Are Expensive Balanced Interconnects Necessary?

Depends on what you mean by expensive.  Having a balanced preamp to amp as well as two balanced sources the differences between cables is nearly identical to the differences in sound for single ended cables.   

I tried basic balanced cables including Benchmark and two pro cables but found them to not sound as dynamic or clear as the Van den Hul hybrid and Nordost blue heaven cables.  

They make the same difference and are worth the investment for me.

So, I gather that the answer to the original question is definitely maybe, or certainly could be.

@vonhelmholtz indeed and I personally wished that wasn't the case because it would make it so much easier!

So, I gather that the answer to the original question is definitely maybe, or certainly could be.

@vonhelmholtz I think that it would be difficult to tell the difference between a $5 and $5000 XLR cable with any certainty in an ABX test.
But if it has been done, then we should be able to find it.

There are countless personal testimonials and poetic prose in magazines, that proclaim the money is well spent… just nothing that most would consider evidence being extant.

Clearly, single ended interconnects yield sound benefits as you move up a manufacturers product line, but do balanced cables yield the same improvement?

And not all the way up… sometimes different systems like different RCA cables.

The fact that recording studios are using regular cables, sort of suggests that:

1. It doesn’t matter 
2. or what ever was lost happened already