Abstract: In the invention there is being combined the back cavities of two speakers so that one speaker is used as a general speaker and the other one provides a boosting effect to the general speaker. For example, the other speaker can act as a subwoofer to the general speaker. The back cavity of the speaker is extended by a tubular cavity. The tubular cavity can extend to either the front or back panel of the mobile phone, thereby boosting the other speaker located at the respective panel.

Abstract: The present invention relates to a catalyst comprising a honeycomb (1) and a surrounding jacket, the honeycomb comprising a structure formed of a stack of metal sheets, of which at least part are profiled, and the honeycomb structure including several through-flow channels for gas. The free ends of the said metal sheets are distributed over a part (S1) of the honeycomb periphery unsymmetrically to the center of the honeycomb so that part (F1) of the honeycomb's periphery is free from the free ends of the metal sheets. The said honeycomb is attached either directly or through an intermediate layer to the said jacket over an area (L1) comprising at least part of the said free ends.