Floor Loudspeaker Reviews

Sidebar 3: Beryllium

Valued for its combination of light weight and rigidity—it's seven times stiffer than titanium or aluminum—beryllium is used in the production of tweeter domes and midrange drivers by a number of high-end speaker manufacturers, including Focal. But, unlike manufacturers whose "beryllium" tweeter domes are actually made of an alloy containing, according to some reports, as little as 2% of the element, Focal's beryllium cones and domes are 100% beryllium. The use of beryllium makes possible the extension of the frequency response of Focal's tweeter to 40kHz, while minimizing unwanted resonances.

Focal is forthright in warning buyers of the potentially toxic effects of beryllium when not handled carefully. The package of ancillary materials included with the Kanta No.2 includes a pamphlet, Beryllium: Precautions for Use. There the user is warned that "tweeters including the beryllium dome should be handled with caution, and, generally, speakers should be kept out of reach of children, especially the access of the tweeters and the dome of beryllium"; and "to ensure that the protective grille and all protective means on the tweeter is well maintained." According to this pamphlet, "the risks are limited, being specified that the hazardousness of beryllium mainly results from its inhalation, ingestion, contact in vapour form or microparticles." In the event of damage to the beryllium dome, you're warned not to touch it, to cover the tweeter and any broken parts with the provided adhesive strip, and to contact your Focal dealer.

For more information about Focal's use of beryllium, contact beryllium@focal-fr.com.— Robert Deutsch