Vol.1, No 3, 1998 pp. 51-58
UDC:699.84
NOISE REDUCTION IN ROOMS
USING ACTIVE AND PASSIVE CONTROL
ON THE BASIS OF MODAL ANALYSIS
Miroslava A. Milošević, Nenad D. Milošević, Milan S. Milošević
Faculty of Electronic Engineering, University of Niš, Yugoslavia
Abstract. Some of advantages and disadvantages of active and passive
noise control in rooms at low frequencies are considered in this paper.
Examples described in the paper stand for the modal analysis of sound field
being used to reduce SPL in some areas of the room employing secondary
sound source - active control, as well as the analysis of SPL reduction
in the same room having absorbing ceiling - passive control. The main purpose
of this paper is to give information about some practical applications
of active and passive control of sound field in a room, and to show advantages
of detailed modal analysis that can be done using computer software. Computers
are now powerful enough for solving partial differential equations that
are needed for sound pressure field computation. Such software provides
an efficient tool to analyze sound pressure level in a room, especially
at low frequencies where statistical considerations are not convenient.
SMANJENJE BUKE U PROSTORIJAMA POMOĆU AKTIVNE
I PASIVNE KONTROLE NA OSNOVU MODALNE ANALIZE
U ovom radu su izložene neke prednosti i nedostaci aktivne i pasivne kontrole
buke u prostorijama na niskim frekvencijama. Primeri opisani u radu odnose
se na analizu zvučnog polja na osnovu modalne analize u clju smanjenja
nivoa zvuka u pojedinim oblastima prostorije pomoću postavljanja sekundarnog
izvora - aktivna kontrola, kao i analiza smanjenja nivoa istog zvuka u
istoj prostoriji, ali sa apsorbujućom tavanicom - pasivna kontrola. Osnovna
svrha ovog rada je da pruži informaciju o nekim praktičnim aplikacijama
aktivne i pasivne kontrole zvučnog polja, sa posebnim osvrtom na prednosti
detaljne modalne analize koju danas omogućuju računari uz pomoć softvera
za analizu zvučnog polja.
