Abstract: The present publication describes a data transfer method and system in a digital sound reproduction system. The method comprises method steps for generating a digital audio stream for multiple channels in a host data source, e.g. a computer (1), the audio stream is formed by multiple consecutive samples, receiving the digital audio stream sent by the host data source (1) through a digital data transmission network by several digital receivers (2) each of which including a microcontroller with a clock, the receivers (2) further including means for generating an audio signal.

Abstract: The present publication describes a calibration method and apparatus, in which an electrical calibration signal is formed, an audio signal is formed in the loudspeaker from the calibration signal, the response of the audio signal is measured and analysed, and the system is adjusted on the basis of the measurement results. The calibration signal is formed in the loudspeaker in such a way that it is essentially a sinusoidal signal, the frequency of which scans at least substantially through the entire audio frequency range.

Abstract: A method and means for a sound-reproduction system. The means include a first opening arrangement for a microphone, and a second opening arrangement for a microphone stand, formed in an essentially planar elastic material.

Abstract: In a room with strong low-frequency modes the control of excessively long decays is problematic or impossible with conventional passive means. In this patent application a systematic methodology is presented for active modal equalization able to correct the modal decay behaviour of a loudspeaker-room system. Two methods of modal equalization are proposed. The first method modifies the primary sound such that modal decays are controlled. The second method uses separate primary and secondary radiators and controls modal decays with sound fed into at least one secondary radiator. Case studies of the first method of implementation are presented.

Abstract: An identification method and apparatus in a sound-reproduction system, in which an electrical calibration signal is created, an audio signal is created in the loudspeaker from the calibration signal, the response of the audio signal is measured and analysed, and the system is adjusted on the basis of the measurement results. A light signal is created in the loudspeaker with the aid of a centralized control system, in order to indicate visually the loudspeaker that is the subject of the calibration.

Abstract: The invention relates to a reflex loudspeaker construction (1, 2, 3), which comprises a loudspeaker chamber (30) delimited by the reflex loudspeaker construction (1, 2, 3), a reflex channel (5) connected to the loudspeaker chamber (30), which connects the loudspeaker chamber (30) to the external space of the reflex loudspeaker construction (1, 2, 3), and at least one loudspeaker element (7) connected to the reflex loudspeaker construction (1, 2, 3), which forms part of the structure delimiting the loudspeaker chamber (30). According to the invention, the reflex loudspeaker construction (1, 2, 3) comprises at least two components (2, 3), which can be repeatedly detached at least partly from each other, without dismantling, in order to use the loudspeaker chamber (30) as a transportation space.

Abstract: A method and apparatus in a sound-reproduction system, in which method an electrical calibration signal is formed, an audio signal is formed in the loudspeaker from the calibration signal, the response of the audio signal is measured and analysed, and the loudspeaker system is adjusted on the basis of the measurement results. The operator is permitted to made additional alterations to the settings of the loudspeaker system on the basis of the measurement performed, the effects of the alterations are calculated and displayed to the operator without additional measurements, and the additional settings are implemented in real time in the loudspeaker system.

Abstract: The present invention relates to a method for designing a modal equalizer (5) for a low frequency audible range, typically for frequencies below 200 Hz for a predetermined space (1) (listening room) and location (2) (location in the room) therein, in which method modes to be equalized are determined at least by center frequency and decay rate of each mode, creating a discrete-time description of the determined modes, and determining equalizer filter coefficients on the basis of the discrete-time description of the determined modes, and forming the equalizer (5) by means of a digital filter by defining the filter coefficients on the basis of the properties of the modes.

Abstract: The loudspeaker construction comprises a loudspeaker chamber delimited by a loudspeaker enclosure structure, a reflex duct communicating with the loudspeaker chamber so as to connect the loudspeaker chamber to the exterior environment of the loudspeaker enclosure, and at least one loudspeaker unit mounted on the loudspeaker enclosure structure so as to form a portion of the delimiting walls of the loudspeaker chamber. According to the invention, the loudspeaker enclosure structure comprises a curved spiral structure closed from its both sides by gable elements so as to form the loudspeaker chamber, and the reflex duct is adapted at least partially running on the outer periphery of the spiral structure.

Abstract: A method and apparatus for attenuating acoustic reflections related to sound radiated by a loudspeaker in an acoustic space. According to the method, at least one cancelling loudspeaker is used for radiating a canceling sound in the space. The signal required for producing the cancelling sound is sampled from the sound reproduction apparatus prior to the processing of the original sound signal for emission into the acoustic space. The sample signal is low-pass filtered, delayed, amplified and inverted prior to being taken to the cancelling loudspeaker. The sound reproduction apparatus includes a signal sampling device, control devices, and at least one cancelling loudspeaker for radiating the cancelling sound.

Abstract: The present invention concerns the reduction of vibrations of a loudspeaker enclosure caused by the mechanical vibrations of the dynamic loudspeaker element by virtue of attaching one or more additional masses to the loudspeaker driver unit using elastic and lossy means. The masses with their elastic attachments dimensioned according to the present invention resonate at frequencies excited by the vibrations of the loudspeaker element at frequencies where the reduction of the amount of vibration is desired. The magnitude of vibration coupled to the enclosure of a loudspeaker modified according to the present invention is significantly smaller than that of a conventional loudspeaker. Furthermore, it is technically and economically advantageous to implement the reduction of mechanical vibrations according to the present invention.