Art: Why mention frequency response differences of the Shure and Etymotic while ignoring insignificant harmonic distortion differnces?
Because harmonic distortion is not easily recognized as a problem in listening whereas frequency response differences are.
I remember, many years ago, an experiment asssessing harmonic distortion. People could not tell the difference between 1 % harmonic distortion and .001 % - a thousand percent more of harmonic distortion was not noticed in listening.
Intermodulation (IM) distortion is another story. Many recordings show IM distortion from phase distortion from reflected sounds in the recording hall/studio. When a tone is delayed less than 5 milliseconds relative to the original tone, phase distortion is a real audible problem. This is why headphones are less articulate (have less focused imaging) than canal phones, and why room speakers are less articlulate than either.
Mr Iriver: Harmonic distortion at such levels should be very noticeable.
Art: Not at all. You could not hear the difference in harmonic distortion betwen the Shure and Etymotic. You do hear the frequncy response differences.
Mr Iriver: It should be remembered that real instruments bounce all over the place, which should make speakers and headphones more accurate. Also better imaging does not equal does not equate to more accurate. Accurate imaging should be as good as that of the recording, and IMO the etymotics lack of decay could be the something to make the etymotics sound with a better image. Also as far as imaging there are full size headphones that can beat canalphones in imaging, and adding soundstage only makes the sound much more lifelike.
Art: Now you are talking about phase distortion in the listening environment.
Once again: Recodring engineers go to special pains to control sound reflections in the live music environment. Reflections with a delay over 15 milliseconds add a pleasing echo that lends hall ambience to the recoded sound. Reflections with a delay under 10 seconds are bad - cause sibbilance and IM distortion, and smear/muddy the tone image, with a decay that is distortion not ambience. Speakers and headphones have this later bad decay with midrange congestion and IM distortion with poor (spread-out or blurring) imaging of a tone - canal phones do not have this and are more detail articulating.
Plus the phase distortion of speakers and headphones can compound the problem over that in the recoding room of live recording - changing a nice recorded ambience to IM distortion in the listening environment.
Headphone designers try to control for reflections in the outer and middle ear, making use of it to enhance bass and expand the soundstage. They accomplish this at the cost of blurred images and IM distortion.
Just because sound reflects in the live music room does not make this good. If you have a bad seat it can sound bad. Reflected sound in the listening room can make your speakers sound terrible if you don't place them carefully.
The best sound from speakers, as far as image focus, clarity of inner detail, and lack of IM distortion from phase delay sources (reflected spound), is in an open field of grass, with satelitte monitors 4 feet of off the grass and 6 feet from your ears and 8 feet apart, and a huge subwoofer to compensate for loss of bass by the absence of room reflections. This would give you the best of speakers and the best of headphone clarity and detail, with good image resolution.
Try this at home: position your speakers 3 feet from your ears (tweeters aimed at your ears) and 3 1/2 feet apart, and with the speakers at least 6 feet from the nearest wall. You will be amazed at the headphone like clarity.
