Recording Brass and Woodwinds at Home
By Ken Hamberg
The brass and woodwind families enjoy a unique and pervasive presence as both ensemble and solo instruments in a plethora of musical arrangements for the orchestra, the marching band, and the popular song. In this article we’ll look at the manner in which these instruments produce their sound and how to best record them in the home and project studios or in location recording environments.The Brass Family
The members of the brass family include the trumpet, the cornet, the flugelhorn, the trombone, the tuba, the euphonium and the French horn. Their design, which consists of a series of tubes opening like a flower into a bell, hasn’t changed much since the mid-19th century. Sound is produced by blowing air with pursed lips into a mouthpiece at the start of the tube and depressing various keys to produce notes. The sonic character of these instruments mainly originates from the vibrations of the bell.
Brass instruments are notably loud and exhibit a very wide dynamic range, particularly in their lower registers. As a family their frequency range is from 29Hz (bass and contrabass tubas) to over 10kHz (trombone). Brass instruments can also produce very intense sound pressure levels at the bell – a trumpet, for example, blowing a high note at a distance of 1.5' will blast about 130dB of SPL. The same instrument playing in the same register from 14' away is still producing over 96dB of SPL.
The point is that brass instruments in general sound better when miked at distances from 2-6' or more, with the mic aimed roughly 30-40° off-axis from the center of and positioned a few inches above or below the bell. You’ll avoid high-SPL mic distortion, wind-pop and boom as well as overemphasized directional harmonics, which are usually harsh and strident in character. This mic technique is best applied to recording trumpets, trombones, and their various cousins. Tubas and French horns sound best when miked above and a bit behind the shoulder, again off-axis from the bell. This approach essentially shields the mic from much of the mechanical noise produced by the keys, and adapts well to the fact that these instruments are usually played in a seated position.
Brass instruments (and woodwinds as well) sound good in larger, livelier, and minimally damped reverberant spaces with harder reflective surfaces such as wood or concrete. Hallways and bathrooms often work well too, as tile and bare wall reflections can be very attractive and create the illusion of a greater apparent space than actually exists. You may want to have the player face the wall or tiled surface with his or her back toward the mic and try to catch those reflections. In a controlled and sound-treated environment, try taping an omnidirectional boundary mic (again off-axis from the bell) to a wall or large glass window surface. It’s an old studio trick that often involves the control room glass, and it works.
When recording brass ensembles, a pair of omnidirectional overhead mics 8-9' in the air and 1-5' apart, positioned at a distance of anywhere from 8-15' generally works well. The musicians will usually work out the dynamic balance and tonal blend amongst themselves. When recording trumpet or trombone players that are using a mute, it’s generally a good idea to reposition the mic roughly 2-4' closer to the source. Mutes will raise the instruments’ pitch and require more force (one dynamic level louder than written) to project the same level.
Woodwinds instruments include the clarinet, oboe, bassoon, saxophone (think brass clarinet with a larger bell) and flute (silver or silver-plated). With the exception of the flute, woodwind mouthpieces include a reed; clarinets and saxophones use a larger, wider single reed, oboes and bassoons deploy a slimmer, narrower double reed setup. By blowing across the reed(s) a vibration is created which stimulates a sympathetically-vibrating column of air throughout the tube-like body. The length of the tube is covered by a series of keys covering specifically-spaced holes that determine the acoustic length of the tube in terms of pitch. The tube ends in the form of a small bell, whose vibration, along with the sound emanating from the keyholes, contributes to the sonic signature of the instrument.
Unlike the brass family, most of the woodwinds’ sound comes from the body of the instrument (the keys and the mouthpiece) as opposed to the bell. They possess a very wide dynamic range and a frequency response rich in harmonic content that extends up to 12kHz. Both the clarinet and the saxophone project very strong high frequency content from the bell which reflects back from the floor to blend with the low and mid frequencies emanating from the body. Woodwinds are not as loud as their brassy brethren, projecting a maximum 95dB of SPL at 6.5' (the saxophone). Woodwinds in general, and the saxophone and oboe in particular sound best in lively, reflective spaces, so unless your recording space of choice is exceptionally and unattractively boomy minimal sound damping is advisable.
Since so much of the woodwind sound comes from the body of the instrument, the microphone should generally be aimed toward the lower middle part of the body at the players’ left hand. This necessitates more awareness on the part of the engineer of the mechanical noise produced by the keys, depending on the experience and technical expertise of the player. The predominance of odd over even harmonics in the lower registers of the reed instruments contributes to their characteristically nasal, hollow or “woody” sound.
A somewhat more distant miking approach works best with woodwind instruments, although close miking is often applied in pop or big band recording contexts where they might be overpowered by the volume of brass and electric instruments. For recording a clarinet or saxophone the mic may be positioned 3-7' away from the instrument, in front of it and roughly level with the top half of the body aimed at the keyholes in the lower half. For the saxophone some will move the mic to a distance of 1-3', positioned in front of and above the instrument aimed toward the middle of the body at the left hand. This will help to blend the low and mid body frequencies with the high harmonic content produced by the bell. A cardioid pickup pattern works best for this approach.
As a secondary or even primary microphone, a PZM boundary mic in omni mode taped to a hard reflective surface such as a wall or window will often work wonders for the saxophone, creating a nice sonic expanse while rounding off some of the “honking” character that instrument sometimes projects. When recording the flute, an overhead approach with a cardioid mic 6-12" (pop) and 3-8' (classical) away, aimed on-axis midway between the mouthpiece and the center of the instrument should yield a nice blend of breathy character and body tone. Again, listen for distracting mechanical and exaggerated breath noises.
As with any other instrument, don’t be afraid to move the mic around to achieve the best results. It’s also worth noting that unlike many guitar and bass players, you’ll rarely find a completely self-taught trumpet or saxophone player, or one that can’t read music. They’ll often be the most experienced and professional (not to mention expensive) players at the session, and often, due to the physical demands of performing a brass or woodwind instrument, the most easily fatigued. Be aware of this if your production technique involves layering two or three different solo instruments, a common studio “fattening” technique for brass in particular.What Mic Should I Use?
Large-diaphragm condenser mics, ribbon microphones, and the aforementioned PZM boundary microphones are all very capable choices for recording brass and woodwind instruments. The large-diaphragm condensers often sound best in omni mode; properly positioned they deliver an open, natural sound and adeptly capture the occasionally transcendent blend of room and instrument.
Some large-diaphragm dynamic mics in cardioid mode will also work very well, particularly for trombone, trumpet and sax at distances of 2-4'. Ribbon microphones, which come in both dynamic and condenser flavors, are typically configured in a figure-of-8 polar pattern. They can be very effective when recording both solo and ensemble brass or woodwind instruments in larger ambient spaces, capturing the instruments in nice detail along with the reflected sound from walls and windows.
The PZM boundaries work beautifully in omni mode as either primary or ambient microphones, often rounding out the more strident upper-register edges of an instrument while preserving its inherent flavor and character.
We should mention that the 2-4kHz presence peak exhibited by many large-diaphragm “vocal” condensers will often accentuate the “honk” of a tenor or alto saxophone playing in that frequency range. The fundamental range of the flute peaks between 2-3kHz as well. If you don’t have access to another microphone, those frequencies may be cut using console or DAW equalization to counterbalance the mics’ reproduction.
Brass and woodwind instruments can work very well in electronic musical contexts as well. A tuba doubling a synth bass line and properly mixed can create a powerful and very different texture, and a creatively-filtered tenor sax, trumpet, flute or trombone solo
We trust that we’ve demystified the design and the process of recording the brass and woodwind instrument families, and we hope that you’ll be able to expand your personal palette of sounds for your arrangements and recordings. These instrumental textures will breathe fresh life into a stale track every time.
Below you'll find a selection of useful gear for recording brass and woodwind instruments.Sound Treatment Microphone Stands Microphones Pop Filters/Windscreens
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