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I seem to recall it was a parcel shelf, though anyone daft enough to put parcels on it was asking for trouble. This was a time when seat backs stopped at shoulder level (and no seat belts in the back (UK)). The number of injuries from rear seat passengers and parcels striking the driver was quite high as I remember.
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I guess largely correct. The sound of sub-woofers designed to have the cone pointed downwards towards the floor can be affected as the space between the floor and cone acts like a short transmission line or have some other kind of acoustic effect.
Please correct if I am totally wrong in my assumption.
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BarryPearlman wrote: if I play Michael Jackson's "Billy Jean" and stand next to the speaker, my pants legs move on the downbeat.
That is a mental picture I really didn't need. 
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You aren't grasping straws[^].
A "up" mounted subwoofer will not only have the rest position moved downward, also, the suspension - basically rubber and resined paper - will "learn" the new position, so that bringing it into "front" position will take while to forget this.
In principle, this shift can be a major source of additional distortion.
Wether this matters dependes on the particular sub woofer. Car aftermarked subwoofers are often built with a long "overhang coil" (the coil is longer than the magnetic gap), which means rest psoition doesn't matter much - but it takes more power and onset of distortion is more abrupt.
In a short coil configuration, a change in rest position is indeed a major thing (and it's indeed a major thing for us to be able to detect such a shift in a 200ms end of line test).
Even then, many "home entertainment" subwoofers are built to basically repoduce a single frequency to get good "whoomp". If you have a "whoomp" woofer with a decent crossover - i.e. the woofer doesn't "see" the higher frequencies - there's little that could be noticed. Good enough for hip hop, sucks for Bach.
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Ah peterchen. At last someone who agrees that sub woofers are dreadful for decent music. Whatever happened to the obsession for flat frequenct responses?
I may not last forever but the mess I leave behind certainly will.
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I may not last forever but the mess I leave behind certainly will.
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The position you suggest woould probably result in a weaker or thinner bass signal. The other issue with facing open faced speaker upward is that it will collect dust, that too will color the sound.
Everything you wanted to know (and more) about subwoofer placement by people who know what they're doing. Polk Audio[^]
It was broke, so I fixed it.
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Holy cow! That's a very "deep" article. I definitely fall into the "stick your sub in the corner, turn up all the knobs and have fun...If you have low tolerance for moving speakers and twiddling with your audio gear, quit reading now." category.
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles
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Subwoofers often have their speaker(s) on the side because that way they use the percieved least space.
They normally don't point upward because if you get dirt on the cones it will rattle in a very disturbing way.
Exceptions exist of course. Usually for design reasons, Scandyna BassStation[^] (the bongo drum) comes to mind.
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With everybody majoring on the speaker cone, can I ask about the electronics
I have seen subs with the amp in the back and if this is one of those then the heatsink will be on the floor and receive less cooling potentially leading to failure
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Does your woofer take in power? If Yes - You will inadvertently hurt the cooling of the Amps inside by altering the orientation. There may not be any problem in the short term but it will surely reduce the life of the electronics inside.
From an electronics engineer 
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I've read somewhere that human ears can pinpoint direction of sounds only above certain frequency, so just considering the sound it shouldn't matter.
However this is the first time I have seen Samsung and audiophile in the same paragraph.
modified 20-Oct-19 21:02pm.
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I thought that I read somewhere that you need a mix of frequencies to determine direction.
It's the reason that emergency vehicles started mixing white noise into their sirens.
Single frequencies are hard to position because the the ear uses some kind of frequency attenuation profile to determine direction. I seem to remember that it also has something to do with our ear lobes and these effect that they have on frequency response so you can tell if something is in front or behind.
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I came to the conclusion a good while ago that advice from audiophiles or home theater enthusiasts (I count myself among these, even chased the THX dragon for a while) is largely religious in nature. After many years and much discovery I have come up with a solution that absolutely works for everyone. Throw away the science. A true audiophile will balk at this because no one wants to admit their time might have been wasted. We all have basically the same auditory senses in various states of disrepair. That's why this works for everyone and there is absolutely no argument against it: 1) position your speaker one way. 2) Listen. 3) Position it another way. 4) Listen. 5) Place the speaker in the position that sounded better. Repeat as necessary.
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Subwoofers, especially larger ones like 10", 12" or 15" produce waveforms that are long and not very directional. They also work better when they push "against" something that can transfer some of that kenetic energy.
In most home theater setups, if the sub-box is setup with a side firing cone, the best placement would be to position the sub so that the cone faces a wall in the room. There are some high end subs that have 2 side firing cones, and in those cases, they are positioned at a 90deg angle to each other and meant to be positioned in the corer of a room, with the cones facing the 2 adjoining walls. However Most subs that I've used/seen have down firing cones, which point toward the floor to help transfer and enhance the low frequencies they emit.
The reason this is the case, is that some of the lower freq. that subs give off (ie: <30Hz) are nearing sub-audible to the human ear, and are more transmissive frequencies, and having them transmit those lower freq. to the structure of the house helps you "feel" the bass, that your ear may not hear as well. Our brains are used to feeling lower freqs. as much as or more than hearing them.
I wouldn't point it up, you won't harm anything, but I think you will get less bass response from it in that orientation, as you would be minimizing the transmissive properties of the low freqs. Instead, rotate it to point down. You would probably have to put small feet on it, as you have to keep in mind that the cone can move as much as 2" of travel depending on the freq. and volume and cone design, so you don't want the speaker cone to be bottoming out hitting the floor. You need a gap to prevent this, which is why down firing subs have 1" or so high feet on them so they don't rest directly on the floor.
If it's a smaller sub, like a 6" or 8" cone, the frequencies produced are not as low, and these effects are lower.
-jason
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Directionality comes from how your ears interpret mainly two things: the loudness difference between the same sound in both ears, and the time difference between the same sound entering both ears. At low frequencies, where the distance between the ears is well below a half wavelength of the sound, the human auditory system uses primarily phase difference between sound received in both ears to tell direction.
Key to understanding all of this is knowing the wavelength of the sound. Roughly, it is 1000 feet / frequency. Example: 50 Hz has a 20 foot wavelength.
Below 200 Hz (5 foot wavelength), this no longer works effectively because the phase difference is too small to be detected, and below 80 Hz (12.5 foot wavelength) it doesn't work at all. This applies no matter if you're in a car, a room, or the Grand Canyon. See a simple explanation at http://en.wikipedia.org/wiki/Sound_localization
A 15" subwoofer and a 4" subwoofer both playing a 50 Hz sound will produce exactly the same wavelength sound, just to clarify.
A single high-frequency sound, say 1 kHz, will produce a complex interference pattern after bouncing off various objects on the path to the ears. This can cause both loudness and phase differences at the ears that are highly variable depending on exactly where the listener is. Try it sometime when you hear a high-pitched single frequency sound; move your head just a few inches and you will find the "source" of the sound coming from widely different directions. Ambulances using multiple frequencies reduces this (they will form more of an average) and adding white or other broad-spectrum noise will average sufficiently that the ears can correctly take the cue of loudness difference to locate the source.
A long-throw speaker is designed that way because it is likely a smaller driver and needs to move a greater distance to move the same volume of air as a larger driver. It has nothing to do with where it rests when placed vertically or horizontally. It is difficult to make long-throw speakers linear because it is difficult to make a uniform magnetic field with sufficient strength over the full range of movement.
The driver suspension (the "spring" force that keeps it centered) is far stronger than the weight of the cone. It is generally designed to have a certain spring force acting against the spring action of the air inside the enclosure. "Generally" because there are many options for designing drivers, enclosures, and alignments to achieve specific goals.
As one poster mentioned, all this is covered in Thiele/Small theory and parameters. Long/short throw, stiff/loose suspension, driver material and weight, magnet and gap size are all design parameters to achieve a certain set of tradeoffs that can be analyzed with Thiele/Small theory.
Placement of the subwoofer interacts with the room (walls, ceiling) to form interference patterns throughout the room. What matters primarily is the placement of the subwoofer (and how its sound is reflected/absorbed by the walls, floor and ceiling), and not so much which direction it is pointing. Yes, in some cases there can be additional loading factors; if pointed down and a small gap exists between floor and cabinet, it places an additional load on the speaker that it was not designed for and will change its frequency response. There may be vents that require some distance from a wall or floor for the same reason. But pointing to the side vs. up should make no difference.
Place a subwoofer in a corner and all its output reflects close to in phase with the primary wave at low frequencies. This will "sound" louder (in most reasonable cases) than putting a subwoofer in the middle of the room where its sound reflects from walls, floor, ceiling at widely different phases from the primary wave. This will probably "sound" less loud, but may sound "flatter". It's all dependent on specifics. Again, the way to look at it is by wavelength of the sound. At 30 Hz, wavelength is 33 feet, and it doesn't matter whether the sound came from the side or top or bottom, that's going to be a path length difference to your ears of maybe 2 feet. At 200 Hz (5-foot wavelength) that will make a big difference.
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In order of importance:
1) sub woofer frequencies are not directional and must move "air" in two directions - don't block either the direct or indirect air portals. 25 mm clearance from portal to a wall or floor is good, 50 mm better.
2) minimize any tendency to vibrate the case. This is best done by adding lots of weight as in adding a 50-100 mm cement skin which will translate to all power being used to move air, not shake the case. If your sub woofer sounds good at 20 lbs, I'll sound great at 200 lbs and over a much broader range of vol levels.
3) avoid setting sub woofers on carpet if an air portal is down-facing, but if necessary, raise the case bottom at least 25mm above the carpet surface with legs made of steel bolts sharpen to a point to penetrate the carpet and rest on the floor below. Use levelers where needed.
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Laying it on another side will not harm it, nor materially affect the sound.
The only thing that you might take into account is to mechanically isolate it from hard surfaces, using either stick-on rubber feet, or placing it on a sticky mat.
(It will vibrate itself from a piece of carpet or suchlike.)
You can even place it under a sofa or bed without detracting from the audio.
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A farmer accused of cattle rustling is the first American to receive prison sentence using predator drone assistance. Moo![^]
It was broke, so I fixed it.
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Nice writing, thanks for sharing.
It was broke, so I fixed it.
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Thanks. It's one of the first pieces I've written, and definitely needs a rewrite now that I have more experience. Still, I rather like the basic story idea.
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Interesting that he was found innocent of rustling, but was convicted and sentenced essentially for resisting the authorities.
If your actions inspire others to dream more, learn more, do more and become more, you are a leader.-John Q. Adams
You must accept one of two basic premises: Either we are alone in the universe, or we are not alone in the universe. And either way, the implications are staggering.-Wernher von Braun
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.-Albert Einstein
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And apparently, have been for a while[^], with newspaper headlines as far back as 1893 announcing this "new" fad among the genteel and educated classes.
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