Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site opus.UUCP Path: utzoo!watmath!clyde!floyd!harpo!seismo!ut-sally!opus!rcd From: rcd@opus.UUCP Newsgroups: net.audio Subject: (more on passive speakers, etc.) Message-ID: <235@opus.UUCP> Date: Thu, 15-Mar-84 20:12:01 EST Article-I.D.: opus.235 Posted: Thu Mar 15 20:12:01 1984 Date-Received: Fri, 16-Mar-84 07:41:40 EST References: <1049@inmet.UUCP> Organization: NBI, Boulder Lines: 21 > > 2. Extra speaker in addition to the normal stereo pair... > This isn't quite as far-fetched as it sounds. THE AUDIO AMATEUR ran an > article a few years back entitled "The Not-Quite Passive Radiator". The > premise of this article (sorry, I no longer have it) was basically: When > using a conventional woofer as a passive radiator, an R-L-C network could > be attached to it to 'tune' its response by reinforcing the voice coil... This misses what people have been questioning. A passive radiator is built into the same cabinet as the active radiator it supports - and is typically not less than about 2/3 the area of the active radiator. By being in the same enclosure, the displacement of the passive radiator cone can be expected to be on the same order of magnitude as that of the active radiator - as compared to having a speaker "out in the room" where the phonon field is much diminished. Incidentally, the electrical tuning of the passive radiator is one way to twiddle (sorry about the technical term :-) its effect - it can also be tuned mechanically by placement, baffles, etc. -- Cerebus for Dictator! {hao,ucbvax,allegra}!nbires!rcd