The acoustical quality of University broadcast and recording facilities can make or break the studio, and student experience. It’s best to plan ahead, before you go on air.
Campus TV and Radio stations can be a landmark on a college or university campus. Students often stand in front of the studio port windows, intentionally made for eager onlookers, to gaze at a live production and listen to the broadcast.
While these types of spaces in action may be mesmerizing, they are also challenging spaces to design acoustically, and require much forethought and good planning. In particular, radio and TV studios require a low background noise level, low reverberation time, an even distribution of sound, and a high level of sound isolation. Getting all of those criteria in a single space is clearly where the engineering work, done by independent acoustical consultants, comes in.
Low background noise levels are a product of unit sound level, proximity, and airflow rate. How loud is the HVAC system that feeds the studio, and how close is this unit to the studio? Additionally, is it a designated unit that can handle the heat-load of a studio, with performance lighting and sometimes several bodies in a relatively small space?
Maintaining airflow that travels smoothly though the ductwork and exits diffusors at a low velocity can be a challenge, and often requires upsizing of ductwork. To decrease the sound pressure level produced by the fan of an air handling unit, duct silencers and/or extra duct length with internal duct lining may be necessary. While individual units and treatments can be added later, it’s much more cost effective to take those steps during the construction process, rather than wait for the inevitable complaints.
When looking at the room acoustics of a studio, reverberation time and diffusion are two key elements. Reverberation time can be thought of as how long a sound sustains within a space. For TV and Radio Studios you typically want a short reverberation time. These “dry” environments accurately and clearly capture the people’s voices that are being recorded or broadcast. To achieve the correct conditions, the reverberation time of the space should be analyzed across a wide spectrum of frequencies. This includes incorporating various acoustically absorptive materials designed to absorb sound at different frequencies such as a bass trap to help control low frequency sound.
The shape of the room itself is another factor. Small rooms will often interact with the wavelength of sound at different frequencies. Flat reflective parallel surfaces could result in flutter echo. Ideally, dimensions that lessen the impact of sound reflection should be used in production studios. Diffusive material can be incorporated to help scatter sound evenly within the room. As with any acoustical treatment, designing them into the space in the first place can create a pleasing aesthetic, as well as the greatest level of effectiveness.
Sound isolation is the last, but not least, step in planning a studio. There’s nothing more frustrating that having a perfect take, only to find that the squeak or rumble of a cart being wheeled down an adjacent hallway was picked up by the microphone. To achieve the right level of isolation for a studio environment, details are essential. Wall types, floor and ceiling design, doors, seals, and control room windows are all potential weak links. In sound isolation the weakest link is always the limiting factor of a system, so eliminating as many points of sound travel as possible will help your studio be a success.
A campus TV and Radio Studio is a complex acoustical environment, filled with challenges. If acoustics are not taken into account early on in the project, these can quickly become budget-busters. Hiring an independent acoustical consultant, like ABD Engineering & Design, early in the project, can provide you with the engineered solutions before starting construction. Starting sooner helps you work acoustics into the initial design, to achieve the best results.
- Western Michigan University – WMUK Radio
- Hope College – Martha Miller Center