Tracks properties

The main disadvantages of these polymers are (in addition to the poor tracking properties) ... 

We have mentioned several times already that clusters should allow one to bridge the gap between the atom and the solid, and to track properties from one to the other, so that phase changes and transitions of various kinds can in principle be mapped out experimentally. This constitutes an important application of cluster physics, and we now give a concrete example. 

Once it was recognized that degradation could occur in this manner it was necessary to have a test to allow the tracking properties of various materials to be examined. The test adopted was that due to Mathes and McGowan, now known as ASTM D2303. In this test a sample of material is mounted at 45 to the horizontal with two electrodes attached to its underside 50 mm apart. Contaminant (ammonium chloride and wetting agent) with a volume resistivity of 380 ohm cm flows at a controlled rate from the upper to the lower electrode. At the start of the test the... 

The Track Properties window displays all of the relevant information about the media file contents of a track. Since there are a few different kinds of tracks in ACID, the information displayed is dependent upon the type of track selected. Many of the properties that are displayed can be modified in this window (see Figure 1.20). While a media file (especially a loop file from Sonic Foundry) may already contain the extra information to specify a track s properties, these properties are independent of the actual file. In other words, a media file s ACID properties often correspond to a track s properties, but this is not necessary (an intended one-shot media file can be placed in a loop track). Video tracks do not have any properties that are displayed in this window. 

The Track Properties window displaying information about a loop track. 

A waveform is a visual representation of a sound file. Waveforms are visible in ACID in events, in the Chopper window, and in the Track Properties window, among other places. Ultimately, editing in ACID is done by ear, but you can make very precise cuts, splits, and trims simply by looking at the peaks and valleys of the waveform picture of a media file or event... 

Regions and markers added in the Chopper also show up in the Track Properties dialog (and vice versa). You can save regions (and markers) to the media file so that they can he accessed in other projects hy clicking the Save File button in the Track Properties window. 

So what makes an ACID loop an ACID Loop ACID loops are simply audio files available from Sonic Foundry that have had beat, pitch, and tempo information added to them. As mentioned previously, this information is useful only to ACID (and perhaps some other Sonic Foundry projects in the future). At this time, only loops from Sonic Foundry have this additional information, but this is not some carefully guarded secret. Anyone can create ACIDized loops. Information about a media file as it pertains to ACID can be found in the Explorer window and in the Track Properties window for files that have already been inserted into ACID, as shown in Figure 9.2. See the section later in this chapter about ACIDizing your own loops. 

ACID-related information about a media file (type, duration, tempo, sample rate, bit depth, channels, and compression) can be found in the Explorer window and in the Track Properties window for files that have already been inserted into ACID. 

The type of track into which an audio file is inserted can be changed in the Track Properties window. To view the Track Properties window, from the View menu, select Track Properties or press Alt + 6 on your keyboard. To see a specific track s properties, click that track the Track Properties window will immediately display that track s properties. The General tab in the Track Properties window has the Track type list, which displays and lets you change the type of track for that media file. 

Loop tracks and the media files that they contain that come from Sonic Foundry have beat, pitch, tempo, and type information saved with the file. Any audio files below about thirty seconds in length will be inserted as loops into loop tracks, with ACID s best guess about the beats and tempo. Pitch information will not be included, although pitch is an important aspect of Loop tracks. This is because Loop tracks can be pitch shifted automatically or manually. The Stretch tab in the Track Properties dialog is used to control this information. While most loop files contain pitch information, this is not really necessary for loops that are not primarily tonal in nature, such as drum and percussion parts. Most percussion loops are inserted as loops into Loop tracks and can have pitch information added, but they do not have a root note selected on the Stretch tab. 

Select the Save Beatmapper infomiation with file to add a small amount of data to the file and allow it to be used in other ACID projects. If this option is not selected, the media file will be Beatmapped only in the current project. The Save button in the Track Properties window does the same thing. 

Outside the Beatmapper Wizard, the Beatmapping of a media file as it is inserted into a track can be adjusted in the Track Properties window on the Stretch tab (see Figure 9.4). The first downbeat and measure adjustments can be adjusted while the main project is being played back to align the media in the Beatmapped track with the project. Use a simple drumbeat to compare the project tempo and beat with the Beatmapped track since there is no metronome associated with this window. 

The properties of a loop as it occurs in ACID are modified through the Track Properties window. To view a loop s properties once it has been inserted into a project (track), irom the View menu, select Track Properties. Click on a track to change the focus of the program to that track and view its properties in the Ttack Properties window. While a track s properties are initially determined by the information saved with the media file, the track properties are still independent and can be changed. The track properties always supercede the loop s properties. The specific properties that are available depend on the track type, as previously discussed. MIDI and video files can also be inserted into tracks, but not into audio tracks. MIDI and video tracks are dealt with in their own chapters. 

The Save button at the top of the Track Properties window saves any changes in a loop s properties to the media file on your computer. These properties are only informational in nature and do not change the characteristics of the media file. It is analogous to a caption on a picture. Press the Ctrl key on your keyboard while clicking the Save button to open the Save As dialog and create a new media file. 

The General tab in the Track Properties window serves a number of basic purposes It sets the Track type, displays the loop s properties, and allows you to add media file level markers and regions (see Figure 9.5). 

TuneUne—This is very similar to the timeline in the main program workspace. You can add markers and regions to a media file that will be saved with the file when you click the Save button at the top of the Track Properties window. See Chapter 3 for more information on using markers and regions in AQD. 

This tab is used to control stretching or compressing in time to accommodate a project s tempo. One-Shot tracks and files are primarily used for media that should never be altered in duration thus, the Track Properties window in this situation does not have this tab. There is a lot of information on this tab for Loop and Beatmapped tracks, however. 

The Root Note is the key of a loop. This property of a track can be changed on the Stretch tab in the Track Properties window of Loop and Beatmapped type tracks. The Root Note allows a track to be automatically pitch shifted to match a project or the key changes that occur in a project as a result of Key Change markers. Setting the Root Note to Don t Transpose prevents this from happening. Any time you want a loop to be protected from key changes, you should select Don t Transpose. You ll notice that most percussion and drum loops have Don t Transpose as a Root Note, as well as some vocal loops and, especially, spoken word loops. 

Insert it into a project and change the Track type to Beatmapped on the General tab in the Track Properties window. 

Test the looping of the event by duplicahng it (Ctrl+drag) and repeating it on the timeline. Listen to it and see if it works. Insert a simple drum part and see how it matches the beat. Go back to the Track Properties window and adjust the Downbeat and measure size. 

As long as the project tempo is the same as the tempo assigned to the media file, there is no loss of quality. It doesn t matter if you guess at the tempo in the Beatmapper Wizard or Track Properties window as long as the project and media files assigned tempo are the same, the file will not be stretched. 

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