August 20, 2008
PSB founder explains to CEPro Magazine, the priorities behind PSB’s loudspeaker design.
07.29.2008 — Paul Barton, the chief designer and founder of PSB, formed his opinions over the years working with the famed Canadian National Research Council.
In this Q&A, he explains his perspective on what loudspeakers sound best — and why.
Q: How does freestanding loudspeaker design differ from that of architectural products?
All of our loudspeakers are developed with the use of an anechoic chamber.
The difference between freestanding product and architectural product is in the way the measurements are interpreted.
A freestanding product propagates into the listening room in 4pi [full spherical radiation] and an architectural product radiates in 2pi (half spherical radiation).
Therefore, we must keep that in mind when voicing the crossover so the sonic signature of the two different speaker types sound as accurate as possible.
The major challenge with architectural product is to design and install the systems so that they do not mechanically vibrate the surrounding structure.
The major challenge with freestanding products is for us to voice the crossovers and box tuning to best integrate with typical room set-ups. The question is: What is a typical room set-up?
Q: In your opinion, what is the most overlooked aspect of speaker design?
I think good designing is the ability to understand what the priorities are. For PSB, they are, in order of importance:
- Frequency response.
- Off-axis dispersion as it relates to early reflections and sound power (the total energy radiated all around the speaker).
- Bandwidth (the span between the lowest to high frequencies).
- Dynamic range.
- Non-linear distortions.
The one that is most misunderstood is “off-axis dispersion,” which is very important and contributes to what we hear in a room.
We not only hear what is coming directly from the speaker, but we also, over short periods of time, integrate the direct and reflected sounds as one acoustical event. Therefore, the direct and early reflections define the timbre of the sound we hear.
Getting this right takes many measurements as well as many time-consuming, controlled listening sessions.
Q: If you were to write the curriculum for PSB’s speaker training programs, what parts would you emphasize?
As the custom installation industry has matured over its relatively short history, I’m still surprised and disappointed that not many installers understand how to do good measurements and calibrations of their final installations.
There are may PC-based systems that are easy [to use] and affordable. With some effort on the installers’ part, they would add value and generate more revenue because the systems would really sound demonstrably better.