RC-SIM

Hi, APFD friends.

The outstanding motor sound of APFD is based on the fact, that for each engine of an APFD aircraft there are 3 different sounds out of three rpm-ranges. These sounds are cross faded fluently, in case they are in a sufficient setup.

For a combustion engine the unbalanced chugging in idle, the “four stroking” under partial load and the full throttle sound can be simulated.

At multiengine aircrafts there are also the “beats” simulated.

This all depends on the correct settings in the .tmd-file. I have experimented a lot with this file and now I like to let you take part in my founding.

In this workshop I like to explain, like before in the weather-workshop, the settings in the .tmd-file.

Then I will show you, how you can rebuild the nice Saito-radial engine of the F7F –Tigercat that has been lost in the new AFPD version.

Unfortunately in a sound workshop it is very difficult to use any pictures. Therefore I recommend that you try all my explanation in parallel to reading this workshop.

This is the “control panel” in the .tmd-file that we will modify:

Sound0File = "db605-idle"
Sound1File = "db605-mid"
Sound2File = "db605-full"
Sound0RPM = 490
Sound1RPM = 1310
Sound2RPM = 1730
Sound01RPM = 600
Sound12RPM = 1600
SoundRange = 400


Now we will have a look into a .tmd file that is available on each system, it’s the .tmd from the
Spacewalker.

ATTENTION:
At first make a backup of this .tmd

Then open the original .tmd with the WordPad and look for the chapter “cd Engine”. You will find it near the lower end of the file.

Sound0File = "g15-3000"
Sound1File = "g15-5000"
Sound2File = "g15-10000"
Sound0RPM = 3008.2
Sound1RPM = 5270.4
Sound2RPM = 10202.7
Sound01RPM = 4000
Sound12RPM = 7000


In the first three lines we find the names of the use sounds. An according .wav-file for each sound must be available in the sound folder. Otherwise the aircraft will not have any sound at all.

Now have a look on the last two lines:
They control the crossover of the different sounds.

Sound01RPM = 4000
This means:
AT 4000 U/min the sound does cross-fade from Sound0 to Sound1.

Sound12RPM = 7000
This means:
AT 7000 U/min the sound does cross-fade from Sound1 to Sound2.

This can be heard clearly if you slowly increase throttle and have a look on the rpm.
(It can be seen best in a 3D scenery and F7 –view (follow).

The changeover is not hard but fluent.

If you change the numbers in the lines you can modify the rpm at which cross-fade will start.

Make some trials in the “Spacewalker” .tmd and don’t forget to save, otherwise you won’t hear any change.


Now we will have a look at the tone pitch settings:

Sound0File = "g15-3000"
Sound1File = "g15-5000"
Sound2File = "g15-10000"
Sound0RPM = 3008.2
Sound1RPM = 5270.4
Sound2RPM = 10202.7

The allocation is simple and logical:
“Sound0RPM” controls the speed of the output (and therefore the tone pitch) of Sound0File (g15-3000)

Sound1RPM controls Sound1File,
Sound2RPM controls Sound2File.

Now the most important: The HIGHER the number of Sound*RPM, the LOWER the engine sound!!

The tricky part is now to adjust the tone pitch of the sounds so, that during cross-fade the two sounds having the same tone pitches.


I hope that the participants of this workshop have already used their newly achieved knowledge to experiment a little.

Now we can also make the modification on the sound that is necessary because of the change of the AFPD-Sound System in the new version.

Example:
The F7F-Tigercat:
I was very proud of the sound of the  two radial engines. But after installation of AFPD 1.11.7.9 the sound was more like a turbine than a radial engine. The speed and the tone pitch were much too high.

With our knowledge this is not a problem anymore: We INCREASE the sound values to make the sound LOWER.

It looks like this:

Original values:
Sound0RPM = 600
Sound1RPM = 2600
Sound2RPM = 3800

Now we increase each part by the factor 2.5:
Sound0RPM = 1600
Sound1RPM = 5600
Sound2RPM = 8800


The Tigercat has the same sound than in the versions before 1.11.

If you like to try this, fly the Tigercat at first with the old values and then hear the big difference.

With the latest update another command has been added to the acoustic-block:

SoundRange = 400

With this command the range of the cross-fade between the sounds can be modified. The higher the number, the greater the range.

If you choose this number too small (below 100) you will get a gap between the sounds.

The SoundRange command can also be added manually, in case you have the latest AFPD version.

To make the settings it can be helpful to set SoundRange to “0”.

1. It is easy to hear the point where the fade is, if you slowly raise the throttle.

2. You can compare the two sounds directly. This makes it easy to hear if they have the same tone pitch.

When you are finished don’t forget to set SoundRange back to 100.




Sometime there is no need to have 3 sounds, because one is sufficient from idle to full throttle. An example is the Dutch military Piper-Cub. This aircraft sounds much better with only one sound.

What to do with the odd lines?

Sound0File = "piper_rpm1"
Sound1File = ""
Sound2File = ""
Sound0RPM = 2008.2
Sound1RPM = 5270.4
Sound2RPM = 5302.7
Sound01RPM = 6800
Sound12RPM = 7400


All lines below the first one (except of two) are odd and could be deleted.

Sound0RPM = 2008.2
This on is needed to set the tone pitch of Sound0File.

Sound01RPM = 6800
If you delete this the aircraft will not have any sound  (funnily enough) from half throttle upwards.

The trick is to set the rpm higher (here 6800) as the propeller will ever reach in real.
Therefore the first sound is sufficient for the whole rpm-range.

On the other 2 lines each value could be used, it wouldn’t affect the sound at all.

In the Download of RC-Sim there are some more models with one sound only (electric model do have only one anyway.)

I would recommend not deleting any lines at all. Just put a // before the line and the program will not take care of them.

In combustion helicopters the sound is to be set in the same way than in a combustion fixed wing.
But on a helicopter there is an additional sound that is displayed in parallel with all the others. It’s the blade flapping sound.

This sound is normally named “blade1” or “blade2” and can be found in chapter “cd Rotor”:

SoundFile = “blade1”

Here you MUST enter a valid sound, otherwise the heli will not have any sound at all.

For the blade sound the tone pitch can not be modified. It is dependent on the rotor rpm.

Also here a decline in version 1.11.7.9 can be claimed:
Up to this version the volume of the blade sound was also linked to the pitch (the more positive or negative pitch, the louder the flapping sound). This link has been deleted in the new version.


To be continued…….