As it turns out, I've spent the whole day enhancing drum tracks for my band's album project. I only have three drum tracks to work with: kick (mono), snare (mono), and stereo toms/OHs. My goal is to layer kick and snare samples along with the original tracks, not full replacement.
Once you change the little dropdown menu from "Clips" to "Audio Transients" you'll see the markers. In my experience, most will be pretty good, but dozens per song will be so early that you'll hear a flam (Sample followed by audio clip).
My solution is to painstakingly go through every drum hit on the track (zoom WAY in) and verify that the transient marker is exactly at the start of the beat. It's tedious work, but the end result is worth it.
I also find that light hits on the snare drum aren't getting marked, but if I lower the threshold, it triggers on bleed from the high hat and first rack tom. So I also have to make sure every light hit is triggered as well (right click on the diamond and de-select "Disable").
Once I am happy that all my transient markers for a track are correct, I click on the clip, and press the A key to show the AudioSnap window. I display the Properties to let me choose which MIDI note I want to create (usually C3 for kick, D3 for snare). I also set the velocity vary with the volume.
Next I create an empty MIDI track to hold the data. Then back to the AudioSnap window to click the Copy to MIDI button, press shift-G to line up the insert point, create a MIDI track to insert the data to, then ctrl-V to paste the MIDI data into the track.
Finally create an audio track, insert your drum soft synth of choice, and connect the MIDI track to it. Personally, I'm liking the "Classic Rock" kit in Session Drummer for kick and the SI "Hall Kit" snare for snare. Blend the sample with the audio to taste.
We recorded to a click, but you can still feel the drummers tempo vary a little or have a slightly off hit. I haven't tried fixing those (yet), but snipping the bad hit into its own clip and moving it a tiny bit has worked in the past. The trick is to hope that you don't notice any glitches in the overheads from the bleed.
Oh, in response to your question, here is how you turn Audio Transients on:
post edited by garry - 2013/12/21 16:15:20