Floorstanding loudspeakers — Mbl 111 F

The 111 F is a four-way floorstanding Radialstrahler from the German maker MBL, classed as part of its Noble Line. It combines the omnidirectional tweeter and midrange units of the larger MBL models with a conventional bass section split into two separate enclosures. MBL quotes EUR 49,000 per pair in Germany, and the North American list price is USD 55,900 per pair.

Key specs that matter

Two Radial units cover the upper range - an HT37 tweeter made of unidirectional carbon fibre and an MT50 midrange made of woven carbon fibre. Below 650 Hz, a pair of 150 mm aluminium cones takes the low midrange, and below 170 Hz two 220 mm aluminium woofers carry the bass. The top crossover point is 3,500 Hz. MBL gives 38 Hz as the lowest frequency, and each speaker weighs 64.5 kg. The acoustic centre sits 107 cm above the floor. The earlier hybrid generation of the 111 F has a cabinet of 450 x 1,130 x 565 mm, or 1,205 mm tall with the cover fitted, plus a range of 24 Hz to 40,000 Hz, a maximum linear output of 106 dB and fourth-order Linkwitz-Riley filters.

Engineering and use context

The two woofers occupy a reinforced 58 litre bass reflex box and sit on its side walls, facing away from each other. An aluminium rod joins their magnet systems, so as both cones travel outward and inward together the reaction forces on the cabinet oppose and largely cancel. The low midrange drivers repeat that layout inside a sealed 14 litre chamber that is decoupled from the bass volume. Above them the radial units have no box at all - their carbon lamellae flex to radiate around a full 360 degrees horizontally. The crossover includes a passive high-pass section and a two-pole subsonic filter that limits woofer travel at the very bottom. MBL describes the bass section as pressure-chamber loading and the low-midrange pair as force-balanced chassis. Finishes are piano black or piano white, each paired with gold or chrome trim, and MBL offers custom colours on request. The warranty period is five years.

Pairing

MBL rates the 111 F at 4 ohm nominal with a power handling of 340 W and a peak rating of 2,200 W. The earlier generation is rated at 83 dB for 2.83 V at 1 m. The maker states the speaker suits any room size and is optimal in rooms up to about 60 m2.

Alternatives

The MBL 116 F uses the same driver set and crossover points in a smaller 46 litre bass cabinet, weighing 42 kg and reaching 40 Hz.