Have someone tried the Yurbuds?
Revision3 > Tekzilla Daily Tip > Episode 533: CES 2010: Yurbuds are Custom Earbuds for $29 - Yurbud, Yurbuds, earbud
looks interesting...at least for $29 it's worth a go! perhaps we'll see other companies follow suit for cheaper customs?!
I've got them on a pair of Sennheiser MX-450s. In stock form not brilliant, but adequate and better than stock Apple buds.
Previously, could never get them to fit and stay in my ears. Consequently the bass disappears, and you have to crank the volume up to hear. also ambient sound (e.g. public transport, which is where I wear them mostly) intrudes a lot.
Yurbuds address all these problems, with a big but.
Firstly the good. They now stay in my ears. Ambient sound is substantially reduced. Bass is back.
The big but. Sound is severely compromised. Bass is ill defined, muddy. And depending on how well you have them stuck in your ear, the bass can overwhelm. Mid-highs are peaky, highs almost non-existent.
Only got them because my ultimate ears canal phones broke, and I thought I could resurrect one of my collection of old buds. Guess I bite the bullet and replace the canal phones.