OTHER TECH

Tucked beneath a window in the lower cabinet's glass faceplate is an LED display, which, along with a remote control, makes up the speaker's user interface. The amps are mounted on an extruded, multi-finned heat sink near the terminal panel, which has two XLR connectors that link the upper and lower units, plus two coaxial digital inputs, a proprietary connector for communicating with other Meridian gear, and an RS-232 port for software updates. The speakers operate in a master-slave fashion and are connected by a single coaxial digital cable.

The circuit board inside the back of the bass cabinet has two coaxial digital jacks, which can handle sampling rates up to 96 kHz. (Support for 192-kHz rates is planned.) A crystal clock retimes the digital signal to minimize jitter, then passes it along to a series of programmable logic arrays, which handle signal upsampling, tone control, and volume scaling before sending the signal to a pair of Motorola DSP (digital signal processing) chips. Along with performing a variety of preamp-style acoustic manipulations, including volume, tone, and balance adjustments, the chips implement the electronic crossovers, where digital filters split the frequencies into bass, midrange, and treble bands.

Beyond basic bass and treble controls, the DSPs offer some unusually sophisticated adjustments. For example, balance can be fine-tuned using either level or delay adjustments on one channel to accommodate off-axis listening, while a "tilt axis" adjustment controls the vertical alignment of the tweeter/midrange frequencies, "tilting" them relative to your sitting height.

Once the signal is split into the various frequency bands, the processed digital data streams are fed to four 196-kHz/24-bit D/A converters, where the signals are converted to analog on their way to the power amplifiers: three 100-watt amps for the three woofer pairs and two 100-watt amps for the tweeter and midrange. Eight large, high-quality capacitors and a pair of large toroidal transformers anchor the power supply, while an onboard computer runs Meridian's proprietary communications network. Although Meridian's DSP-series speakers are designed to be connected directly to a digital source, they can also be used with preamp/controllers that can provide digital output signals.

If you imagine that a system this sophisticated is expensive, you're right: the DSP 8000s cost $54,000 a pair. But you can get a taste of Meridian's active technology in the DSP3100s, bookshelf models with a more forgiving $4,800 price tag.

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