Recording Wind Instruments
Recording the Wind section.
Having covered the picking up of trumpet, trombone, and saxophone last month, I'd like to mention two woodwind instruments you may come across in your recording activities: the flute and the clarinet. Then I have listed a few hints on how you can help wind players improve their intonation, a sensitive point especially with amateur musicians. I feel that the contribution brass or reed players can make to certain pieces of music is extremely valuable; the way a horn is played connects it tightly with the musician and it lets you feel a lot of the musician's soul and musical taste. So it may be well worth the extra effort. After that we've included a paragraph on miking up harmonica.
This has a frequency range between 150Hz and 12kHz, the high end consisting of overtones and breath noises that appear when the instrument is played loudly and aggressively as opposed to the slick, cultivated style one knows eg. from Benny Goodman's recordings.
The clarinet radiates sound from the bell as well as from the fingerholes. To get a mix of both of them, try different mic positions; Figure 1 should work fine.
Keep in mind that the sound from the bell will head for the ground and the floor's reflection characteristics will therefore also determine the sound (carpet is mellow to muddy, wooden floor is neutral). Use a good mic with flat frequency response (condenser).
The flute's frequency range is from 250 Hz to about 8kHz. Its radiation characteristics are interesting: coming from the mouthpiece and the first open hole, the sound is projected to the front as well as, above 3kHz, to the side. You may employ a second mic to capture that sound as shown in Figure 2. The main mic is prone to pick up unpleasant wind noises, if the flute player gets too close. Also, he or she should blow below the mic, since the air stream is directed downwards and will be away from the mic this way. Working distance from the mic should be 4 inches minimum.
Again a condenser mic is a good choice (Neumann types, AKG C451). Vocal mics are fine because of their built-in windshield. Alternatively, a small condenser mic (Countryman, AKG C567 or the like; may be attached to the flute with tape (Figure 3). Rotating the microphone enables you to control the breath noise.
When recording horns or reeds you can't expect as steady a performance as from guitars or keyboards. Intonation, especially of players lacking experience may differ from one take to the next and it's sometimes difficult for the producer to decide when to repeat a passage. I don't want to go into any lengths about arrangement, safe ranges for instruments etc., but I'd like to pass on a few hints I picked up through the years, how you - the engineer, producer - can help the musicians.
Instruments, as well as players, have to warm up before tuning. The variation of the speed of sound with temperature is the physical reason for pitch changes in wind instruments when taken from a cold place to a warmer place or vice versa. Cold instruments are too low in pitch.
On the other hand, high notes on brass instruments, especially sustained ones, diminish substantially the strength of the muscles in and around the lips. Tired brass players tend to play flat, also losing clarity of the tone. So, when recording don't let them play more than what is absolutely necessary.
If you have enough tracks at your disposal, let the horns play their part twice on two different tracks. You can use this for doubling (a good sound), and keep the 90% perfect take, while going for the ultimate one - and in case it won't be, there's still something on tape.
A good trick is to reduce tape speed, especially for rock/funk riffs. Technical difficulties are reduced, there's more space to breath in tight arrangements and high notes will be somewhat lowered. A minor third (about 10%) lower is just enough to prevent a 'Mickey Mouse' type sound.
When changing tape speed, have a reference tone recorded in front of the take for tuning purposes (don't use the Dolby test tone, though, but some Bb or A note or whatever). And don't let your horn players be ashamed, because you need to use that gimmick: Earth, Wind and Fire do it all the time!
When overdubbing, plan ahead what to do first. Never let a horn player do a doubling an octave lower or a bass line as an afterthought. Record low or bass lines before or together with the other parts of the arrangement. Also unison passages with strongly vibrating sounds (strings) are difficult to do as an overdub.
Some trumpet players tend to be a little sharp when playing a lead or a solo part. It makes the horn sound brighter and it's okay, but don't let him (her) overdo it, and don't add any instruments in unison later.
I have come across producers and arrangers checking proper intonation outside the control room. They go into an adjacent room, leaving the door slightly open. Probably, it's easier to check whether a tone has exactly the right pitch if you're out of the monitors' direct radiation path.
The harmonica has a surprisingly wide frequency range from about 70 - 150Hz (depending on its size) to over 20kHz. For the typical blues harp sound you wouldn't want these high overtones. Harp players get the typical sound by playing close into a dynamic vocal mic eg. Shure SM58, AKG D330, EV PL80) (Figure 4). You can get an even dirtier blues touch by hooking the mic up to a guitar amp and picking up the signal from the speaker with another microphone (this will boost the mid range).
Alternatively, pick up from some distance, maybe with a condenser which will make for a more neutral sound.