Floorstanding loudspeakers — Pbn Audio M1!5

PBN Audio built the M1!5 as a floor-standing model for its M Series. The firm was founded by Peter B. Noerbaek, who brings more than 30 years in audio to the design. It was introduced as a more compact companion to the M2!5, and it takes the compression driver approach of that larger model into a smaller cabinet. A pair has been priced at NZD 32,000.

Key specs that matter

Two 12 inch woofers cover the low range, and a 1 inch compression driver on a waveguide handles the upper range with dispersion of 90 degrees horizontally and 50 degrees vertically. The crossover uses a 1.2 kHz LKRY 6th order high pass and a 1.3 kHz Butterworth 5th order low pass. Sensitivity is 94 dB at 2.83 V and 1 metre, with a nominal impedance of 4 ohm. PBN lists a range of 30 Hz to 25 kHz and power handling of 300 W. The cabinet measures roughly 36 cm wide, 48 cm deep and 108 cm tall, and each speaker weighs 70.3 kg.

Engineering and use context

The woofers were designed by an outside engineer in close work with Noerbaek, and PBN describes them as an advanced version of the driver used in the earlier model. The compression driver shares its phase plug with the unit in the M2!5. Its narrower vertical pattern reduces energy sent toward floor and ceiling, while the wider horizontal spread covers a normal seating area. Using different filter types on the two sides of the crossover, with slightly offset points, lets the designer shape the overlap between woofers and horn. The network is charge coupled with 27 V DC, which PBN applies across the whole M Series to hold its crossover capacitors under a constant bias. Given its mass and height, moving and placing each cabinet is a job for two people. Veneers and finishes are chosen when the pair is ordered, and PBN offers custom speaker builds as well.

Pairing

With this sensitivity the M1!5 needs less power than most speakers of its size to play at normal levels, though the low nominal load still needs an output stage comfortable with low impedance. The power handling also accepts powerful transistor amplifiers. PBN makes its own amplifiers and turntables, which gives a single-brand route for buyers who want one.

Alternatives

The PBN Audio M2!5 is the larger floorstander of the M Series, with two 15 inch woofers per side, 95 dB sensitivity, a range of 25 Hz to 20 kHz within 2 dB and a weight of about 127 kg.