Figure 6- Monitor your progress
This stops the preview from playing. By Previewing, we have adjusted the filter and confirmed that it is doing its job. The next step is to click on the Run Filter button. This takes the filter just as you have set it and applies it to the demo1 file and creates a new file in the lower window. This new file has been run through the filter and has the clicks removed. At this point, click on Close in the Impulse filter window since we’re now done with it.
Look at the two waveforms. The top one is called the Source. This is where we normally work on a file, preview filters, etc. The bottom is called the Destination and is the result of our filtering efforts. You can play either one by clicking in the respective window. You have not changed your original file at all – rather we’ve created a new cleaned up version.
Now it’s time to remove that rumble sound, but how can we do that if we work on the Source window and we really want to remove the rumble from the semi-clean file in the Destination window? The answer is a little command under the File menu called Make Destination the Source. This moves the file in the bottom window up to the top where we can work on it. Click on File/Make Destination the Source now.
A File Selector box will come up and suggest a new name for this file; just click on Save to accept it. Note: MILLENNIUM will automatically assign sequential names to new files. While you’re new to the program, always just accept its recommendation as to file names.
Now we are ready to remove that low frequency rumble. To do that, we’ll choose the High Pass filter. Click on Filter/High Pass now. A high pass filter will remove all frequencies below a certain point and
allow all higher frequencies to pass. file de-rumble”. It’ll look like this:
Figure 7- The Highpass filter
We’ll start to go a bit quicker now since you already know what most of the buttons and controls do on this filter. To find out specific info on this filter, don’t forget you can call for help clicking on the Help menu item. We are going to free you now to preview and play with this filter on your own, but when you’re done, return it to these settings by once again clicking on the demo Wave file preset. Run the filter when you are ready. Note: There’s quite a lot of low frequency rumble in this file, but if you have cheap computer speakers, you may not be able to hear it. Trust us, it’s there.