I have only heard the x10 and the Eterna. The x10 has a huge mid bass bump but its highs roll of way too soon for my likings. The impact is maybe slightly warmer than the Eternas but about more in power, if my audio memory is correct that it. Joker should be able to help you out though. He has heard all these and 138 more critically. LOL. And BTW what do you mean by reference point? All these are far from neutral reference quality. 

I have X10i which is basically the Iphone version of the X10. Smaller PMPs like Sanza Clip+ would not be able to drive X10 well and as a result the bass response is weak and the high gets rolled off. But when the PMP is powerful enough like e.g. Cowon J3 or Zen Touch 2 the X10 has plenty of bass that is very well balanced across all the spectrums. Other IEMs like IE8 or MD may appear to have more bass but X10 is a lot more better balanced and clear. If you are not prepared to spend on a good PMP or a portable AMP, don't get the X10.

The X10 has less bass than the IE8 and the Eternas. It has more than the Hippo VB. 

X10's midbass is strong, but not as crispy as some others like the Metro.Fi series. Has a bit less impact than the Turbine Vanilla.

The sub bass is sorta there but not really. Extension isn't all that great, but not surprising as not many IEMs can really go that low.

Quote:

Originally Posted by Mochan 

 

X10's midbass is strong, but not as crispy as some others like the Metro.Fi series. 

The sub bass is sorta there but not really. Extension isn't all that great, but not surprising as not many IEMs can really go that low.

You get that impression? I've got the Metro.Fi 170 and 220 and to me they're both essentially garbage across the whole frequency range in comparison to X10 (except maybe the highest audible bands), and completely lack detail and separation - and I'm not saying that just because they're cheap. X10's separation of bottom end and mid-bass is one of it's strengths IMO.  

X10 may not be able to hit the lows of IE8, but it is still a very heavy hitting bass response iem - I don't know if they actually hit their claimed freq. response of 5hz but they definitely go very low. I remember reading a review where someone claimed they tested a response out of them at 12hz.

The bass on Image X10 is deep and very smooth but some tracks feels extra smooth in bass region. The Custom 3 Bass is crispier, it's goes deeper and more punchy with greater details in midrange area.