Dynamic Balance®

Dynamic Balance

Laser Interferometry Lab at
the Johns Hopkins University

Dynamic Balance®, a major breakthrough by Polk, resulted from a laser interferometry research project done in partnership with the Johns Hopkins University. This full field laser imaging research enabled us to view the entire vibrating surface of a driver or tweeter. In this way we could see the resonance which develops on speaker cones as they move. The resonance is the root cause of frequency response distortions.

Just as an x-ray enables a physician to discover the root cause of a symptom and effect the right treatment for a cure, laser imaging allowed Polk engineers to find the right combinations of materials, geometry and construction techniques to tune out the offending resonance. We call this technology Dynamic Balance.

Dynamic Balance technology produces flat frequency response, sharp detail, transparency and an ability to play program material with wide dynamic range at life-like volume levels without a hint of strain. The sound is always clean, clear and effortless.

The drivers and tweeters used in Polk home speakers feature Dynamic Balance. As a result they all have the same sonic signature. This means that there is never a sense that different speakers are playing as the imagery shifts from speaker to speaker. The system creates a coherent, seamless sound stage that completely envelopes you in the action.

"The result (of Dynamic Balance) is a speaker system that is exceedingly smooth and free of resonant aberrations from top to bottom."
Widescreen Review, October 1996

THE GOOD

You're looking at a holographic "photo" of a Polk Dynamic Balance driver in motion. A perfect driver, such as one using our Dynamic Balance design, would look like a cake (flat on top)...like the photo you see above.

THE BAD

This is an example of what you DON'T want. The laser interferometry photo shows this driver is experiencing radial breakup...which results in performance-robbing resonance.

...AND THE UGLY

Yes, we believe we're making our point here! This photo depicts concentric breakup, which translates to distorted sound.