December 18, 2020
Recording an orchestra is a complex task. It requires a close consideration of the venue’s acoustics as well as the size, composition, and placement of the ensemble. By addressing these factors effectively, producers and sound engineers can ensure that an orchestra’s sound is reliably reproduced, communicating both the force and delicacy of its varied instruments. Here are our top pieces of advice on how to record an orchestra.
Consider the venue
The acoustics of a space are always important for sound recording, but they become even more so with an orchestra. A large ensemble requires a large space, and the shape of that space determines how sound travels around it and how it’s recorded.
When it comes to capturing the sound of an orchestra, engineers generally agree that a ‘shoebox’-shaped concert hall creates the best acoustics. This is because the walls reflect sound waves to areas of the space where ‘directional hearing sensitivity’ is most acute. In other words, listeners or microphones receive sound waves from different directions, creating the impression of immersion. A shoe-box shaped space also affects the perceived dynamic range of the orchestra’s sound, amplifying fortissimo passages whilst maintaining pianissimo ones.
Aside from the shape of a venue, the materials contained within it also affect the quality of sound recorded. Both concert halls and recording studios contain mostly hard, smooth surfaces which reflect sound waves. Soft or rough surfaces, on the other hand, absorb sound and create a ‘muffling’ effect.
To help achieve a balanced mix in the recording, instrument sections are placed according to volume and impact. Louder instruments such as brass and percussion are positioned at the back, whilst strings and woodwind are brought towards the front. To avoid any clashing or uncomfortable sounds, instruments with similar range are positioned opposite each other, on either the left or the right of the sound stage. This applies to live and studio recordings.
Orchestra microphone techniques
One of the most common microphone setups for both live and studio orchestral recordings is the Decca Tree. The Decca Tree is a T shaped bar that holds three mics, keeping them stable and facing different elements of the orchestra. This can help alter the depth of some sections later on when mixing.
The size of the ‘Tree’ can also be adjusted depending on the size of the ensemble. Generally the mics are hoisted about eight to ten feet above the conductor, although this can change depending on the acoustics of the room. The mics on the left and right are often pointing slightly inwards and down, with a central mic pointing directly forward. The central mic is flanked by two microphones on either side, spaced at an equal distance apart.
The advantage of the Decca Tree setup is that it allows microphones to be almost ‘within’ the orchestra, whilst allowing engineers to capture different areas of the ensemble with minimal setup. The most commonly used microphones on a Decca Tree is Nuemann’s M 50 , an omnidirectional mic.
Close-miking is a technique used in most recording setups, and can be particularly useful when trying to record an ensemble with multiple sections. To put it simply, close-miking is when a microphone is placed close to the sound source, often no further than 12 inches away. The main reason for this is to
isolate ambient noise and sound waves from other instruments, and avoid distortions. Close-miking is used to gain the highest sound pressure level of the targeted instrument and lowest sound pressure level of any surrounding noises. Using this method helps control various sound pressure levels, ultimately helping to create a cleaner mix later on.
Orchestras can be difficult to mix because of the variety and amount of instruments involved. To achieve a good orchestral mix, delicate and precise EQ tweaks are often required. When it comes to orchestral music, EQs are often used to add higher frequencies to sounds and to help control the mid range which can naturally be too intense.
Capturing a concert hall
By assessing a venue’s acoustics and materials, and pairing correct section positioning with microphone placement, it’s possible to reliably record the sound of an orchestra. With our tips and advice, we hope you’re able to capture the essence of your orchestral music.
If you’re looking to record your orchestra, get in touch with Kore Studios. Our award-winning producers have worked with artists across multiple genres, and are on hand to offer their expertise on recording, mixing, and mastering orchestral music.