KB219: Sound Project Files-Creating and Editing

This article was last updated on Sept. 3, 2012, 6:50 p.m. | Print Article | Leave Feedback

With Digitrax Sound Definition Language, you can use .wav files to create custom sound project files. The process of converting 'raw' sounds recorded in the field into a sound project file takes time and patience to produce a finished sound project file that sounds realistic.

Tips for Recording Locomotives and other Sounds

Recording the sounds is a major part of creating great sound projects.  You need good recordings to work with.
 

  • Record several complete sound events (several complete whistle blows from start to finish, etc.). This will give you several recordings to choose from when editing to produce your sound project.
  • If possible, make these recordings each time varying distance from the Locomotive. A single recorded whistle blow may sound great by the siding, but may not sound as good once you listen to the recording at home; get several recordings from different distances and give yourself the latitude to choose the best.  It's easy for the very loud sound of a locomotive to be too much for your recording device resulting in less than wonderful recordings.
  • Making several recordings will also help you avoid picking up unwanted background noise on all of the recordings. Things like a car driving by or a bird chirping are NOT sounds that come out of real locomotives. If you make several recordings of each sound you are more likely to be able to find sound fragments that don't have these extras.
  • Once you've chosen the best recording, you'll need to isolate the complete sound by trimming the excess time from the recording.
  • The goal is to get just the complete sound event (whistle/horn blow/etc) with almost no sound before or afterwards on the recording. Once you've got it, save this file. Save a copy of it (with a different name) in a safe place on your hard drive.


Digitrax defines two kinds of sounds: simple sounds and sequenced sounds.

Simple Sounds

A simple sound is a sound that always sounds the same and always has the same length.

An example of a simple sound is a bell. The striker strikes the bell and it rings for a certain length of time.

To prepare a simple sound, using any sound editor software (there are several links to free sound editors on the Sound Depot web page):
 

  • Isolate the sound by trimming the excess time from the recording by carefully marking the beginning and the end of the sound you want to hear.
  • Save this trimmed file as a .wav file as an "8 bit" and 11 KHz file. Note the file name and where it is saved.
  • Open & Run the SoundLoader software.
  • The main screen of SoundLoader shows various parts of the locomotive's sound scheme (Diesel Bell, Diesel Brakes, etc.).
  • Locate the sound type you want to change in this list and "right-click" on that entry - click on "Assign Sound File."
  • Browse to the .wav file you've created, select the file and click 'Open.' This will insert the new .wav file into the sound project file.
  • Use the File|Save command to save your customized sound project file (.spj) with a new file name.


Repeat these steps and replace as many (or all) of the sound types as desired in the original sound project file.

Once you've created this new sound project file you can download it directly to your sound decoder installed in a locomotive using SoundLoader's "Program" button.  We encourage you to share your new .spj with your friends and to upload the sound project file to the Digitrax Sound Depot website for other users to enjoy.

Sequenced Sounds


A sequenced sound is a sound that is made up of three parts: an Attack sound, a Sustain sound, and a Decay sound.

  • Attack is the starting sound
  • Sustain is the running part of the sound
  • Decay is the 'end' sound


One example of a sequenced sound is a horn. Blowing the horn for 15 seconds requires:

  1. Attack sound that begins the sequence.  It is the Start part of the sequence.
  2. Sustain sound that prolongs the sound. It is the Run part of the sequence.
  3. Decay sound that completes the sequence.  It is the End part of the sequence.


In actual practice, file sizes for the beginning and end of the sound, the Attack and Decay, may possibly be larger than the Sustain because the Sustain is simply a small snippet of sound repeated as long as needed.

Other examples of SoundFX sequenced sounds are the Whistle & Water Pump.

In the SoundLoader main screen you'll see each of these sounds have a Start, Run, and End component.

To prepare a sequenced sound you'll need to make 3 different .wav files One for the Attack, one for the Sustain and one for the Decay.

The Attack or Start Part

Listen to your recorded sounds. You'll probably want to do this several times to find the best recording for each part. Your patience will be rewarded.

Depending on the sound editor you're using, playing from the beginning you'll eventually be able to mark a place on the timeline where the sound stabilizes. In other words, you'll be able to hear the point on the timeline where the tone of the sound starts to remain constant.

That's the point where you want to make your first cut.

Save this file segment as a .wav file in the 8 bit / 11 KHz format. Be descriptive with your file names, if it's a horn recording name it something easy for others to identify like: GMF7_horn_start.wav

The Sustain or Run Part


This one is straightforward; depending on how long the total recording is most of it will be the stable run part of the sound.

Cut out a one second or less piece of this sound and save it.  Use the sound editor software to listen to this sound running as a continuous loop to make sure that the looping transition sounds realistic. If you do not like what you hear, go back to your original recording and take another piece of the sound.

Remember to, name it something consistent and descriptive like: GMF7_horn_sustain.wav

The Decay or End Part


Mark the point in your recording just before the run sound starts to change, copy from this point to the very end of your sound clip.

Save it naming it something like: GMF7_horn_end.wav

Building the Sound Project (.spj file)

Once you have your three .wav files, you can either insert them into an existing sound project file or create a new .spj using the software.

  • Open & Run the SoundLoader software.

Use the File|Save command to save your customized sound project file (.spj) with a new file name.

  • The main screen of SoundLoader shows various parts of the locomotive's sound scheme (Diesel Bell, Diesel Brakes, etc.).
  • Locate the sound type you want to change in this list and "right-click" on that entry - click on "Assign Sound File."
  • Browse to the .wav file you've created, select the file and click 'Open.' This will insert the new .wav file into the sound project file.
  • Use the File|Save command to save your customized sound project file (.spj) with a new file name.



With these instructions and a lot of patience on your part, you can customize any sound project file or create your own new ones, there's no limit to what you can create with Digitrax SoundFX!

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