Porting, internal volume, and effects on bass and soundstage in a DD IEM?
Aug 8, 2015 at 12:39 PM Thread Starter Post #1 of 2


Mar 10, 2008
For a long time I've wondered what the effects are of increasing port size or adding a very small port (if sealed) to a hybrid or dynamic IEM.

I'm going to try it eventually but wouldn't mind some theory on the topic first. I figure ports can simply be closed again, so aside from visual concerns which don't bother me, it should be a reversible experiment. I've been intrigued by IEMs that claim to offer altered signatures via variable aperture porting.

I've also wondered about increased or decreased volume on the rear side of the driver and effects on sound signature, particularly bass amplitude and response speed. In this case it wouldn't be hard to decrease by adding something that reduces internal air volume, however perhaps a little harder to increase. Again I'm interested in some theory on what an increase and decrease would result in.

Also interested in practical results if anyone has experimented. Appreciate any thoughts.
Aug 9, 2015 at 1:18 PM Post #2 of 2
I'm a noob, but I remember this http://rinchoi.blogspot.fr/2012/10/ultimate-ears-part3-in-depth-analysis.html  that you might find interesting.

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