Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/17/84; site opus.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!hao!nbires!opus!rcd From: rcd@opus.UUCP (Dick Dunn) Newsgroups: net.audio Subject: subwoofers (small-driver magic?) Message-ID: <176@opus.UUCP> Date: Wed, 30-Oct-85 01:40:59 EST Article-I.D.: opus.176 Posted: Wed Oct 30 01:40:59 1985 Date-Received: Fri, 1-Nov-85 03:08:37 EST References: <808@psivax.UUCP> Distribution: na Organization: NBI,Inc, Boulder CO Lines: 32 > >Before everyone runs off and builds subwoofers with two 8" drivers, > >I'd like to point out that this isn't going to be much of a subwoofer. > > Ahem...the audio-pro B2-50 subwoofer uses (2) 5-1/4" drivers and I > believe it is fairly flat down to 20Hz. > > A friend of mine designed a subwoofer based on the audio-pro idea. He used > 2-6" phillips drivers in acoustically isolated, ported, cabinets... Could someone explain what sort of magic is used to make this work? I assume that if these small subwoofers are not only flat down to the bottom end of the spectrum but can actually produce reasonable sound levels down there, there's some form of mechanical transformer effect due to enclosure and/or placement. Reason: If you've got tiny little speakers like those mentioned and they're just flapping around in the open air, you end up having to move the cone an inch or two to slosh enough air around to make any usable noise. Even if you could get that much cone travel, you'd manage to have some interesting distortion problems. You can presumably get around the problem by something with enclosure and/or driver placement which presents enough load on the driver to reduce cone travel--trading volume of air moved at the driver for pressure. SO, could someone who knows explain how they work? Oh, while I'm at it, could two or three people who know nothing about the matter flame me after reading only half of my question, or agree with me completely and flame the people who think small-driver subwoofers can work? (No, I really don't WANT this--but you can sometimes get what you ask for by asking for what you know you're going to get.:-):-) -- Dick Dunn {hao,ucbvax,allegra}!nbires!rcd (303)444-5710 x3086 ...At last it's the real thing...or close enough to pretend.