Everything You Need to Know About the Decca Tree Recording Technique

It’s impressive that we’re still talking about a sound setup that was created in the 1950s. The unbelievable longevity of the Decca tree recording technique is well deserved though. It’s simple, works with large musical arrangements, and offers a unique audio experience. 

It’s worth noting that after developing that technique, Decca Records won 31 Grammy awards, recorded hundreds of orchestral classical music concerts, full operas, and numerous film scores. 

The stellar roster of artists working with Decca at the time included Luciano Pavarotti, Herbert von Karajan, Ernest Ansermet, among many others. 

Here’s the story of one of Decca’s many experimental feats. The one that made recording these concerts possible. Maybe you can get some inspiration from it in your audio setups as well. 

What Is a Decca Tree? 

A Decca tree, in its simplest form, is an arrangement of three mics: two lateral, and one on the middle. It was designed especially for large musical assemblies like philharmonic concerts or Operas. 

Typically, the three mics are attached to a T-shaped boom, with the lateral mics spaced around 2 m apart. In the center, another mic is attached at a higher level and 1.5 m ahead of the twin mics. The central mic is often 3.2 m high, while the lateral ones hang at 2.5 m. 

Two more mics can be added at the periphery to capture more sounds. That is if the assembly or instruments are that sparse on the stage. The mics are typically placed at a significant height looming well above the music players and vocal performers. 

Traditionally, three Omni mics were used in the Decca Tree setup, particularly the Neumann M50. But later on, different brands like the Schoeps MK2S took their place.

A Bit of History

The Decca Tree arrangement is an experimental audio setup that was revolutionary when it was introduced. The stereo sound quality, mono compatibility, and stage reproduction were amazing. For the very first time performers were allowed to move around while singing. And the captured audio reflected that dynamic perfectly. 

Three British sound engineers stand behind the evolution of the Decca Tree: Roy Wallace, Arthur Haddy, and Kenneth Ernest Wilkinson. Their innovative and daring techniques were highly encouraged and rewarded. After all, devising new audio tech was part and parcel of what Decca Records stood for since its inception in 1929.

Similar Audio Setups

Some experts seem to think that the Decca tree setup is a variation of the ORTF stereo microphone system. It was devised at the Office de Radiodiffusion Télévision Française around the 1950s as well. 

There were a handful of microphone configurations at the time, with two main sound capture technologies: Omni and Cardioid. The ORTF system employed two Cardioid mics placed at a wide angle of 110 degrees. This allowed many guests to talk at the same time, without being committed to separate mics placed inches away from their mouths. 

For this system to work well, both mics had to be identical. The placement and matching of the mics might have inspired the sound engineers at Decca Records. But it could’ve been just a coincidence that the Decca Tree moved along the same lines. 

Where Does the Name ‘Decca Tree’ Come From? 

The Decca Tree configuration did resemble a tree, and that probably didn’t escape the observant eyes of the audio team. But it was Arthur Haddy who finally made a comment about it though, saying that it looked like a Christmas tree!  

The witty admission was clearly accepted by everyone, and they labeled their newest technical victory as the Decca Tree. 

What Is a Decca Tree Recording Technique Used For?  

Recording sound from a single performer, whether that’s a singer or TV presenter, isn’t too hard. You just place them in a sound room and use a good mic. 

Things get a little bit tricky when there’s a bunch of people, all talking at the same time. The difficulty level increases if the set is outdoors, crowded, and windy. Or, you need to record a musical concert live. 

The Decca Tree technique was invented for that last situation. There are tens of performers, distributed around a stage, and each one producing a unique type of music from various instruments. Only a well-distributed audio recording system can capture the gist of that event. 

It’s worth noting that some sound engineers use the Decca Tree setup for smaller assemblies, or even for solo players. It still gives stellar results.  

The Pros & Cons of Using a Decca Tree Setup

If you’re thinking about using the Decca Tree recording technique in your work, then it would be best to weigh in its limitations along with its strong points. 

The Strong Points 

Recording orchestral performances, operas, film scores, or even a medium-sized jazz band could be a real challenge. 

This seemingly simple arrangement of three mics on a T-shaped boom, actually, accomplishes quite a lot. The stereo quality is remarkable, but most of all, this method reproduces the various sounds on the stage. This includes movement, where each performer is standing, and where the music is coming from.    

The various tracks are then mixed in a way that retains all the uniqueness and freshness of the concert. 

The Limitations 

It’s hard to imagine that a hugely successful recording technique like the Decca Tree would have any downsides. However, nothing is perfect in our world! The issues here are by no means dealbreakers though, just a few points to consider. 

  • The mics that go into the Decca Tree configuration should be well matched to the point of being Siamese twins! Otherwise, they could create unwanted discrepancies. 
  • Typically, the mics used in this setup are seriously high-tech. Which often comes with a hefty price tag. You can practice with what you have, till you get better, and then buy better. 
  • The spacing, angles, and elevations of the mics are more of guidelines than strict measurements. This could cause some phasing problems if they are too close. 
  • A lot of experience goes into placing the Decca Tree mics the right way. And many sound engineers fail to get the required excellence out of this arrangement. This can only be remedied by experimentation and practice.  

In Conclusion 

Sir Edward Roberts Lewis, the founder of Decca Records, was a businessman and financier. He liked music, and couldn’t resist envisioning what a little investment could do in that field. 

In 1929, he took over a struggling company and put it on top of the music production arena for five decades. Decca Records survived some major historic events and managed to always come on top. 

The Decca Tree recording technique is one of many patented innovations accomplished in that company. And like the rest of them, a true game-changer. It’s an inspiration in more ways than one.