M60Xd Monitors Offers DSP Speaker Correction System
 November 1, 2004
On the heels of the company's introduction of
a DSP speaker corrected consumer loudspeaker system, NHTPro today announced the
recording industry's first near-field monitor to feature DEQX Calibrated DSP speaker
correction.
The system is the result of the combined efforts of three companies -- NHT, DEQX (Digital
Equalization and Crossover), and PowerPhysics -- that pooled their respective technologies to
develop a system that reduces distortion and improves on-and-off axis response far beyond
any currently available monitor.
Similar to the physical shape of the enclosure, the driver compliment is unique to the category.
A 6.5" woofer housed in the M60Xd monitor employs a magnesium cone that helps it achieve
the lowest distortion of any driver developed by the company to date. The tweeter is the same
driver used in NHT's A-20 powered monitor, but unlike its predecessor, the
M60Xd is bi-amplified, and all crossover functions are managed by the XdA DSP
processor/amplifier.
The outboard XdA contains the DEQX DSP processor, four amplifiers, and a power supply.
Inputs/outputs include line and balanced (XLR) inputs, four powered outputs to power the biamplified
monitors, plus two line and balanced outputs for adding subwoofers. Additionally, the
XdA is "future proof" thanks to the addition of a USB 2.0 port and a microphone input, both of
which are designed for upcoming upgrades. Unlike other amplifiers, the XdA features only
three controls: a rear panel switch for either stereo or mono bass output, and respective
channel boundary controls to compensate for monitor placement artifacts.
Australia-based DEQX developed a processing scheme that corrects loudspeaker behavior,
primarily in the midrange frequencies where the ear is most sensitive. With the DEQX design,
digital crossovers up to 300dB per octave allow optimization of each driver's performance
within its operating range. The steep slopes reduce phase anomalies, providing virtually
identical on-and-off axis response, in addition to correcting frequency response. In spite of
real time processing, the system, as designed, boasts very low latency -- less than 10ms.
In addition to flat response, the XdA is fully
upgradeable. In the near future, NHTPro will offer a room correction module and a variety of
application-dependent filter sets, all of which can be downloaded to the XdA via its USB port.
The XdA features four internal monitor amplifiers developed by Power Physics of California,
featuring the company's patented One Cycle Sound, class D design, rated at 150 Watts RMS,
600 Watts peak. The amplifiers are small and 96% efficient, producing little heat but with less
than .05% THD across the frequency spectrum at full power. A 600 Watt switching power
supply contained in the XdA is power factor-corrected, maintaining spec at virtually any
voltage.
The XdA's chassis measures only 1 ru and weighs less than 12 lbs. The M60Xd monitor
measures 15" (H) x 13" (W) x 10" (D) and weighs 18.2 lbs. Each monitor is shipped with four
conductor cables measuring 25' each, terminating with a custom four-pin banana connector.
A custom rack mount shelf is included as well.
Later in 2005, NHTPro will ship the matching S-60 subwoofer. The S-60, featuring a dual 12"
enclosure, will be powered by an outboard 500 Watt amplifier that connects to the XdA, while
all controls (phase, level, and crossover) will be managed by the DSP software's user
interface.
NHTPro's M60Xd system will be available direct from the manufacturer in Q1 2005. MSRP for
a two channel monitor system is approximately $4500. For more information, visit their web site at www.nhtpro.com. | 
