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Product Image MB Quart RK1-113 Reference 5.25″ 2-Way Coaxial Speakers – Pair

MB Quart RK1-113 Reference 5.25″ 2-Way Coaxial Speakers – Pair



MB Quart RK1-113 .75” titanium dome tweeters utilizing WideSphere™ Technology for exceptional musical reproduction of high frequencies are the heart of the system. The innovative tweeter design develops an off-axis dispersion pattern that creates a larger sound stage which brings a concert in your car to life.

Cone Material

The MB Quart RK1-113 speaker is engineered with a Lightweight Curvilinear craft pulp with bamboo fiber cone. This design adds strength and superior bass frequency reproduction. This means that midrange and bass frequencies remain very musical without the distortions that can be caused by the cone flexing. With the curvilinear design the geometry is specifically engineered for best upper band midrange response, which is critical for frequencies that are responsible for vocals and acoustic instruments like piano, guitar and percussion.

Surround / Cone Coupling

High temperature adhesives are utilized to keep the coupling from cone to surround fused. Adhesives are also impervious to cold weather.


Molded Polymer Sealing gaskets are utilized to keep the speaker isolated from the mounting surface and improve protection from water and dust intrusion.

​Voice Coil / Former Assembly

High temperature imported wire on Kapton former. The MB Quart RK1-113 former is lighter than a standard speaker which allows the component to support slightly higher frequency extension and efficiency.


Red woven fiber cotton poly blend spider to stabilize the cone and voice coil in all musical situations.

Cooling System

Venting allows air passage through the spider and speaker frame ribs to exchange air over the voice coil.


MB Quart RK1-113 Reference coax (2-way) designs feature a built-in audiophile crossover which guides the frequencies from the amplifier to each driver (speaker). This system is designed with tight tolerance components for superb sound quality.


Aerospace grade PA66 composite with 30% glass fiber speaker frame to assure that no harmonic distortions affect the tone of the speaker.