The Macintosh uses special information within its operating system to keep track of the types of files it can access. Sound Forge software can save the audio data in the correct file format, but it can’t tell the Macintosh what type it is.

To do this, you must use a program on the Macintosh (such as ResEdit) to change the file’s type. You simply need to set the Type field to AIFF for the Macintosh to recognize the file as a sound file. There is also a third-party utility called AIF Typer that is available for download from our Web site.

Sound Forge software has built-in support for the Microsoft Audio Compression Manager (ACM). This allows you to open files that are compressed with a variety of algorithms including Microsoft ADPCM, IMA ADPCM, and other third-party compression schemes such as the DSP Group’s TrueSpeech.

If you can’t open a Microsoft ADPCM file, you may not have the Microsoft ADPCM driver installed and enabled for the ACM.

Not all software for converting .wav files to Redbook audio handles the file structure correctly. Some software simply skips the first 44 bytes of data in the file and then considers everything else in the file to be audio data. This means that if you have saved Summary Information, Sampler Information, or Regions and Playlist data in the .wav file, it will be interpreted as audio data.

If you are experiencing this problem, simply use the Save As command in Sound Forge to save a new .wav file with the Save metadata with file check box cleared.

You can open an existing RBK file as the file raw file type in Sound Forge’s Open dialog box. Remember that you will have to swap the channels if you want to maintain the correct left/right channel settings.

RBK files are simply raw PCM sound data files. These files are used by some compact disc recorders to store Redbook audio onto a compact disc. RBK files are data only and contain no other information. They are stored as 16-bit, stereo data with a sample rate of 44,100 Hz. There are a number of things that make them different than a normal 16-bit raw file:

• The channels are stored in reverse order.

• The data is stored in Big Endian format (Motorola).

• The data length of the file has to be a multiple of 2,352 bytes (1 CD sector). The size of a CD sector is calculated as follows:

1 second of 44.1k, 16 bit, stereo audio = 176,400 bytes

CD audio has 75 sectors of data for each 1 second of audio

Sector size = 176,400/75 = 2,352 bytes

When saving files as Macintosh AIFF and transferring them to my Macintosh, why doesn’t the Macintosh recognize them as sound files?

Why won’t Sound Forge open my compressed files like Microsoft ADPCM?

After converting .wav files to Redbook audio using the software that came with my compact disc recorder, there are audible clicks at the end of the track.

My compact disc recorder uses a file type with an .rbk extension. What is an .rbk file and can I open it with Sound Forge?