[konchanboy]

I presently have a cheap pair of Sony mdr-xd100 headphones. My question is: Is it worth shelling out an extra $90 for the increase in audio quality, by upgrading to an mdr-v6, or should I keep my present headphones? Because if, for example, I will get essentially the same frequency response from going from the xd100 to the v6, then I don't think the $90 is worth it.

 

[MegaMushroom]

Frequency response isn't everything when looking at a headphone.  At this point build quality and sound signature play a major role.  As does comfort.  If you compare my Grados to a set of Beats, they should have the same frequency response, but they couldn't be more different. I'd look around a few of the reviews here, and see if this is something you want to upgrade to.  (Or was I talking about frequency range?)
 
Can't remember exactly since it has been a while, but they should be pretty decent cans.  They've been around for a while now. 

 

[PFULMTL]

Specs mean nothing.  Go for it.  Since that is a popular headphone, try looking for a used one.

 

[squallkiercosa]

If you like the ones you have I guess you shouldn't. Don't upgrade I would say.