Depth deploys the full array of MartinLogan's advanced subwoofer technologies to achieve deep, rich, satisfying bass while preserving electrostatic-like accuracy and detail. Its TriLinear™ BalancedForce™ alignment, advanced low-distortion switching amplifier, and sophisticated servo control system extract the very best possible performance from Depth's high-resolution 8-inch aluminum-cone drivers.
BalancedForce places the subwoofer's three drivers precisely 120 degrees apart from each other on the cabinet. Their reaction force vectors meet at the center and exactly cancel, virtually eliminating cabinet resonance and vibration. Gone with them are the cabinet-radiation coloration and bass blur that afflict even the best conventional subwoofers. The servo system, meanwhile, ensures that the output from the drivers themselves – the output we want – is always an absolutely faithful replica of the audio input signal.
Depth provides much of the performance of our flagship Descent subwoofer from a cabinet 30% smaller. It blends easily into any high-performance stereo music or multi-channel home theater system.
By eliminating cone flexure, even at long voice-coil excursions, aluminum diaphragms help our advanced-technology bass drivers achieve the very low distortion necessary for proper blending with MartinLogan electrostatic speakers.
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.
By operating three drivers in parallel, Depth benefits from the low distortion and optimal control of their 8-inch diaphragms while achieving the displacement and acoustical output of a 15-inch drive unit.
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.
Depth employs a novel BalancedForce configuration, in which three identical drivers are spaced precisely 120 degrees apart on the cabinet. Their reaction force vectors exactly balance at the center point for near-total cancellation, reducing spurious cabinet radiation by as much as 25 dB (a power factor of more than 300:1).
Depth offers six switch-selectable low-pass crossover settings between 30 and 80 Hz, each implemented with filters precision-designed for optimum attenuation slope and minimum group delay. This enables seamless integration with any MartinLogan main speakers as well as with speakers from other manufacturers.
At very low frequencies, all rooms exhibit a phenomenon known as room gain, which produces a mild bass boost. The smaller the room, the higher the frequency at which this starts. Depth's 25-Hz level control enables you to compensate for excessive room gain by cutting output in the 20- to 30-Hz range or, if you prefer, to accentuate the feeling of deep-bass energy by augmenting those frequencies.a name="amp">
Depth's amplifier belongs to recently developed class of switch-mode designs that incorporate a variety of innovative techniques to reduce noise, distortion, and heat to the lowest possible levels. In particular, the switching frequency is much higher than in typical subwoofer amplifiers of this type. It can produce a true 300 watts continuously and 500 watts peak.
Although ports are a convenient and cost-effective way of increasing low-frequency output, they rely on resonant energy in a way that impairs bass quality. A good sealed system will exhibit less transient-blurring group delay while maintaining smooth, consistent response regardless of output level or voice-coil temperature. Listen carefully to the sound of a bass drum, and you'll hear the difference.
Audio and video products available today represent a confusing myriad of connection options and setting configurations. Understanding this complexity, MartinLogan's team designed the Depth with an input architecture that easily integrates in both stereo and home theater systems. LFE input effectively uses no low-pass filter, instead leaving crossover control to the processor. Left/Right line level inputs integrate an audiophile grade low-pass filter. RCA output allows multiple Depths to operate in a serial configuration.
For home theater systems in which the surround processor supplies the crossover, Depth provides an LFE input that completely bypasses its internal filters. It also has an unfiltered line-level output to allow operation of multiple subwoofers in a serial configuration.
The Depth is supplied with sturdy, 3/8-16 ETC™ spikes, which can be used in place of the standard feet to enhance stability on thick carpets or to create tighter coupling between speaker and floor.
Let's face it – most subwoofer cabinets are just nicely finished boxes. That leads people to hide their subwoofers in corners behind plants or to buy models that look like end tables. Inspired by its three-driver TriLinear™ BalancedForce™ configuration, Depth's hexagonal form is both visually engaging and easy to integrate into a room. Available with either clear or black brushed-aluminum trim, it is as striking in appearance as it is in performance.