 1 on the left and Channel 2 on the right. Separate the speakers by about 2-3 feet if you can.
Go into the "Controls" list. If you do not remember how to do this read 3.1.2, "Quick Refresher", in the Helo section above. The objects that we will be dealing with are right at the top of the page. They are; Master_Volume, Jet_left_th, Jet_right_th, Jet_Airspeed and Afterburner.
The Master_Volume parameter is already at a mid-range value, the other controls are all zeroes. To change this value, highlight the Master_Volume object, press ENTER and use the arrow keys to move down to "Test mode". Use the "+" to toggle it from OFF to ON. Then change the "Input" parameter with the "+" and "-" keys to ramp the value up or down. Use the ESC key to exit from this object.
From the Controls List highlight the "Jet_left_th" and press ENTER. Highlight the "Test mode" field and change it from OFF to ON with the "+" key. Highlight the 0 next to "Input" field, press ENTER and the number will change from blue to red. Use the number keys to enter a value of "10" then press ENTER. The number 10 now appears in blue and you should hear some low noise on the left channel. Use the "+" key to slowly ramp this value up to between 90 and 100. You can enter numeric values directly instead of using the "+" and "-" keys. Use the ESC key to exit from this object.
Highlight the "Jet_right_th" object and press ENTER. Using the steps described above turn on this object's "Test mode" and ramp up the Input value until it matches the left engine throttle setting. If these engine sounds are not accurate for your type of jet, don't worry. This is just a demo, and your real model can be manipulated to sound however you like. Once you have ramped up the right engine, use the ESC key to get back to the Controls List.
If it is starting to get noisy, turn down your speakers or change the "Master_Volume" control as described above. To kill the sound altogether, press F3 to put the system in a freeze state. Press F3 again to release the freeze state and the sound will resume.
Highlight the "Jet_Airspeed" control and press ENTER. Move down to "Test mode" and change it from OFF to ON. Change the "Input" from 0 to 20 and use the "+" key to ramp this value up. You can start to hear a rushing noise around a value of 50 and has a max at 100. At higher values, the air noise starts to drown out the engines. Once you have added airflow noise, press ESC to quit and go back to the Controls List.
This is a simple afterburner noise that goes from OFF to full afterburner. We know it is not wholly realistic, because afterburners have segments but we did not model them here. To turn it on, highlight the "Afterburner" control, press ENTER, turn ON the "Test mode" and change the "Input" value to ON. You will hear a roaring noise that is quite a bit louder than the engines. We realize that you can turn this afterburner on at any time, even if the throttles are below 100%, but we did it this way in order to make it easy.