[Bossatiger]

A simple question that has me somewhat puzzled.
I somewhat understand how soundstage works in headphones. Big factors include the angle and distance between the driver and the ear can make the headphone sound intimate (hd25) or immersive and deep (hd800). But when this distance/angle factor is gone and sound waves come so close in the canal, what makes some IEMs have a larger or smaller soundstage than others? How much does basic frequency response play from here? What about open back IEMs?

A broad question, I know, but I would love to learn a little about IEMs. I don't know much about the technicalities of headphones in general

 

[audionewbi]

This is a hard question to ask but for me personally it is how the sound is reflected on your inner ear. Some company spends a tonne of money research on how to position their nozzle just so that the sound reflects from particular part of your ear onto another part. Some companies invest a lot on the nozzle shape (for example Audio technica using cone shape nozzle whereas fitear using titanium tip).
 
Ofcourse drivers matter but based on experience the nozzle angel is the key.