PMC Loudspeakers MB3 XBD-A Three-Way Active Studio Monitors - Pair

The PMC MB3-A with the XBD Extended Bass Cabinet for even more dynamic range.

The PMC Loudspeakers MB3 XBD-A takes the clarity and power of the MB3-A and adds the XBD extended bass cabinet devoted exclusively to bass. With an additional single 12-inch Radial bass driver, the twin-cabinet MB3 XBD-A system offers even better dynamics than the MB3, with an additional 3dB of headroom below the bass crossover frequency of 380Hz, and allows larger rooms to be driven with an even smoother frequency response, producing a maximum SPL of 129dB.

The twin XBD cabinets can be freestanding or soffit-mounted, and may be positioned vertically or side by side for greater flexibility. As with the MB3-A, a matching low-profile centre channel (MB3 XBD-C-A) is available for use in multi-channel arrays. Thanks to the wide-ranging frequency response of the twin-cabinet system, additional dedicated subwoofers are not a requirement.

MB3 XBD-A Key Features

• Type: 3-way ATL™ active reference monitor
• Frequency response: 20Hz-25kHz
• Power per channel: 3225W (HF 275W, MF 550W, LF 2400W)
• Effective ATL™ length: 2 x 3 metres
• Maximum SPL: 129dB

ATL - Advanced Transmission Line

PMC’s unique ATL™ (Advanced Transmission Line) enclosures have taken loudspeaker design to the highest level, using sophisticated cabinet construction, proprietary drive units, and patented absorption materials and techniques. The benefits are enormous compared to the relatively simple sealed and ported designs currently available elsewhere.

PMC’s innovative approach places the bass driver near one end of a long cavity ATL™ (the Advanced Transmission Line). This cavity is heavily damped with acoustic material specified carefully to absorb the upper bass and higher frequencies radiating from the rear of the bass driver. The lowest frequencies are allowed to pass down the line and emerge from the large frontal vent in the same polarity as the driver’s direct radiation, the vent acting essentially as a second bass driver. An important benefit of the approach is that the air pressure inside the cabinet, which loads the bass driver, remains consistent. This helps to maintain control of the driver over a wide frequency range and significantly reduces LF distortion. Consequently, the upper bass and mid-range detail is not masked by harmonic distortion and the result is PMC’s characteristically transparent mid-range, fast, dynamic bass, and outstanding clarity.

A further advantage of the ATL™ design approach is greater bass extension and higher SPL capability compared to typical ported or sealed designs of a similar size and driver specification. Moreover, the very consistent bass driver loading brings the welcome benefit that the frequency response remains consistent regardless of listening level, and analytical auditioning can be conducted without the need for high replay volumes to achieve an optimal bass response. This tonal consistancy at all output levels is a unique and very valuable characteristic of PMC’s Advanced Transmission Line.

Silent Cabinet

The highly engineered MB3 cabinets play an integral role in the overall superb performance of the loudspeakers. Aside from incorporating the Advanced Transmission Line itself, the enclosure has to be of a high standard to eradicate colouration and audible cabinet talk. Highly braced, resonance-damped Medite® is used with offset HF and MF drivers, radiused edges and acoustically absorbent StealthBaffles™ at the boundaries, as deployed in the QB1-A design, to minimise edge diffraction effects. These details were formulated with the aid of pioneering acoustic research and measurements undertaken by PMC in anechoic environments at the UK’s National Physical Laboratory, using opto-acoustic laser interferometry to map the soundfield and acoustic dispersion.

Sublime Highs and Mids

The MB3 features PMC’s hand-built, precision matched 34mm soft-dome HF driver and legendary 75mm fabric soft-dome mid-range driver, renowned for their natural, transparent sound and ultra-low distortion. The perforated acoustic lens on the high-frequency driver extends the treble response to well beyond the upper limit of human hearing, and controls dispersion to ensure close integration with the mid-range; the output of both drivers is meticulously combined to create an ultra-wide, stable image and entirely natural in-room response.

When designing the 75mm soft-dome, PMC’s aim was to create a driver capable of reproducing vocals, in particular, with unparallelled authenticity and transparency — but to high SPLs when required. Each handcrafted unit takes seven days to produce, and has to pass exceptionally tight matching and testing criteria. The result is an extremely clean, neutral and natural sounding mid-range driver, which means it can be used for long periods without inducing fatigue.

Deep and Meaningful Bass

High-performance bass drivers present serious engineering challenges. The power requirements, especially at higher SPLs, produce a rapid build-up of heat in poor designs. Heat is itself damaging to performance, causing power compression effects: rapid loss of efficiency, lower output levels and higher distortion. The Radial™ drivers employed in the PMC MB3 and BB6 are uniquely specified to drive ATL™ loudspeakers, using PMC’s own ultra-rigid, low-mass cone in a custom-built Radial basket. Not only is the chassis carefully constructed to conduct heat away from the driver’s voice coil, the design also vents hot air through the back of the driver assembly. In this way, heat is efficiently dissipated even when the speakers are operating at high level, ensuring that distortion is negligible, reliability stays high, and frequency response and performance remain consistent at all output levels — irrespective of how long the speakers have been in use.

The MB3 XBD-A is the next generation of PMC Main Monitors featuring their patented ATL technology and XBD extended bass cabinet. Call or chat with a RSPE representative today to schedule a demonstration and hear these PMC speakers for yourself.