Grand Class speaker system SB-G90M2
For surround-enriched musical playback, it is essential that the sound waves from each speaker arrive at the listener in precise alignment, regardless of their listening position. A point sound source design is one of the most effective ways to achieve this level of coherence.
Advanced Phase Precision Driver
A coaxial layout has been adopted to realize point-source sound reproduction, working together with a specially engineered phase-aligning bullet and a free-floating diaphragm to keep internal reflections to an absolute minimum.
The SB-G90M2’s coaxial two-way driver is dedicated to mid and high frequency reproduction, enabling precise imaging and an open, expressive sound, while upholding the point-source and linear phase philosophy that Technics has consistently refined.
Linear Phase Plug
A carefully contoured phase equalizer is positioned in front of the tweeter diaphragm to deliver finely detailed, high-resolution playback and a broad, immersive sound field.
The phase-equalizing “bullet” uses a modular structure and is crafted from dense brass, effectively suppressing excess resonance induced by midrange driver motion and ensuring clean, low-distortion treble.
Smooth Flow Diaphragm
As sound travels across surfaces, irregularities can cause interference, degrading the frequency response—this is particularly detrimental to short-wavelength high frequencies. The midrange cone section of the coaxial driver uses a gently profiled design with free-floating edges to reduce waveform deformation, suppress unwanted diaphragm noise, and achieve superb frequency and phase characteristics along with wide dispersion. The result is a spacious soundstage with rich, articulate mid and high frequencies.
Stationary Construction
To achieve music reproduction with a high signal-to-noise ratio, sources of stray noise have been rigorously eliminated. Building on the SB-G90’s driver fixing method, Technics further optimized the mounting system using computer-based analysis and developed a new structure that firmly secures each driver. At the same time, cabinet rigidity has been significantly improved to fully exploit the benefits of the balanced driver layout. The strength and geometry of every coaxial driver component has been carefully studied to curb vibration and undesirable resonances. Additional internal structures have also been introduced to create a dedicated sound path within the enclosure.
This innovative internal architecture effectively suppresses standing waves that generate resonant peaks.
Balanced Driver Mounting Architecture
Undesirable vibrations transferred to the baffle are further minimized by optimizing the air vent configuration through advanced computer simulations. The baffle that carries the woofer is rigidly linked to the base panel, enhancing overall structural stiffness. At the same time, the refined vent geometry improves the behavior of sound reflected from the cabinet sides, extending the overall response. The baffle supporting the coaxial unit is structurally separated from the woofer baffle to prevent mutual interference. Combined, these measures raise clarity and improve the depth and openness of the stereo image.
Standing Wave Termination Structure
Inside a loudspeaker cabinet, standing waves typically arise at specific frequencies determined by the enclosure dimensions, leading to problematic resonances. The conventional solution is to line the interior with absorptive material, but this can also attenuate frequencies outside the resonant bands, sometimes dulling the energy and realism of the music. As an alternative, the lower section of the woofer chamber in the SB-G90M2 incorporates a specially formed sound path that guides and terminates the standing waves responsible for resonance peaks, while requiring only a small amount of damping material. (Patented) This approach enables faithful musical reproduction, yielding natural, convincing sound—particularly in the mid and high frequency ranges.
