[fourrobert13]

I just purchased some Dunu Titan 1 iem's and the package included s,m , and l ear tips.  I've found medium fits me best, but now which medium is best?  Some have larger diameters than others and then some are red/black in color.  I'm not sure what the differences are or if the diameter size impacts the sound.  I tried searching this, but didn't find anything specific to my questions.  I'm kind of new to this stuff.
 
Thanks

 

[cel4145]

Yes. IEMs come in different nozzle diameters, so tip opening diameter should match. As far as diameter of the tip itself, that's a comfort and sound quality choice. You have to just try them.

Since there is an active impressions thread for your IEMs, people there could probably suggest alternative tips if you need some: http://www.head-fi.org/t/744083/dunu-titan-1-titanium-coated-diaphragm-half-in-ear-earphones

 

[ProtegeManiac]

Not every Medium (or S, XS, L, etc) size tips are exactly the same across all brands, plus there's how pliant the material is, so while M is the general size some will seal better than others depending on your ears. 
 
As for the nozzle, they don't need to be an exact match. You can use a tweezer like a sternum spreader on a pair of tips with a slightly smaller nozzle diameter, but if it's too small (or the material is too pliant) they can close over the outer bore opening enough to affect the sound. Don't do it any other way, as a slightly larger nozzle will mean that sometimes you might pull the IEMs out and leave the tips in your ear canal.

 

[cel4145]

Don't do it any other way, as a slightly larger nozzle will mean that sometimes you might pull the IEMs out and leave the tips in your ear canal.

I've done that before. (lol)