A favorite trick for demonstrating how dramatically BalancedForce® reduces cabinet vibrations (and the resulting non-linearity) is to balance a nickel on end atop the subwoofer. The nickel will continue to stand up-right during even the loudest bass passage.
Three Woofers in a BalancedForce® TriLinear Configuration
CLX's unique DualForce double diaphragm, triple stator dipole low-frequency electrostatic transducer delivers deep, dynamic bass with twice as much force as a standard ESL. Additionally, CLX's low-frequency dipole stabilization technology reduces low frequency rear wave cancellation inherent to dipole transducers. This is accomplished by increasing the air path length behind the CLX and delaying the out-of-phase back wave. The resulting decrease in low-frequency front-wave cancellation increases overall output while minimizing total harmonic distortion at low frequencies.
MartinLogan PoweredForce woofers feature advanced driver and amplification technologies that deliver astonishingly dynamic and articulate bass from enclosures only about the size of a case of wine. Integrated low-frequency equalization further enhances performance by allowing precise tailoring to individual room acoustics.
Controlled Dispersion PoweredForce woofers tailor woofer output to provide a low-frequency dispersion pattern at the crossover point mimicking that of our Controlled Dispersion XStat transducers. This breakthrough design provides dynamic, room filling bass at the lowest frequencies. However, by subtly shifting woofer output as it approaches the crossover frequency we minimize side-wall reflections and reduce problematic room interactions, while achieving seamless integration between the woofer and electrostatic transducer. Low-frequency equalization further enhances performance by allowing precise tailoring to individual room acoustics.
Conventional subwoofer enclosures vibrate in reaction to driver activity, creating a secondary and highly colored sound source. In extreme cases, the cabinet may even "dance" on the floor. The typical expedient of adding mass can make the problem less obvious, but it doesn't really make it go away. Resonant bass smear is inevitable unless cabinet vibration is drastically attenuated. MartinLogan's BalancedForce design places multiple drivers in exact opposition to one another, so that their forces on the cabinet almost perfectly cancel, reducing spurious cabinet radiation by as much as 25 dB.
By operating three drivers in parallel, Descent and Depth benefit from the low distortion and optimal control of single drive units while achieving the displacement and acoustical output of a drive unit three times larger.
All dynamic drivers have nonlinearities in their suspension and motor systems, which increase dramatically at large diaphragm excursions. The resulting distortion can rise to 20 percent or more with typical woofers and subwoofers reproducing strong deep-bass signals. MartinLogan's advanced servo system uses a sophisticated monitoring and control circuit to detect and instantaneously correct any deviation between acoustical output and electrical input. The result is a three- to ten-fold reduction in distortion for the purest possible low-frequency reproduction.