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Giant Sub-Woofer
PuceBaboon sent us linkage to an amusing story about building a
gigantic custom sub woofer. I was about to yawn until I looked at the pictures of them excavating a 60 cubic meter hole, and laying bricks. This one might be a little outside the realm of reasonable, but it's damn impressive.
I've built my own speakers before, and while you can do a good-enough job without too much hassle, making a first-rate product is very labor and math intensive. If this guy is putting that much money and effort into this project, I really hope he gets all the damping and power equations right. Otherwise this will all just be a publicity stunt (maybe that's what it is anyway). I'm thinking about the amplifier he needs to run it right now. That's a lot of juice! And juice = money. And worste of all, you'd never be able to use the thing! Even a store bought stereo goes well above the municipal noice ordinances. And bass carries the furthest! What is this guy thinking?
If he ever does use it, I bet he'll feel that really cool thumping sensation in his chest though.
Slashdot Syndrome: the sudden, extreme urge to correct someone in order to validate one's self.
The question is, if he blows one, will anyone notice :)
Anyway if you had looked at the pictures, the speakers are easily accessed through a removable floor panel. Similar to the wiring in a server room.
Why is it that people look at a project, which someone else has put a ton of time and effort into, and think they can find flaws in less than a minute. Is your opinion of your fellow man that low, or your opinion of yourself that inflated?
I hate to nit-pick, but it's a large, elaborate enclosure and not a huge subwoofer itself. Slightly more practical is the "Cult of the Infinitely Baffled".
y .h tml
http://home.comcast.net/~ttriff//page2IB-Galler
It's a horn. A horn is an acoustic transformer, which matches the impedence of the cone to the impedence of the air, giving a very effecient energy transfer. That means very, very fast bass, with more attack than any brute force method you describe. Your speakers are the equivalent of hitting a feather (the light air) with a golf club (heavy cone). The feather won't go far as there's a big impedence mis-match. The horn gradually makes the air the cone is trying to move match with the weight of the cone, so to speak, like replacing the feather with a golf ball in the above analogy. When the cone moves the air now, it moves easily because of the matched impedence.
To give you an example, my small horn speakers with a 7.5 watt amp go as loud as my brother's PA speakers on his 750watt amp. Do the logarithms and that means that my speakers are 20db more sensitive than his - because of the horns! (actually about 6db of that is due to bigger magnets, but the rest of the increase is down to the horns)
So, the end result is many, many times superiour, with louder sound, with less distortion than your "box" speakers.
-- oldthinkers unbellyfeel ingsoc
Hi-fi audio is all about vibrating air to sound "like" a real performance. If all you think about is the electronics, you are forgetting about the physical properties of the chosen speaker, the way the cabinet affects those properties, the accoustics of room, the precision of human hearing, and the subjective perception of the listener. Audio design is a discipline which demands that one think about not only electronics (although electronics are important), but wave physics, biology, and psychology.