Keystone Speaker

Keystone is the primary stand-mount loudspeaker project within 3SB Audio.

Early Keystone work explored an experimental MTM cardioid architecture intended to deliver substantial low-frequency control and system integration in a domestic stand-mount format.

The initial configuration used a Seas 27TBCD/GB-DXT tweeter, dual 12MU/4731T00 midrange units, and Dayton DCS165-4 woofers.

A second iteration replaced the Seas tweeter with a Scan-Speak D3004/604000 beryllium tweeter and swapped one of the 12MU midrange units for a Scan-Speak 15WU midwoofer.

Research Role

Keystone established many of the core technical questions for the broader project portfolio: directivity matching, driver allocation, compact cardioid loading, and the practicality of assigning dedicated amplification and DSP to every acoustic path.

The model shown here represents an early exploration phase rather than a final production geometry. The project continues to inform later loudspeaker work across 3SB Audio.

Design Reference

Current cabinet development is maintained in Onshape as a working reference model rather than a fixed manufacturing release. Dimensions, hardware allowances, and assembly details continue to evolve with the project.