Ok. Checked it out, kind of glad you brought it up Merc. Acidized loops work the best in my opinion. I've had Acid Pro for a minute now and never knew it did this. I'll be making loops and converting all my other loops before I use them this way from now on!
HERE'S HOW U DO IT:
Creating ACIDized WAV files
First, you need a PC, or a Mac Dual Core running Windows. Get ACID - there are free and trial versions available here:
http://www.acidplanet.com/tools/?p=acid&T=2414
Open up a new session in ACID, then open the loop you'd like to convert into the program. In the "Track Properties" window, select the "Stretch" tab. You will see the waveform with the markers. The markers can be moved by adjusting the "transient detection" amount, or by hand. I like to test the marker placements in loops by previewing them at 15 - 20% less than their original BPM. Incorrect marker placements will create a "flam" sort of sound at this lower BPM.
Also, check to make sure the number of beats is correct. Adjust the Root Note if the loop contains a chordal center.
Save the ACID loop information by hitting the SAVE button in the Track Properties window.
A few tips:
- With larger wave forms, such as bass or synth sounds, consider putting in less markers - say quarter notes instead of sixteenths. This will help prevent the "warble" sound when tempo gets shifted.
- Make sure you have "don't transpose when stretching" selected to ensure the pitch doesn't change when a user varies the tempo.
- In the "Track Type" window, for the most part, you will want to select "LOOP" instead of "one shot" or "beatmapped." This allows the loop to have the most flexibility when the tempo or key is being changed from its original.
- Try the ACIDized file at a 10-20% lower BPM. Listen for warbles and flams and adjust transients accordingly.
- Transpose the ACIDized file (if they have a key set) up to verify that transposition is working.