My speakers were made back when Focal was still marketing raw drivers to manufacturers and speaker component dealers, so I hope they're worthy of posting in the Focal thread even though they don't have a "Focal" logo on the cabinet exterior. (Sixty-seven percent of the driver compliment is made by Focal, 94% by driver weight, 70% by octaves
).
These are the Sterling Acoustics Acumen II, made by my small local company in 1989 using the Focal 8K415S woofer in a transmission line, and 5K013L midbass driver in an aperiodic chamber that vents into the t-line, and uses only the acoustic rolloff from the chamber, so no series capacitors on the midbass driver. (Tweeter is a modified Seas H400). The crossover is proprietary 2nd order, made with CAT caps, Litz wire inductors, non-inductive resistors, and wired with Kimber Kable. 51"H, 110#, ~ 89db sensitivity, 30-20khz. Each driver has it's own input, so they can be bi-amped or tri-amped. A modified pair of Dynaco 70s with the VTA driver boards and Tung Sol 7581A outputs being run as single channel monoblocks drive the midbass and tweeter. The signal for the woofers below 80hz and active subwoofer below 50hz pass through an active crossover and are driven by a vintage Kenwood solid state integrated amp....lots of flexibility with that setup.
I've enjoyed these speakers from the beginning. They replaced an impressive pair of Merlin 4B+ that I also liked, but the Sterlings have deeper more natural bass, and better midrange clarity and coherency (in my rooms and IMO). They're now in their 2nd home, and have improved with every system upgrade I've made. The tweeters got fresh ferro fluid in 2020, otherwise are all original. The only speakers I've heard that I liked as much or more were Magico S5 MkII, Avalon Ascents, and a modified pair of Hales...all driven by Convergent Audio Technology electronics. Much to my wife's dismay, I have no plans to get rid of these any time soon.
