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Bursting with Innovation and Low Bass Performance
MartinLogan's Depth i powered subwoofer packs Descent i's innovative technology into a cabinet that's a full 40 percent smaller. Depth i brings deep, powerful bass to any audio system, whether for high-end stereo music listening or multi-channel home theater. Its three-driver, force-canceling configuration virtually eliminates cabinet resonance and the resulting bass blur that plagues conventional subwoofers, while sophisticated amplifier and triple-servo control technology ensure the purity and accuracy of the sound from the drivers.
Depth i 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 900-watt peak power switching amplifier, and sophisticated triple-servo control systems extract the very best possible performance from Depth i's high-resolution 8-inch aluminum-cone drivers.
Eliminating Cabinet Resonance and Vibration
TriLinear BalancedForce places the subwoofer's three drivers precisely 120 degrees apart from each other in 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 triple-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 i provides much of the performance of the company's flagship Descent i subwoofer from a cabinet that's 40 percent smaller. It blends easily into any high-performance stereo music or multi-channel home theater system. In fact, with its easily accessible top-mounted controls and separately configurable LFE and two-channel inputs, Depth i's performance can be independently optimized for home-theater and stereo operation in the same system.
Rigid, Low-Mass Aluminum-Cone Diaphragms
By eliminating cone flexure, even at long voice-coil excursions, low-mass yet extremely rigid aluminum diaphragms help the advanced-technology bass drivers achieve the very low distortion necessary for proper blending with MartinLogan electrostatic speakers.
TriLinear™ Driver Array
By operating three drivers in parallel, Depth i benefits from the low distortion and optimal control of their 8" diaphragms while achieving the displacement and acoustical output of a 15" drive unit. And because the thermal load is distributed over three voice coils instead of concentrated in one, the system is less influenced by temperature-induced compression.
BalancedForce™ Driver Alignment
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 identical drivers in exact opposition to one another, so that their forces on the cabinet almost perfectly cancel.
Employing a novel application of the BalancedForce principle, Depth i locates the three drivers of its TriLinear™ array 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).
Triple-Servo Correction System
A highly sophisticated triple-servo control system for each driver compares input to output and applies automatic electronic correction for any deviation. These advanced servos combine with the drivers' inherent low distortion and their BalancedForce™ reaction-canceling alignment to yield the cleanest, most accurate bass possible.
Comprehensive Inputs and Outputs with Simultaneous-Connection Option
Depth i provides a direct, unfiltered LFE input for connection to surround preamp / processors and receivers with built-in subwoofer crossovers as well as line- and speaker-level stereo inputs that connect to its internal crossover. The LFE and stereo inputs can be connected simultaneously with separate level and crossover settings for each, enabling precise optimization for home-theater and stereo music playback in the same system. For those who desire a multiple subwoofer setup, line-level outputs include a mono jack that carries the sum of all inputs. Further, stereo outputs pass a signal from the stereo inputs either directly or through switch-selectable high-pass filters.
Top-Mounted Controls
It's a lot easier to dial in exactly the right settings when you don't have to get down on your hands and knees to reach the controls. Depth i's top-mounted controls, discreetly hidden beneath an aluminum cover inset into the cabinet, take the drudgery out of performance tweaking.
Precision Low- and High-Pass Crossover Filters
Depth i offers six switch-selectable low-pass crossover frequencies between 30 and 80 Hz, implemented with filters precision-designed for optimum attenuation slope and minimum group delay. This ensures cohesive integration with smooth response through the crossover range with any type of main speaker. The similarly designed high-pass filters on the line-level outputs can be switched between 40- and 70-Hz settings or bypassed. An optional internal module will be available with low-pass filtering custom tailored to the MartinLogan CLX full-range electrostatic loudspeaker.
25-Hz Level Control
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 i'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.
Extended-Range Master Level Control
Crave a little heavy-metal thunder from time to time? Ordinary level controls top out at '10'; MartinLogan's goes to '11'!
Full-Rotation Phase Switch
Depth i's phase control can be switched from 0 to 270 degrees in 90-degree increments, allowing precise adjustment for optimum blending with the main speakers.
Advanced Proprietary Vojtko™ Switching Amplifier
Depth i's amplifier belongs to a 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 350 watts continuously and 900 watts peak.
Sealed Cabinet with Asymmetrical Driver Chamber
Depth i's sealed cabinet eliminates port and passive-radiator resonances and minimizes low-frequency group delay. And its internal asymmetry breaks up standing waves within the enclosure to further minimize resonance and coloration.
Asymmetrically Configured Energy Transfer Coupler Spikes
Depth i is supplied with sturdy, 3/8" ETC™ spikes, which can be used in place of the standard feet to enhance stability on thick carpets or to create tighter coupling between subwoofer and floor. The spikes are arrayed asymmetrically in a configuration designed to minimize the chance of grille damage if the cabinet is tipped.
Aesthetically Extraordinary (Yet Practical) Cabinet Design
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. Depth i's cabinet is the anti-box, with a unique architectural look that is both visually engaging and easy to integrate into a room. It features a selection of wood finishes for the top, which enable the Depth i to blend into any décor. The cabinet body, meanwhile, has a durable, black tough-coat finish, with rubber bumpers at the bottom to minimize damage from stray impacts, such as vacuum cleaners and errant footsteps. Durable, crushproof grilles complete the package. | 
