Switch to silver for a treble boost?

Silver has absolutely nothing to do with treble sparkle. Some silver is neutral sounding..some have rolled off treble, and some...only some have a high end "sparkle"

Silver speaker cables arrived... initial feeling is that they have made little difference to the upper treble, as a couple of you predicted!
My system still seems to sound as if there's a sheet over the speakers.
However, they did alter vocals in a nicely unexpected way. To my ears, voices now seem better defined and separated from the backing music, as if the singer has taken a couple of steps towards me, and this was using a few of my favorite and familiar tracks.

I might report back again after a few more days listening.

Carl, I tried a similar test to get a little more treble "air" and went with the popular silver Signal Cable.
The results were less than stellar. I found the cables to be less transparent overall. I'm VERY skeptical of mega buck cable's and thier supposed differences, but compared to some Nordost cables which I recently borrowed from a local dealer, the Signals just sounded more laid back and slightly veiled. This may be suitable for some but when looking for a bit more top end "sparkle" the silvers failed.
Good luck in your findings

Alun, after a few weeks of the silver speaker cables (locally hand made from "German surgical grade silver" according to maker), I have to agree. The difference from my previous heavy copper was small indeed, but I accept that could also be system related.
The silver has produced a slight lift in the upper-midrange, which has helped nicely with vocal clarity, but certainly didn't produce any extra treble distinction or "sparkle" that I was hoping for.

I would add that these cables (2.5 meter pair) were only $100, but given my system I'd be reluctant to spend more than that.

Try cables with lower capacitance. There will be less HF rolloff