Refurbishment for the BBC's beautiful Art Deco Radio Theatre.

While comedy classics like Just a Minute (first broadcast in 1968!) stubbornly refuse to transfer across to TV, we the viewing public have much to thank the BBC Radio Theatre for, not least The News Quiz which spawned Have I got News for You on BBC 1. Following extensive refurbishment the Radio Theatre has become more than a venue for the comedy breeding ground that is the six-thirty evening slot on Radio 4. A national treasure in more ways than one, its classic 1930's Art Deco interior has also become a burgeoning 'must play' venue for pop concerts broadcast live on Radio 2. The fact that U2 chose this hallowed theatre to launch their latest album in the midst of a media blitz, says much about its reputation; Mark Diamond, Events Manager BBC Audio & Music explained just how far reaching that reputation is.

"The design is pure Art Deco with a capacity of around three hundred. In its lifetime the theatre has undergone several refurbishments, the latest began two years ago." This included a significant audio upgrade courtesy of Orbital Sound's Sales department. "It's a large double height room; the reverb has been reduced substantially from the original 1930's concert hall design to very dry, but not totally." The dilemma here for PA sound is live versus broadcast, how does a theatre sustain intelligibility and audiences listening pleasure while satisfying the needs of the transmission. "As with all acoustical issues, it's a combination of things, what we have at the theatre is really a large studio environment in a theatre setting. For the comedy shows how we record laughter track is to place multiple microphones directly above an audience with loudspeakers interspersed between them." Though shows such as The News Quiz and Just a Minute are always recorded 'as live' (with a live audience present at the time of recording), it's not unusual for the audience for a TV show to be presented with an empty stage and the playback video of the show to enable recording of audience laughter separately. "The loudspeakers we've installed have a very tight response, and with assistance from d&b audiotechnik we have been able to plot the nulls very accurately and positioned the mics there and thus reduce colouration from the loudspeakers to a minimum."

Orbital installed the distributed system of E0s. "The loudspeakers provide a subtle boost to the listening area," said Orbital's Tom Byrne who oversaw the installation. "By definition there will always be some colouration", added Diamond. "But this is very low in comparison to the levels we obtain from the audience, and the nature of the sound off axis is pleasant, full bandwidth, rather than peaky. That makes it acceptable."

Diamond cited an apposite example. "When we do 'as live' to broadcast, as in the case of say Just a Minute, then we're broadcasting from the audience mics, and from the panellist microphones simultaneously. It is recorded ahead of time, but the audience is live in the room with the panellist so it maintains the live ethos. From that comes the challenge of audience level, the panellist may be soft spoken so levels from the overhead PA must be powerful enough to convey not just the words, but the subtly of the humour, so they need to hear as clearly as possible. The conundrum is for the Broadcast Balancer who has the audience send-to fader; if the audience track becomes too loud he can always reduce the PA level to them, or he can reduce their captured sound to balance to the panellist mics." It's a delicate finesse, but one that has seen the Radio Theatre welcome an ever increasing demand for its facility in this specialist field.

Yet it's not just this subtle audience system that received attention from Orbital, "The main theatre PA system refurbishment sought to address another pressing problem" said Byrne. "Leakage of sound, particularly bass, into adjacent broadcast studios. With design support from d&b's John Taylor we resolved an installation of Q-Series comprising flown Q1s with Q-SUBs rigged in cardioid mode. The pattern control this configuration brought to the low-end propagation minimised leakage, with the added benefit of eliminating backward spill onto the stage area."

Beyond the now solved leakage problem the new system has also brought an unexpected benefit. "When we stage concerts here the PA levels are much higher, but tolerance of PA sound into audience mics is a lot higher of course" explained Diamond. "In fact it's desirable in that instance as that is where the live’ ness of the broadcast originates. And of course the audience tends to make most noise between tracks. With the theatre's previous incarnation we didn't really have a serious PA system and that presented problems in terms of time. Now we're ready quicker, clear up faster, and owning our own system has proved remarkably efficient."

Diamond's department at the Radio Theatre has a third, flexible response system, for impromptu events. "We already had a portable system of d&b Q7 loudspeakers powered by D6 amplifiers for use as a high output system in remote locations", said Diamond. "But we wanted a smaller lighter system for the many press and conference events that take place throughout the facility. Tom at Orbital demonstrated the new d&b E-Series to me; a very different cabinet construction from our other loudspeakers, but entirely consistent in terms of performance. Lightweight and portable; the E8s and E12s we've added to our inventory make for an excellent mobile system."