New Videos Address Real-World Amplifier Specifications

Two news videos provide a tutorial on the power output capabilities of the new DPA/DPA-Q amplifier platform, and using real-world program material as a means for designing systems.
12/29/2014

In a new video recently released by QSC Cinema, Barry Ferrell, the company’s Senior Vice President and Chief Strategy Officer, provides a tutorial and demonstration of the power output capabilities of the new DPA/DPA-Q amplifier platform.

“With the advent of immersive audio and the need for high powered surround loudspeakers, we’ve seen a fair amount of ‘overspecification’, where amplifiers are sized larger than they need to be for most common cinema applications,” says Ferrell.  “Part of this comes from a misunderstanding of amplifier performance and specifications.”  The video provides an overview of QSC’s new Class D amplifier platform, which is used in the DPA/DPA-Q cinema amplifiers and the CXD/CXD-Q and PLD series professional audio amplifiers.  Because of the platform’s extremely DC high voltage rails and regulated power supply, the amplifiers are able to produce much higher peak power output compared to conventional linear amplifiers, which translates to increased dynamic headroom without clipping.  The burst power specifications are representative of what the amplifiers will provide with real program material (such as a cinema soundtrack) as opposed to a sine wave test signal.  “These are the numbers we should be designing with, when calculating amplifier size for a cinema installation,” says Ferrell.

The intent of the video is to help cinema dealers and customers more accurately specify power amplifiers for cinema sound systems in order to avoid needlessly throwing away “unused” amplifier watts into a system.   Properly specifying power amplifiers saves money that can be used to invest in other improvements to the system–whether it’s better loudspeakers or more loudspeakers, or acoustical improvements to the room.

The power specifications video can be viewed here.

Amplifier AC Current Requirements

Another new instructional video discusses the real-world current draw requirements for power amplifiers.  Barry Ferrell demonstrates the actual current draw using sine wave, pink noise, and real program material as the input source.

“We get a lot of questions about ‘How big does the circuit breaker need to be? How much current do I need to supply?’ when designing equipment racks and determining electrical requirements,” Ferrell notes.  “Sine wave ratings of power amplifiers can lead to the assumption that large amounts of current are required, when in fact, that’s not necessarily the case. The reality is that with the dynamic range of program material, the current draw is actually fairly low under most circumstances, and short term peaks can be readily tolerated by most circuit breakers.”

The current draw requirements video can be viewed here.