Drums are the most difficult instrument I've tried to record. In reality, I am still rather horrible at the traditional method. This is a result of many problems including lack of knowledge, bad room, bad mics, bad isolation, etc... I am a guitar player, not an engineer (well actually I am, but the wrong type!) so I try and find the easiest, quickest, and least expensive ways to get good sounds. I would much rather focus on creating. For the drums, I realized quickly that I would not have the room to properly record drums and gaining the skill to properly EQ, FX, and mix drums was not something I had much interest in.
Solution: Triggering. yea yea... triggering is for cheaters. Well, go complain about it elsewhere. Music is music. It's the final result that matters. So long as there's a human still playing a real instrument and it's set up properly the feel of a real live human being will come through.
There are several issues to overcome when triggering a drumset:
1. Triggering Hardware (analog-MIDI conversion)
2. Latency
3. Samples and Layering
I'll discuss (mostly) the recording element to recording drums, covering each of the above topics. More detail in the "triggering hardware" category will be provided in another post, which will discuss our eDrum setup.
1. Triggering Hardware:
Triggering a drumset requires a few components: a drumset (well not really, just something to 'hit' that has the desired feel/response like a real set), trigger sensors (typically piezos), and an interface to interpret the analog sensor signals. The interface will apply some conditioning, digitally convert the signal, apply processing in the digital domain, then export the MIDI data.
The hardware is most important to retaining the response of a real set. You want the sensors to pick up the lightest desirable hit to the hardest 'crack.' This is a little more difficult than it may sound. We've spent a great deal of time trying many sensor configurations (additional post to come...) and it is important that you start with the sensor. You know the motto: garbage in, garbage out! Using a scope, we (BTW, we = drummer and I) were able to test each sensor configuration across the span of hits over the range of the amplification section of the eDrum's input modules. This is important to 'view' as you can quickly map the 'hit curve' (as we call it).
Latency:
When recording a real live drummer with triggers it is important the drummer be able to hear the resulting 'hits' along with the rest of the tracks. Any instrument has this feedback. Without it, the player cannot adjust. High latencies can cause serious problems or even disallow the player to play the instrument. Latencies should be dropped below 5ms to allow 'live' playback and recording. You can perform several tricks to drop latency - check out the forums of your particular DAW to see recommendations. Tips will include such things as buffer resizing, dropping running apps, and other OS-related tweaks. Some PC hardware configurations will not allow certain latencies without dropouts or other major functionality issues - if this is the case and you need those latencies, a computer upgrade may be due. If the drummer doesn't need to 'play along' with any other track, then absolute miminum latency really isn't an issue, provided the hits do not occur too fast for the aquisition and the drummer can still hear him/herself while playing. However, it is indeed much nicer to have the actual samples used for the mix fed back to the player in real-time.
Samples and Layering:
So now that we have MIDI data that corresponds to some real-live event, how do we make it output realistic sounds?! 2 major contributors: Sample set quality and decent layering/mapping tools (the drummer's skill doesn't hurt either!).
The audio samples are the actual audio components that play during each MIDI event. It is obvious that the quality of these samples directly defines the quality and realism of the drum track. I am using the Steven Slate Drums set (check em out - they're grrreat as Frosted Flakes). It includes high-quality .wav files for many different drums, each 'mixed' in a different way (including raw and room mic'd samples) and at many different hit strengths. Having a wide range of hit strengths in the sample set is far superior to simply increasing/decreasing the volume of a single sample since any percussive instrument makes vastly different sounds at different hit velocities (don't believe me - record (with any mic, doesn't matter) the snare... hit it light, then hit it hard. Normalize the volumes in your DAW and now you will believe).
This is where a decent mapping software becomes essential. There are several out there including: Drumagog, Hydrogen (if your using GNU/Linux or don't want to pay yet still have a decent mapper), Battery, etc... I am using Battery for my projects. I find it the easiest to use and it works seamlessly with Sonar (even in 64b Vista!). I used Hydrogen when I was running Ardour in Linux, but Ardour's MIDI editor is still not finished (meaning you have to use external: Rosegarden) and although it was awesome for the money :), Sonar still allows me to spend less time fiddling getting things sounding the way I want.
Creating a drum map consists of a layering procedure where the lighter hit samples are linked to lower MIDI velocities and harder hits linked to the higher MIDI velocities. Battery also allows crossfading between samples in the layer, which makes the hit range even more seamless. For snares, I usually place the 'rolls' at the lowest MIDI velocities and then go from soft to 'crack.' For most metal/hard rock work, the hits will be hard-crack regions. Having the soft/med. ranges allows ghost notes to come through nicely.
Battery 3's layering and crossfading:
Applying effects to the drum track in the DAW is quite minimal since I use the samples that are pre-mixed by professionals. All I really have to worry about are levels making my life 'recording' drums a dream!
- Phil
