ATL 911



  • Manufacturer: ATL Elektro Akustik Vertriebsgesellschaft mbH
  • Model: 911
  • Year of manufacture: 1992-94
  • Made in: Germany
  • Colour: all RAL-colours possible
  • Dimensions: 14 x 104 x 29,2 cm (W x H x D) + base: 22 x 29,5 cm
  • Weight:
  • New price approx:

Technical Data

  • Construction: 3-way bass reflex with side woofer (L-/R-pair) and bass reflex opening on the baffle.
  • drivers:
    • flat diaphragm woofer: 210 x 210 mm.
    • 2x cone midrange driver: 100 mm diameter with 25 mm voice coil
    • Tweeter magnetostat (linear field transducer): 170 x 40 mm
  • Power handling (nominal/music): 90 / 130 Watt

efficiency: 88 dB (SPL Watt/1 m)

  • Frequency response: 24-26000 Hz ± 3 dB
  • Crossover: 250 / 4500 Hz (12 dB/oct)
  • bass self-resonance 3 Hz
  • Impedance: 4 Ohm

Source: ATL brochure

Special Features

  • Linear field transducer

The diaphragm of this tweeter consists of an extremely thin aluminium foil with five directionally oriented conducting paths, which oscillates back and forth in front of the air gap of a very strong magnet. Extremely fast impulses, as well as unique airy and detailed high frequency reproduction are the result.

  • Bass power

The square woofer of the 911 has a membrane made of hard foam, which is coated with two layers of high-strength special paper in the same colour as the cabinet. Due to its low dynamic mass, this resonance-free sandwich construction, together with the generously dimensioned voice coil, produces an exceptionally fast onset and decay, resulting in clean, fast and deep bass.

Source: ATL brochure


Like all drivers with foil cone, the tweeter of the 911 is subject to ageing, which is particularly evident in the increase in impedance of this type. Normally the impedance of a linear transducer of this generation is 2.6 to 2.8 ohms.