Directional character and noise cancellation is of increasing importance in open-air events and is also known to help produce sound more accurately in reverberant environments such as concert halls and sport arenas. The key feature of Passive End Fire Technology compared to prior ways of obtaining directional low frequency reproduction is considerably higher acoustic output in front of the speaker system with exceptional transient capability. A single enclosure bass loudspeaker systems typically have a very low directivity because of the large wavelength which is to be radiated to produce sound in bass region which equals wavelengths from 10m to 3m. To have a directional character comparable to these wavelengths the enclosure and particularly the radiating surfaces need to be around the same size which would make them difficult to carry or install in most environments such as indoors or limited space outdoor facilities. There are several approaches already known which can be used to improve the directivity of sound sources. One option is to use open back enclosure or have two separate sound sources in which case one sound source radiates to listening direction and other sound source to the opposite direction. When inverting the polarity of the sound radiating opposite direction with addition of delay one can create directional radiating character. It is also known to use to sound sources (two or three units) in a row and delay the front one(s) to match the propagation time difference due to distance. When used in relation to quarter wavelength compared to sound wave radiated by the speaker system this arrangement is known to cancel the sound wave by half wavelength distance when observing behind the row of speakers, ie. opposite direction of radiation pattern. The revolutionary Passive End Fire Technology is based on providing a loudspeaker system in which loading in front radiating sound source with internal propagation time difference compensates the time difference of the sound wave radiated from opposite direction radiating sound source arriving to the front. This is achieved with horn-like loading at the front side which has the same phase behavior as the reflex-loaded enclosure facing back. No additional delays or processing is needed so only amplifier channel is enough to drive the whole subwoofer!