“There are many applications which, architecturally, necessitate a blended approach of both surface and ceiling loudspeakers to provide sound reinforcement to the listener,” explained Travis Nie, loudspeaker product manager at QSC, as he gave CI an close-up look at the new series. “Spaces such as shopping malls, restaurants, retail, hospitality, and even conference rooms often utilize both types of loudspeakers simultaneously.”
However, these two different types of loudspeakers are a little bit different in their tones, which can result in a disjoined experience for listeners when moving from one room to another.
While most loudspeakers consist of a two-way design with a woofer and a separate tweeter, a typical ceiling loudspeaker will utilize a coaxial design with the tweeter radiating in free space on a post centered in front of the woofer, according to Nie. “The tonal characteristics of loading or unloading a tweeter are quite different and nearly impossible to match using equalization.”
DMT to the Rescue
QSC incorporates a design philosophy called Directivity Matched Transition (DMT), Nie explained. DMT matches the high-frequency waveguide to the natural conical behavior of the woofer at the crossover point.
“The result is a smooth transition between woofer and tweeter for even coverage both on and off axis,” said Nie. “This design philosophy is implemented across all QSC loudspeaker platforms, including our new AcousticDesign ceiling loudspeaker series which utilizes a carefully crafted DMT waveguide. By using the same design philosophy on both surface and ceiling models, we can create products that share a tonal resemblance.”
DMT allows QSC’s team to achieve remarkably consistent timbre and tonal characteristics between both surface and ceiling mounted systems.
“Let’s take for example the AD-S4T, a small format 4-inch, two-way surface mount loudspeaker,” said Nie. “At the 2kHz crossover point, the woofer is behaving 120 degrees conically. The high-frequency waveguide is then matched to create a 120 degrees conical DMT system. Our new AD-C4T ceiling loudspeaker—also a small format 4-inch, two-way system—utilizes the same principles to create the same 120 degrees conical DMT system.”
The new AcousticDesign ceiling series by QSC will be available June 2016.