STIG CARLSSON. SPEAKER, Sonab OA-6 type 2, a pair, 1970s.

Width 24, depth 43, height 68 cm, weight: 20 Kg Principle: Bass reflex. (double pipes) Omnidirectional. Built-in power amplifiers ("bass-energizers") that drive the "bass".
The stage has negative internal output resistance and frequency-dependent feedback and compensates the tone curve of the bass elements electronically. Built with silicon transistors. Tone controls adjust the bass curve.
Impedance: 8 ohms (Increases to 100 ohms in the base to load the amplifier less) Frequency range: 26-18,000 Hz Tone curve: 29-15,000 Hz +/- 3dB on floor to wall Splitting frequencies: 200, 2700 Bass element: 1pc 22 cm 8 ohms Philips 9710 broadband element.
Midrange: 1 x 22 cm 8 ohm Philips 9710 broadband element, mounted in its own cavity.
Tweeter elements: 4 pcs 5 cm 8 ohms Peerless MT 20 HFC Connection: Canon XLR Power consumption: 50VA.