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Talking Theatre Sound Design with Peter McBoyle
Peter McBoyle is one of Canada ’ s most successful theatre sound designers and consultants . In his 20-plus years in the industry , McBoyle has designed the sound for countless theatre productions for the Stratford Festival , Charlottetown Festival , National Arts Centre in Ottawa , Troika Entertainment , Ross Petty Productions , Dallas Theatre Centre , and Twyla Tharp ’ s Broadway musical Come Fly Away , among others . He is also the owner of PM Audio Design and teaches theatre sound at Humber College in Toronto .
PS : You ’ ve said in the magazine before that on shows such as Stratford ’ s Sound of Music that you use a complicated delay matrix in order to image things to the stage , dividing the stage into zones and programming it so the delay times all shift to support the microphone in that zone . Can you explain why and when you use this delay matrix technique ?
Peter McBoyle : Time of arrival is one of the biggest issues that we deal with on musicals . When the cast and orchestra are contributing acoustic energy into the room , then the intelligibility and fidelity suffers if the time of arrival between the live and reinforced systems isn ’ t as close as possible . This “ source oriented ” reinforcement technique works on any stage configuration but is extremely helpful on thrust and in-the-round stages like the Festival and Tom Patterson theatres at the Stratford Festival . The challenge in these configurations is that the relationship between the actor and patron can be very different depending on where the actor is positioned . For example , if an actor is positioned on the extreme stage right side of the stage , then they are close to the audience on the stage right side and far from the audience on the stage left side . In a traditionally delayed system where the front fill speakers are delayed to the centre cluster , the signal from the performer ’ s RF mic would arrive late to the audience that is close to the performer and early to the audience that is far . So by creating areas on stage that have delay times set for the signals from the speakers to arrive at the correct time for the actor ’ s position on stage , you can attempt to get the time of arrival closer for all seats in the house .
We use SMAART or SIM to set eight to 10 different sets of delay times for all the speakers . We call this the “ delay matrix .” On the Digico SD10T we use at the Festival Theatre , we have a subgroup for each delay zone and the theatre software allows you to set a delay time for each matrix cross-point where the subgroup feeds to the output . In my experience this technique works very well when the reinforcement approach is subtler . It allows the audio system to be more “ transparent ” than without it because the level of the reinforcement is similar to the level of acoustic energy . As the show gets louder , then the sound system starts to overtake the acoustic level and so it becomes better in those situations to do a more common delay technique of delaying the system to itself so that the time of arrival for a fill speaker is in sync with the centre cluster or the main left and right , whichever is most appropriate .
PS : Can you explain how you design and implement these delay matrixes ?
PM : In Stratford , when I first started doing this , I used Meyer Sound ’ s Matrix3 digital matrix mixers to create this delay matrix . It worked but it was a bit cumbersome and it tied up a lot of
DSP to do it . Now we use the delay matrix that is a feature of the SD10T console . Either way , automation routes the RF mics to the correct delay zone cue by cue during the show , which we program based on the actors ’ blocking . There are even more sophisticated systems , such as TiMaxTracker from Outboard Electronics , which not only features an automated delay matrix but also features a wireless location system that tracks the location of the performer on stage and automatically moves the mic signal to the correct delay settings as the actor moves around the stage .
PS : Obviously intelligibility is a primary concern in theatre . During your 20-plus years doing this , which techniques or technologies have you discovered that have best-improved intelligibility on the shows you work on ?
PM : Certainly having a well-designed , welltuned , and highly cohesive sound system with the appropriate amount of power is the best place to start . Without that it will always be an uphill battle to overcome the deficiencies of the system .
After that I would say the next most important thing is a well-executed mix . Most people don ’ t realize how active the mix is on a musical . The mix engineer is constantly opening and closing mics and the goal is to only have the mics open when someone is speaking or singing . We don ’ t just open all the mics for everyone who is on stage and turn them off when they leave the stage as some people think . The interaction between mics would be terrible . With omnidirectional lavs on each performer ' s head you would get what I call the “ peanut butter cup effect .” Lots of one person ’ s chocolate in the other person ’ s peanut butter , except without the great taste . If two people are close to each other on stage , then their voices get in to each other ’ s mic at similar amplitude but at a different time of arrival . This creates comb filtering in the frequency domain and timing issues in the time domain . So you effectively take a good sounding signal , make it sound bad , and add echo or reverb to it by having multiple open mics . Even when cast members are further away it has a negative effect to have both their mics open . So we strive to get a tight mix and get any unneeded mics closed . This makes a huge difference to intelligibility and also , obviously , to gain before feedback .
56 PROFESSIONAL SOUND