Abstract: A loudspeaker based on a dipole element (DE) with at least one diaphragm arranged to generate an acoustic dipole signal according to an electric signal, e.g. a dedicated dipole driver such as an Air Motion Transformer or a combination of two monopole drivers, e.g. dome tweeters, mounted back to back close together. An acoustic waveguide (WG) is arranged in relation to the dipole element (DE) such that a surface (S) of the acoustic waveguide (WG) is close to the at least one diaphragm of the dipole element (DE). The acoustic waveguide (WG) extends in both directions of a main axis (MA) of the dipole element (DE), thus serving to guide the acoustic dipole signals away from the dipole element (DE). Preferably, the surface (S1, S2) of the acoustic waveguide (WG) has a general tilt of less than 30° in relation to the main axis (MA). Thereby, a diffuse sound field is provided with only a limited requirement for housing the acoustic waveguide (WG) in the depth dimension.

Abstract: A method for controlling vacuum in an intake conduit of a combustion engine in a vehicle is provided. The vehicle is provided with a brake booster and an actuator for actuating the brake booster. Actuation of the brake booster causes a throttle valve in the intake conduit to close creating a vacuum to the brake booster.

Abstract: A method of adapting the ignition timing in an internal combustion engine to the crankshaft position depending on variations in engine rpm, load and overlap between the inlet and exhaust valves. The ratio between combusted and non-combusted gas in cylinders is computed, and this ratio is utilized, in such a way that the greater the proportion of combusted gas there is, the earlier the ignition will be initiated. The invention also relates to an engine with a control unit and means for computing said ratio and controlling the ignition timing.