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Music Media Toys Technology

Do the 5.1 Stereo Headphones Really Work? 84

Tamor asks: "Zalman, the company behind some extremely high quality PC noise-reducing products are now selling real 5.1 surround sound headphones. The surround effect is achieved by placing 3 drivers in each ear-piece. As a geek-with-young-family this product's pushing all the right buttons for me, it looks cool, and means I can finally achieve surround sound without waking the kids. Or does it? I was sure that to place a sound spatially your brain relies on the delay between hearing the sound in one ear and then the other. If your left ear only hears the left 3 channels, and your right ear only hears the right 3 channels isn't this making it more difficult for spatial placement to happen? Do you know if/how these are achieving surround effect if each ear is only hearing half of the audio field?"
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Do the 5.1 Stereo Headphones Really Work?

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  • by wolf- ( 54587 ) on Monday January 26, 2004 @04:24PM (#8091927) Homepage
    I'm missing something with this category.
    Why not call the manufacturer and ask them how they do it? Maybe get a set from them to demo and test. See if YOU can hear the difference.

  • Physics Problem (Score:3, Informative)

    by WyerByter ( 727074 ) on Monday January 26, 2004 @04:29PM (#8091994) Journal
    To my understanding, your ear places sounds spatially by volume. It sounds louder in the closer ear.

    Beyond that, unless you have a really big head, the difference in arrival time to each ear is less than a microsecond. That is surely too small for your brain to comprehend.
    • Volume a large factor of course, but it's extremely complex. All sorts of things like high-frequency "presence" and attack speeds, etc. all affect where your brain places sounds in the spatial field. You can get "surround sound" effects with regular stereo headphones and regular stereo recordings too. A lot of ambient artists try to play with creating surround sound in stereo. And of course, any good engineer will talk about where things go in "the field", and they are referring to more than simple panni
    • Re:Physics Problem (Score:4, Interesting)

      by pbox ( 146337 ) on Monday January 26, 2004 @04:42PM (#8092134) Homepage Journal
      Beyond that, unless you have a really big head, the difference in arrival time to each ear is less than a microsecond. That is surely too small for your brain to comprehend.

      No it is not. Strange but true. You can always tell the direction (not just left-right but any degree in 3 dimension) where sounds come from (true only for tone above 100Hz or so). Therefore your ears/brain can somehow decipher the minite differences in sounds arriving to your ears.

      However, back to the topic. You have 2 ears, therefore 2 speakers are enough to create a complete 3D soundscape. The 5.1 headphones are pure gimmick. You are better off spending some money on a decent pair of 2 speaker headphones, like AKG/Grado and my personal favorite, Sennheiser. If you like music, you are much better off spending $500 on a pair of headphones, than spending the same on 5.1 speakers.

      There are some (classical) recordings out there that are done using a fake head, with mic in place of the eardrums. When using in-ear-canal headphones (think Shure / ER) you are placed in the sound environment exactly like where that head was. I belive it is called aural recording, but please post reply if you have correct info.

      BTW, comp buffs, EAX by Creative is a model, which creates the 3D sound enviroment. It is a model on how our ears work and you can think of it as a 3D modeling, where you specify the 3D coordinates and the enclosing space (and types of walls), and the system outputs a L/R (or 5.1) signal which tries (with various degree of success) to place it in the right spot.
      • Re:Physics Problem (Score:3, Informative)

        by Jerf ( 17166 )
        However, back to the topic. You have 2 ears, therefore 2 speakers are enough to create a complete 3D soundscape. The 5.1 headphones are pure gimmick.

        The 5.1 headphones would be pure gimmick, if we had been able to work out the sound transformations for convincing the brain a sound is coming from a given direction.

        AFAIK, there has been progress in the field but it has hit a wall, and all the demos I've ever heard impart a very synthetic characteristic to the sound vs. the original source. (And I'm not sp
        • Re:Physics Problem (Score:4, Informative)

          by pbox ( 146337 ) on Monday January 26, 2004 @05:06PM (#8092404) Homepage Journal
          Now, I've never used these or even heard of these, but I can easily believe that they are more then a gimmick at our current levels of understanding of sound spatialization. Nor would I expect two-speaker setups (headphones or otherwise) to match these any time in the forseeable future.

          I agree.

          So to summarize all this:

          1. If the recording is mode with the fake-head, it is best to use 2.0 headphones / in-ear-canal or otherwise.
          2. Rest of stereo audio sources are best with a 2.0 headphones
          3. Computer generated sounds (especially FPS) best with 5.1 headphones (no or less calc involved)
          4. DVD-Audio, SACD 5.1 sources are best with 5.1 headphones, IF are not remastered from a stereo source, but rather are recorded with 5 mono microphones.

          Does anyone can improve / extend on above, please post.
          • Sounds good.

            So this is more then just a graceful "I'm not trying to be antagonistic" post ;-), I'd point out to people that really good 2.0 headphones are actually pretty easy to come by if you can get earbuds. As I write I'm listening to a Mozart clarinet concerto through my Sony MDR-W08 headphones [], which are dirt-cheap as headphones come but nearly match the quality of my $100 studio-style headphones I bought for my synthesizor-based music composition. I don't know that you can get MDR-W08s right now (do
      • Re:Physics Problem (Score:2, Informative)

        by Reducer2001 ( 197985 )
        Nice info in parent post. The recording technique is called binaural [] recording.
      • Well, if you're an audiophile looking for the best headphones out there, the 5.1 are definitely not it. However, if you want them to play games or watch movies with 5.1 sound, they're definitely preferable. My friend has a pair, everyone thinks he cheats now :)
      • I have noticed an audio phenomenon with a music synthesizer where a mono signal (both left and right channels of a headphone set receiving exactly the same signal) will produce a sound that travels from one ear to the other and back for about two seconds.

        This happens only on one patch created at random with a Yamaha FM synthesizer TX-81Z model.

        I have no idea as to how it happens except to guess that a certain combination of the phases of the different original operators is causing a 'trick of the ear
    • Re:Physics Problem (Score:5, Interesting)

      by Otter ( 3800 ) on Monday January 26, 2004 @04:46PM (#8092175) Journal
      There was a famous neuroethology experiment with barn owls. They have asymmetrical ruffs on their ears, one pointing up and one down. Sounds have a different volume in each ear depending on the altitude of the source.

      But, it was also showed (by putting headphones on them, playing a mouse sound and watching how their heads moved) that they use volume to determine altitude and time offset to determine bearing. So it's definitely possible -- although I have no idea what system human perception uses for the same problem.

      • But, it was also showed (by putting headphones on them, playing a mouse sound and watching how their heads moved)

        Ok, so where's the obligatory link to the owl with the headphones?
    • Re:Physics Problem (Score:4, Insightful)

      by mleczko ( 628758 ) on Monday January 26, 2004 @05:44PM (#8092869)
      Well, actually, you only need two channels for surround sound. There are quite a few factors to define where a sound source is located. As far as the horizontal plane is concerned, the location is determined by two factors. First the time difference between the arrival at the ears is taken into account (makes for a astonishigly small time scale, especially with higher frequencies, but the brain can handle it). Then, the volume difference is evaluated: If a sound source is to your left, the signal is louder in your left ear then in your right. As far as vertical position is concerned, the form of your outer ear is relevant. Dependent on the position of the sound source, different frequency bands are attenuated or amplified. These are the so called HRTFs (Head Related Transfer Functions). Using this information, you can filter your sound sources with the according transfer functions and get a really realistic result. I once was able to try out such a system as part of a course here at university. It simulated 5 sound sources in a room and there was a head-tracker mounted on the headphones. So if you turned your head left, the drums would become louder. Pretty cool stuff! :-)
    • Beyond that, unless you have a really big head, the difference in arrival time to each ear is less than a microsecond. That is surely too small for your brain to comprehend.

      That's assuming that the brain measures the timing delays.

      I recall reading somewhere - I forget where - that the shape of the cochlea helps determine frequency. Higher frequencies tickle the hairs further along the cochlea.

      I could easily see similar tricks being done "in hardware" to get accurate measures of timing delays rath

  • by forsetti ( 158019 ) on Monday January 26, 2004 @04:33PM (#8092036)
    The Headphones are "smart" enough to create an appropriate delay, per channel, to cause that spatial effect you refer to.
  • google? (Score:5, Informative)

    by iamjim ( 313916 ) on Monday January 26, 2004 @04:33PM (#8092040)
    reviews found at: [], [], [], [], Tom's Hardware [], [], etc...
  • by phoenix_rizzen ( 256998 ) on Monday January 26, 2004 @04:35PM (#8092060)
    This month's CPU magazine has a review of these headphones. Don't recall the specifics, but they received a good review. The reviewer found them to be much better than stereo headphones during gaming sessions as you could hear sounds from all directions. But the sound quality for DVD movie playback wasn't so hot.

    There might be a copy of the review on their website (no I don't have a URL, use a search engine).
    • I notice that the reviews tend to say that the sound was interesting in its effects, but not very high quality for things like movies and music.

      Anyone else doing something similar, but with high quality sound, or is this too new? (Sorry, I'm not an audiophile, so I have no idea.)

  • It probably places sound in the same way those false surround sound systems place sound, by mimicking the left channel in the right ear and vice-versa, but at a different volume level. Distance can easily be faked with volume.

    I don't imagine this is overly difficult, provided there are at least two speakers in each headphone. I'm interested, for sure!
  • a friend has these (Score:3, Interesting)

    by gyratedotorg ( 545872 ) on Monday January 26, 2004 @04:40PM (#8092110) Homepage
    a friend of mine has these. i havent tried them yet, but he's been raving about them.
  • Not to be snarky: (Score:5, Informative)

    by attaboy ( 689931 ) on Monday January 26, 2004 @04:42PM (#8092139)

    But the Zalman product page that you linked to in your post had links to several online reviews. Were those insufficient? I found them to give me all the information that I would need to make a $40 purchase... [] [] [] [] [] []

  • Two Ears (Score:3, Funny)

    by sabNetwork ( 416076 ) on Monday January 26, 2004 @04:42PM (#8092141)
    Where did you find those other three ears? Please, I'd love to find out.

    It's a gimmick, christ. You only have two ears; it doesn't matter where the sound is coming from. Direction is simulated by the recording, not the headphones.

    • I know some people aren't into the multichannel recording thing but just to amplify: 5.1 channel audio recordings are available, even for those of you who have nothing more than a decent component CD player.

      So go find yourself a DTS CD (you'll need a digital output to something with a DTS decoder, but that's still not really a big deal), or a multichannel SACD or DVDAudio, and its plain-old stereo CD equivalent.

      For an example, Telarc's recent issue "Rainbow Body". Available on Audio CD and on SACD (note:
    • IANAAP (Audio Phile)

      It seems to me that there is more than what you HEAR that determines direction. I wonder if your body can sense the sound waves to help determine direction.

      If what you say is true, then how do you determine if a sound is coming from in front or behind you? If the direction-dtermination is based on the time difference between the 2 ears, there are an infinite number of points that represent the true source of the sound, represented by a circle.

      If this is hard to understand in words, im
  • Sony alternative (Score:3, Interesting)

    by HeroicAutobot ( 171588 ) * on Monday January 26, 2004 @04:47PM (#8092188) Homepage
    Sony also has the much more expensive MDR-DS5100 [] and the still even more expensive MDR-DS8000 [].

    I've been very tempted by these, but haven't been able to find many reviews. (I haven't looked for a few months though. Maybe there's more information available now.)

  • You know what? (Score:5, Insightful)

    by Lord Bitman ( 95493 ) on Monday January 26, 2004 @04:48PM (#8092197) Homepage
    These guys who make the headphones, they sort of do this for a living, so they probably know more about it than you. That is: Anything you can come up with in the first five minutes after hearing about the idea, they rely on already having come up with.
    This isnt something that somebody decided one weekend would be neat, and so slapped three headphones together with duct-tape and started talking to magazines. They developed, designed, tested, talked to various manufacturers, looked into methods of distribution. Do you think that in all that time, nobody would have considered how surround sound would be best implimented in a pair of headphones?

    Editors need to stop accepting stories with these bullshits tacked on. If you want to make a completely uninformed comment, post a comment after[if] the article is accepted.
    • Where as part of the question was if, the other part of the question was how. And that answer the engineers don't usually put on their websites, because the marketing guys don't let them anywhere near it.

      And if you think that HOW is a BS question, why are you here?
      • I'm not saying the question has no merit whatsoever, but too many articles are of the form:
        [News Item/Question] [Completely Fucking Stupid Comment/Extra Question which has been "tacked on" and has no redeeming value whatsoever]

        They're editors. Would it kill them to edit every now and then?
    • Re:You know what? (Score:4, Insightful)

      by Elwood P Dowd ( 16933 ) <> on Monday January 26, 2004 @06:12PM (#8093211) Journal
      Ah, yes, the engineers may have thought about it, decided that it would be too expensive to implement, and then done something that doesn't work well but only costs $40 rather than $600 for the competing Sony product.

      So, marketting or otherwise, his question is worthwhile. His question can be answered by a myriad of reviews available on the subject, but that's not what you seem to be talking about.
  • Easy (Score:3, Insightful)

    by wishus ( 174405 ) * on Monday January 26, 2004 @04:48PM (#8092198) Journal
    Just because the right can is on your right ear doesn't mean it can't play something from a left channel. There are three drivers in each can, remember? Even if there weren't, you could still mix the left channel into the right can at the appropriate delay and volume.
  • by esm ( 54188 ) * on Monday January 26, 2004 @04:51PM (#8092236) Homepage
    Sorry, I have no experience with these headphones. But: about 10 years ago, I volunteered as a test subject for some experiments done at NASA Ames (Mountain View, CA, USA). One of them was for a device called the Convolvotron []. It's a thingy (sorry for the technical term) which takes multiple sound sources and "localizes" each one so it sounds like it's coming from a different place. It worked incredibly well with only two speakers. The big problem was distinguishing between straight-in-front and straight-behind. With headphones and human ears, I suspect that's just a darn difficult problem. But side-front, side, and side-rear were very easy to differentiate.

    Although the tests took place in a sound chamber, they were kind enough to give me a demo tape -- and this tape is amazing. They demo about 5 different voices (simultaneous ATC conversations), both flat and spatialized. Flat, it's impossible to differentiate them. With the convolvotron, it was possible and easy to track each conversation separately. Each one sounded like it came from a different place.

    This was early 90s. Processing power has certainly increased since then. It should be possible, and relatively cheap, for someone to use Convolvotron-like technology to convert a 5.1-channel signal to spatialized L-and-R ones for use with regular headphones. There shouldn't be a need for special headphones.

    Lots of Google hits [] for "Convolvotron". Enjoy.

    • I have no idea if it uses similar technology, but I find the Dolby Headphone technology found in some dvd players (WinDVD and PowerDVD for Windows most notably) works to similar effect.
    • Two things would interest me greatly. One, to hear those tapes. Two, I wonder what effect various types of lossy audio compression would have on the effect.
    • Actually, the straight in front and straight behind thing is related more to the human ear/brain/central sound processing unit/whatever. If a sound takes exactly or almost exactly the same amount of time to travel to both ears, there's no way for the brain to determine a direction without echoes or reverberation or something.

      If you close your eyes and have someone snap their fingers directly behind or directly above your head, you probably will not be able to determine quite where it's coming from.


  • cues (Score:5, Interesting)

    by ballpoint ( 192660 ) on Monday January 26, 2004 @04:53PM (#8092254)
    Left-right stereo has been here a long time and it works wonders with headphones. No doubt about that.

    And since any sound arrives at your two cochleas, it must be possible to simulate any sound position just by exciting your two ears, preferably with in-ear phones.

    But I have a hinch that cues about whether a sound is at the back or front come subconsciously from:

    1. Turning your head and registering the changes in sound.
    2. Echoes and reverb. This only works if you know and 'feel' the room. (*)
    3. Changes in frequency response due to the structure of your ears. This only works for sounds you know.

    As the headphones are fixed to your head the first, and probably the most important, cue disappears. The room where the sounds were recorded does not match the room you're in, so the second cue disappears. And finally you will be listening to new, unknown sounds. There goes the third cue as well.

    But in true /. fashion, I'm posting this without actually having experienced 5.1 headphones with more than one speaker on each side. I'd like to try though.

    (*) While I'm listening with isolating in-ear buds, it is strange that the sound changes dramatically the moment I enter a building from the outside. Hard to explain by reverb and echo as there is little sound leakage from the buds to the outside and vice-versa.
  • Hearing (Score:3, Interesting)

    by DarkDust ( 239124 ) <> on Monday January 26, 2004 @04:53PM (#8092260) Homepage

    I was sure that to place a sound spatially your brain relies on the delay between hearing the sound in one ear and then the other.

    Yes, this information is used for left/right locating. But AFAIK (IANAES, I am not an ear specialist) also interference caused by sonic reflections from your shoulders are needed for locating whether a sound comes from above or below. I don't know how the distinguishes front/rear locating, though.

  • by dk.r*nger ( 460754 ) on Monday January 26, 2004 @04:55PM (#8092285)
    I tried a pair of Sennheiser headphones some five or six years ago.

    I believe they cost about $600 or even more, and they had really great sound. I don't have much experience in headphones, so I'm not sure if this basically would apply to any $200+ set... ?

    Anyway, they lacked one big thing: The subwoofer. Half the surround experience is the feeling of the ultra low frequency in your stomach, and earphones just wont do that.
  • by TrebleJunkie ( 208060 ) <ezahurak@at l a n> on Monday January 26, 2004 @05:01PM (#8092346) Homepage Journal
    Many many moons ago, when I was doing video production work, I received a sample CD from an audio library collection billed as "3D-sound".

    I don't know how the stuff was recorded, but it was recorded such that you really could localize the sound, in space, in 3 dimensions, from regular ol' stereo headphones. The most memorable tracks on the CD was of someone getting a haircut. You could hear *where* the scissors "were" around your head. You could tell where the hairdryer was blowing. Not just left-or-right, but *around* your head. The stuff was amazing.

    I'm guessing that not just volume and left-or-right determines where you hear things, but phase as well.

    But, anyhoo, the point being that you can very likely achieve good surround-sound sounding stuff with just one speaker per ear, and not three.
    • this kind of effect has been around for quite some time (best known example is the beginning of the final cut album from pink floyd) (hint: google for holophonia or holophonics)

      iirc it's actually very simple, the sounds were recorded using a dummy head with two mikes where the ears would have been
  • by ewhenn ( 647989 ) on Monday January 26, 2004 @05:04PM (#8092385)
    In 5.1 the ".1" is a subwoofer. These headphones can't possibly be 5.1

  • No. (Score:3, Interesting)

    by 3-State Bit ( 225583 ) on Monday January 26, 2004 @05:15PM (#8092541)
    I was sure that to place a sound spatially your brain relies on the delay between hearing the sound in one ear and then the other.

    Knowing nothing about human hearing we can almost rule out this conjecture. Noise travels at about 761.207051 mph [] and your ears are about a foot apart.

    That means there is a difference of 895.706603 microseconds [] between when the first ear would hear the sound and when the second one would.

    This is 1/1116th [] of a second, meaning that if your brain 'ticks' subconsciously at anything less than 1100 hertz its timing would be too coarse to catch this minute difference.
    The brain, in fact, ticks [] a couple of orders of magnitude slower than this, and moreover the theoretical maximum a single neuron can tick is 2000 hertz [], so there would have to be ~0 ms delay in signal propagation between neurons, and the signals would have to make a straight line from each ear toward the area in which the signal is to be processed in order for comparison to occur together with pertinent timing information. (The brain, of course, is not so precisely wired that it could take into account some kind of fixed minute differences in timing among various input sources.)

    So we can rule that out. The next idea continues with your implicit assumption that each ear is, logically, a fixed point of input, with the brain reconstructing all spatial information. (Ears, in fact, have a complex set of ridges precisely because they do convey spatial information)

    But if we thought of ears as mere fixed points of frequency/amplitude sampling, we might be tempted to think that all spatial information is reconstructed from minute differences in amplitude -- the ear nearer the sound source would hear it more loudly. We can also eliminate this conjecture because the two spheres of possible sound location a given distance from each ear intersect not in one point but a whole arc of possible places. What I mean is, if all your brain knew is : "Ear 1 hears source at A loudness and ear 2 hears source at B loudness, and ear1 is at (x1, y1) and ear2 is at (x2, y2)", then, together with information about how sound loses amplitude with the square of the distance it travels and inversely with the frequency (assume the pertinent natural laws are hard-wired), it could produce the fact: A-ha! The source must be 10 feet from ear1 but 10.23 feet from ear2.

    The problem is, there is not ONE point that fits those descriptions, but an infinitely many.

    If your ears were just input points, then, if you start playing a sound file on the computer in front if you, it should sound the same with your eyes closed now as it would if you turned around and heard it from behind: Each ear hears an equally loud sound, only now from behind instead of in front. The problem is, you can tell that it's from behind and not from in front of you! (Try a double-blind test if you're not sure -- place one speaker dead in front of you and one speaker an equal distance dead behind you, write a script to randomly play either full left or full right balance, close your eyes and listen to the random tests; you'll always be able to tell where the sound source is coming from.).

    Okay, so now we've long-windedly debunked the naive assumptions about how the brain might reconstruct spatial information. How does it?

    Beats me.
    • Have you ever heard of an effect called interference? I allows you to detect changes in waves of wave length shorter than you can sample. And since most people have two ears, comparing the two inputs should be fairly simple for the brain.

      And also there is fact that the brain does not 'tic' not at all. At least on in the way a centralised von-Neumann architecture does. Don't quote findings on neural response, since they disallow for the fact that the nerve input may be parralised (ever count the nerve stran
    • Re:No. (Score:4, Insightful)

      by Anonymous Cow herd ( 2036 ) on Monday January 26, 2004 @06:15PM (#8093253) Homepage
      Your basic mistake is imagining that human sensory input is clock driven rather than signal driven. Your auditory cortex isn't out there "polling" your ears to see if you're hearing anything, rather, the sensors in the ear signal the cortex once a sound (input event) is detected. Also, while the number of points that match your two 'ear judged' distances are infinite (but for all practical purposes, it's finite, this is a variation on Xeno's paradox) your ears are directional, due to their shape (this is also how you can tell difference between sounds in front and behind)
    • Re:No. (Score:4, Informative)

      by Frans Faase ( 648933 ) on Tuesday January 27, 2004 @07:08AM (#8098239) Homepage
      This argument is completely of the mark. The brains does contain specialized areas for detecting the delay. For low tones the spikes produced by the detecting hair cell, match the wave front. These are than transported to an area in the brain where there is a line of cells where the signals from both ears are at opposite ends. The cells where the signals arrive at the same time (depending on the delay caused by the spike to travel through that cell in the line) produce the strongest response and determine the direction from which the sound originates.
  • I haven't heard about this product yet, but it's now on the list. I'm fascinated by stereo sound, as for the first 26 years of my life I've had only one ear. I just had the other operated on this past year and I'm starting to experience spatialization and stereo sound for the first time ever. It's easier with headphones because the vibration helps with the effect. Still have to crank the right channel a bit, tho'.
    • As a kid I had a "lazy" eye that didn't let me see in stereo for a while -- later than many kids have it.

      Once I finally determined to actually wear my patch, I remember realizing that I could see depth so much better afterward. At this moment I'm not taking that for granted.

  • Not quite the same thing, but has anyone had any experience with this []? Dolby says, "Best of all, it works with any stereo headphones", yet they claim it "isn't some kind of pseudo-surround effect: it's for real". Hmmm...
  • I'm sure many of these geeks here have used PowerDVD or WinDVD here. There has long been a technology to simulate Dolby 5.1 (YES! with the .1 even!) with 2 sided headphones. And that's the little Dolby Headphone thing in your PowerDVD settings. (I think somebody else has posted this URL too, but anyway...) More detailed description here The human ears takes a lot more cues than simple difference in amplitude and timing
  • by cr@ckwhore ( 165454 ) on Monday January 26, 2004 @11:53PM (#8096634) Homepage
    Personally, I'd wait until version 5.2 because we all know that .0 and .1 releases are unstable, and you certainly wouldn't want your ears falling off.

    -- disclaimer: This absolutely the most retarded post I've ever made.

  • I've worn hearing aids over the last 20 years or so, and I've come to the realization that sound and perception is a lot more than just what the ears hear. My hearing isn't that bad, but it's difficult to get along without them.

    The first thing you have to realize, is it isn't just what your ears hear, it's the vibrations that you feel all over your body that affect your spatial perception. Think about it, if spatial perception was just the difference in sound arrival time between each ear there should
  • by Tamor ( 604545 ) on Tuesday January 27, 2004 @02:56AM (#8097495)
    I found out the actual answer to my question, and no it isn't on Zalman's site or in the reviews, and yes I expect that they did think about this before putting a product out. The answer is that the pinna (the outer part of the ear) catches the sound and funnels it down to the ear-drum. The folds and curves of the pinna alter the waveform of the sound as its funneled, and this happens in different ways depending on the direction in which the sound enters the pinna. The brain picks up those differences and is able to tell whether a sound originated in front, behind, above, below etc. So that's how you're able to spatially place a sound you can only hear in one ear. Neat.
    • I forgot to add that it's the fact that everybody's outer ear has a uniquely different physical structure that apparently makes it so difficult to simulate surround sound in a way that works for everybody. Everybody's outer ear distorts the sound in a different way, so modulating the sound in a way that would make placement perfect for me wouldn't work for someone else at all.

      I can't decide whether in posting this question I've learned more about hearing or about the mentality of people who didn't see that
  • if you have 5.1 ears...

  • well, swayed by the hype and the claims, i picked up a pair of isound 5.1 home theatre headphones []. the deal sounded like a steal (around $40). well, packaging was sexy enough - the headphones come ensconed in velvet cloth, red ribbons, etc. you also get a mini-amplifier and all kinds of cables.
    what you don't get, however, is good sound quality! there is hardly any clarity to the sound, and it is nowhere close to the output of my regular headphones - a mid-priced sennheiser and a reference sony model.

The intelligence of any discussion diminishes with the square of the number of participants. -- Adam Walinsky