[ZARIM]

I think there is surely huge difference in bass between bassheavy highend universal IEMs and customs in soundstage, bass impact, details and presentation.

 

[koonhua90]

There will be differences, assuming if you get a good seal (sometimes even customs will have problems, but it is less likely to happen). Just remember that it's diminishing return, so the higher you climb, the less of improvement you will get. Logically, I do not expect a custom that cost 3 times more than an universal IEM to have 3 times the improvement. Maybe 50%, maybe even 80%, 100%, but not 300%. In fact, scientifically, our hearing is quite limited. Imagine if we can hear below 20Hz, and above 20Khz (and not all people can even hear up to that frequencies)....