Power Filters - eliminates noise to speakers ? Really, or just sales hype

[omikey]

OK, so hit me with it !!!

Am I fool for thinking that I'd buy power line filers. Such as the Monster filters that do everthing from surge protection to complete circuit isolation for each component that you plug in. These things range in price from $20 to over a $1000.

Of couse the sales pitch, we've all seen that nosie maker they have, but here's the real question:

Is it detectable when you listen to music. Does the filter in fact improve speaker sound quality, and also video they say, by removing (flitering out) noise on the 120v source?

If the answer to the above question is yes, then what level of filtering is best, since there is a range of products I'd like to know where the best price point is.


Thanks,
Mike