OPTIMIZING ORCHESTRAL SOUNDS
88 Starwood Rd. Nepean On, K2G 1Z5
The sound of an orchestra can vary considerable depending on the location in the hall. The configuration of some musicians for most orchestras results in their instruments being directed towards the conductor or the walls and not the audience. Hence, the full color of the sound for some instruments in the orchestra, such as the cellos, violas and the 2nd violins, is lost on the walls or ceiling of the stage. The sound of an orchestra could be improved by repositioning the members so that the sound from their instruments is always directed towards the audience. The direct sound from an instrument is louder and of a higher quality than that reflected from the walls, which is delayed, muddled, weaker and unbalanced. A wall can also absorb some of the frequencies and reflect others. Some first violins and brass are well positioned as their instruments are generally directed towards the centre of the hall and balconies. However, the 2nd violins need to be repositioned nearer to the conductor so their instruments face the audience. The violas might be in front of the conductor so that their instruments are more towards the audience. The cellos can then be positioned to the right side of the conductor. The double bass could move in closer on the right side of the cellos and the bass drum and timpani could be positioned beside the double bass to balance the orchestra or by the brass. Most of the members of the orchestra will now be on the left side of the stage so the conductor could be somewhat to the right of the stage for better visibility of all members (see sketch). However, this configuration is only a suggestion and others might be explored and tested.
A method to test the directivity of the various instruments of an orchestra is to measure it with some audio instruments. A simple way to accomplish this is to setup two directional microphones about a third of the way back from the stage and in the middle of each half of the hall. The sound from each microphone should go to a recording system with meters and to each side of some headphones. Calibrate the recording equipment with a single "omni" directional speaker in the centre of the stage so that the sound is the same level in both channels. It should also appear to come from the centre of the stage when wearing headphones.
Starting with the present configuration of the orchestra as a reference, have the group play a number of pieces with a variety of emphasis on different instruments and record the music. Then have each set of instruments play in turn, sustained low, middle and high notes so that the levels on the meters can be determined and recorded. Note the levels in both meters and play them back superimposed to note the differences. The signals could also be subtracted one from the other to see the differences in the signals. Then by trial and error have the members for each group shuffle about so that their instruments point towards the center of the opera hall and the sound level is approximately the same (within a few dB) in both meters. Generally the musicians on the right-hand side of their group should point their instruments to the right side of the hall. Similarly those on the left side should point their instruments to the left half of the hall to provide a more even distribution of the sound. Similar levels in both meters will result in well-blended high quality sound throughout the hall during a performance. Record the position of the members for each test. The sound should then appear to come from the centre of the stage when using the headphones. Repeat the process for the other groups. Merge the orchestra back together in a configuration that produces a balanced sound and is suitable for visual contact with the conductor if possible.
Note the bass and the cellos in the front will not be able to easily see the conductor so a camera, such as those in an iphone, might be set up to monitor the conductor. Then the video can be broadcast with a wireless router or sent via cable to the musicians in the front and displayed on an ipad or such device attached to the music stand. This should enable these musicians to readily follow the conductor and be in sync with the timing and any nuances that the conductor may have for the cellos and bass. Some of the violins on the far left hand side of the conductor may also need to have an ipad to monitor the action. Some compromise may still be necessary in order that the musicians can also see the conductor and their instruments can "see" the appropriate half of the audience.
Check the balance and directivity of the full orchestra by again playing sustained notes and with some music that has separate movements for each group of instruments. Compare the output (balance) with that of the original position of the members. Note music stands and chairs may have to be staggered and some of the piccolo, flute and horn players may need to be on risers or stand and have reflectors (oboe and clarinet) in order to clear obstructions. Document the tests and the results for later analysis and study. Rehearsals might also be recorded so that the blend and balance of the music can be checked. The new configuration should increase the sound level several dB and the sound will be direct, well blended, balanced and of high quality at most seats in the hall.
Pianos should always be placed such that the sounding board is fully exposed with the top at about 45 degrees and parallel to the front of the stage to reflect the sound towards the audience. The sound of a harp is limited so it should be near the front of the stage and could have a reflector to increase the level. Amplified sound should only be used as a last resort to increase the level of sound in a hall because such sound will muddle the original sound.
Some concert halls are very wide such as the Roy Tompson Hall in Toronto and the Southam Hall at the NAC in Ottawa. The directivity and clustering of some instruments results in an uneven distribution and hence unbalanced sound in such wide halls. A better distribution of the sound can be obtained by members of each group of the orchestra splitting into two clusters. Each cluster would play towards its closest half of the hall. This would provide a significantly improved balance and blend of sound throughout these wide halls.
Any comments, concerns or results of tests would be appreciated, thanks.