Genelec Oy

Flexound Audio Oy

Vesa Välimäki

Aki Mäkivirta

Matti Karjalainen

Poju Antsalo

Kari Kirjavainen

Jukka Linjama

Tommi Immonen

Jukka Lekkala

Seppo Uosukainen

Hannu Nykänen

Aki Kivivirta

A signal processing assembly is provided, the signal processing assembly comprising: a signal processing portion for deriving an output signal based on an input signal; and a control portion for controlling derivation of the output signal in the signal processing portion for rendering by a sound and vibration reproduction apparatus. The control portion is arranged to separately control respective amplifications for derivation of the output signal in a first frequency band and in a second frequency band, where the first frequency band represents tactile frequencies and the second frequency band represents audible frequencies, the signal control portion arranged to at least one of the following: determine a first amplification for the first frequency band in dependence of a user-selected second amplification for the second frequency band determine the first amplification for the first frequency band in dependence of a signal content type represented by the input signal.

Controlling reproduction of sound and vibration

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.

Method for designing a modal equalizer for a low frequency sound reproduction

The present invention relates to a method for designing a modal equalizer () for a low frequency audible range, typically for frequencies below 200 Hz for a predetermined space () (listening room) and location () (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 () by means of a digital filter by defining the filter coefficients on the basis of the properties of the modes. In accordance with the invention following method steps are used: forming a mode detection function (G(&#x3a9;)), defining the highest peak angular frequency &#x3a9;of the function (G(&#x3a9;)), making AR analysis of predefined order for solving the poles of the mode representing the highest peak angular frequency, selecting the pole closest to point eon the unit circle, determining the decay time of the mode and if is over a predetermined level, designing a modal correction filter for this mode, and repeating this procedure until no decay time exceeds over the predetermined level, and each individual filter obtained in previous stages of the method is combined to a cascaded filter.

Method for designing a modal equalizer for a low frequency audible range especially for closely positioned modes

The invention relates to a method and an equipment for attenuating sound in a duct. Sound propagating in a duct is detected by means of a detector () and attenuated by using two successive monopole elements () in such a way that both elements function as a dipole approximation and the elements are also used to approximatively produce the monopole radiation needed. A dipole control signal is fed to both elements () at a phase shift which is 180&#xb0; between the two elements. In addition, a monopole control signal is fed to the same elements (), only this time cophasally. Total volume velocities produced by the two elements () are combinations of the portions obtained from the monopole and dipole sources.

Method and equipment for attenuating sound in a duct

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Espoo, Finland

Vesa Välimäki