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Soundstage and IEM Theory

post #1 of 26
Thread Starter 
*Disclaimer: all of the theories stated below have developed through research (to some extent) and perception (subjective view)
Therefore in no way, I am trying to publish a finished idea, however I am trying to reach a conclusion on this particular subject.

Small introduction:

I am currently studying at a school in England for an IB diploma. Throughout the last year, I have become aware of the emotion&perception related to music. One song sounding good on a particular day on the same equipment sounds better another etc. At first I was trying to find the best budget vs. performance ratio, but soon gave up. My taste in music gives me a good reference to how gears compare to each other and one particular IEM stood out: Sennheiser's IE8.
It completely immersed me and I have been enjoying it ever since. From that day on I tried to find out what was so special about the design and it's impact on the sonic signature.
It has been noted that the IE8's soundstage is one of the largest and I have found that the imaging is also very precise & very 3D like.
However it was not until I found out about wave deffraction in Physics, when I had a small breakthrough with my theory about the soundstage.

Main part:

The IE8 is distinctly designed with two major features often not found in other IEMs: the Bass knob and the very large design.
The bass knob acts as a vent for the rather large driver, the more air is let inside, the greater the bass is tuned up. This feature impacts isolation, still the whole sound becomes very "full", which, in my view makes it more of an extra, than a drawback.
The other feature is the design. And this might also give you some insight on why it's soundstage might be perceived as being so large.
The tube between the driver, has a certain diameter, diffracting the sound pressure waves and spreading out the energy. Therefore the over-all sound is perceived as being "wider", without a loss in energy. A very basic diagram shows my theory: https://apwiki.wdfiles.com/local--fi...iffraction.gif

Now I would like to address a view questions at the community: Am I completely wrong or could there be some form of truth behind this idea?

I will be updating this thread, if I gain more insight, but for now: Happy listening
post #2 of 26
This is the first post I've read that used science to make conclusions about the IE8's soundstage. Interesting theory. I wonder who designed the IE8 in the first place and what they would say about this matter. I find the IE8 to completely immerse me in the music as well and that is why I listen to them most of the time.
post #3 of 26
I don't have too much time to explain further, but if I am not wrong, the way IEMs and headphones create soundstage depends on how the sound wave is reflected inside our ear canals, as well as the lapse time between one wave of certain frequency and the next one coming after it.

You might want to search somewhere over the internet (other than wikipedia, just to have more info), on how sound waves propagate through our ear canals.

Edit: Hope this helps a bit more in your "research"
post #4 of 26
Back when I went to school I learned we use our entire ear for hearing, not just the ear canals passage to the inner ear... this also includes skin and bone around the ear. So this immense 'soundstage' from the IE8 has to be virtual/faked somewhat so perhaps your theory is close to what I'm guessing the manufacturers accidentally stumbled upon with the IE8... either that or they designed it purposely and there marketing stinks.
post #5 of 26
With all the iems I have ever tried, soundstage has been directly related to the nozzle inner diameter. The smaller the nozzle, the smaller the soundstage. I believe this goes along with your theory.

Despite these two iems obvious differences, I think this is exactly why the er6i soundstage is so small compared to the RE0. One is BA and the other Dynamic but I think the theory makes sense.

Another element is the distance of the tip insertion and the distance from the driver to your eardrum.
post #6 of 26
Without further research I'd hazard a guess that it is related to nozzle size but I don't think it's diffraction because the order of wavelength for diffraction to be strong would be rather high frequency, plus you have interference patterns and phase differences going on with the sound and I'm not sure what that would do to sound in such a small cavity.
Nice thinking though.
post #7 of 26
Mmmmm , the Klipsch Custom 1 has a much smaller soundstage than the Klipsch S2 but the nozzel diameter is the same.
In the S2 i think the driver is further away from the nozzel than on the custom 1 though so maybe that would contribute to the effect.
I am very interested in this as well.
post #8 of 26
The quality of the recording is paramount to this as well , most modern recordings are so badly compressed that there is frankly no distance between the instruments making effective soundstage creation difficult.
I have a few recordings that i use that have a great soundstage inherent in the recording, golden years by Bowie is a good one and The Raconteurs second album is also quality.
post #9 of 26
Thread Starter 
Yes, the quality of the recording is essential in order to maximise the potential of the IEM Soundstage, however the difference in the presentation of these IEMs is evidently noticeable and therefore is not all recording (if you know what I mean)

More research has shown, that there could be three things happening within the IE8s body: diffraction, reflection and refraction of sound waves. All of which contribute to the overall presentation.

We also have to encounter for the angle of the driver&nozzle. However as Daniel quite rightly pointed out, the diffraction will most likely occur in higher frequencies (above 10khz)... I just have to think
post #10 of 26
i agree with Daniel also u don't want reflection to occur.. otherwise residue noise would affect the sound... and they're really hard to control...
refraction? that implies the density of air/ear canal inside the IE8 changes? i doubt you would want diffraction, reflection or refraction to distort the sound... they are too dependent on your ear canal shape, the moisture level...
the open air system would do the opposite of what you suggest and reduce refraction?
post #11 of 26
HAHAHA thats too funny I am a ib diploma student in ny
post #12 of 26
Refraction of the sound waves would only be caused by a pressure change between your ear drum and the driver.
post #13 of 26
Quote:
Originally Posted by Graphicism View Post
Back when I went to school I learned we use our entire ear for hearing, not just the ear canals passage to the inner ear... this also includes skin and bone around the ear. So this immense 'soundstage' from the IE8 has to be virtual/faked somewhat so perhaps your theory is close to what I'm guessing the manufacturers accidentally stumbled upon with the IE8... either that or they designed it purposely and there marketing stinks.
I think soundstage has more to do with reflections of sound in a room (such as a recording studio) relative to the 'fundamental noise' than hearing with your whole ear, which I think functions more for the purpose of balance and actually funneling the sound into the ear. Which is why it is conceivable that headphones still have a "soundstage", but why its smaller than speakers (less distance to the ear, less time to reflect, smaller space etc).
post #14 of 26
Thread Starter 
Quote:
Originally Posted by hockeyb213 View Post
HAHAHA thats too funny I am a ib diploma student in ny
dude i really don't enjoy the I.B.
post #15 of 26
Quote:
Originally Posted by sebhuber View Post
*Disclaimer: all of the theories stated below have developed through research (to some extent) and perception (subjective view)
Therefore in no way, I am trying to publish a finished idea, however I am trying to reach a conclusion on this particular subject.

Small introduction:

I am currently studying at a school in England for an IB diploma. Throughout the last year, I have become aware of the emotion&perception related to music.
Emotion and sense perception eh? Quite the TOK disciple you are :P. This could be an interesting EE if you can figure out how to qualitatively measure something as subjective as soundstage as well as how to adjust nozzle diameter.

But again, idk how much diffraction there will truly be. I would've thought a small diameter would do the trick as sounds would be forced to ricochet off the ear canal more than with the IE8 (from which the sound can leave in a more linear fashion owing to the larger diameter).

Personally, I thought the soundstage had something to do with the resonance within the IE8s bulky chamber itself.
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