Rockin’ Ribbon Tweeters using a thin metal ribbon have been around
for decades, but can they stand up to the demands of today’s listening
habits?
Ribbon tweeters have always been kind of like the loudspeaker equivalent of a
butterfly. Beautiful, yet fragile in the extreme. Typically, they have been most
popular with those who value quality over quantity, where letting it rip might
involve winding up the volume a bit during the finale of Beethoven’s Ninth,
rather than trying to make our ears bleed while watching 2 Fast 2 Furious.
 | BG Corp, the speaker company formerly known as Bohlender-Graebener, uses ribbon
tweeters to produce high frequencies. Ribbon drivers are known for their
quality, not quantity, meaning they sound great but don’t play loud. |
A
driver, like a ribbon, that is much taller than it is wide is usually called a
line source, and in the case of the BG R-17i we have a tweeter ribbon that is
about 2 inches long, but less than a half inch wide. Tweeters will start to
exhibit limited dispersion when they become larger than about an inch in any
dimension, and a line source like the BG ribbon will have excellent dispersion
across its short dimension, but will be quite directional above and below the
longer axis. Designers will take advantage of this phenomenon to create a
speaker that can cover a wide lateral range of seating locations, yet
deliberately restricts the amount of high-frequency energy reflecting off of the
floor and ceiling. In other words, this means that a ribbon tweeter can reduce
the contribution of the room to the sound, resulting in clearer, less muddled
music and movie effects.
Because of this unusual directionality, the ribbon
tweeter in the R-17i can rotate 90 degrees, should you plan to mount the speaker
on its side for use as a center channel. Flanking the ribbon is a pair of 4-inch
woofers, followed by a pair of 4-inch passive radiators. Covering everything is
a semicircular perforated silver (black is an option) metal grille––resulting in
a wall-mounted R-17i looking a bit like a half section from some futuristic
piece of pipe.
