Synergistic Red Fuse ...

http://www.audio-horizons.com/pages/fuse.html  >$118
Not one word about it improving the sound, just a lot of voodoo on impedance at 10mHz, and leaving the sound of it up to the gullible buyer, by stating " the proof is in the listening."

http://www.synergisticresearch.com/new-category-synergistic-research-quantum-fuses-furutech-hifituni...  >$50
This statement has grounds for legal action, as it's impossible, unless the fuse has a 1st 2nd 3rd or 4th order HF filter inside it. 
"Fuses significantly outperform all other high-end fuses on the market and are "guaranteed to deliver a noticeable increase in sound staging", resolution and air thanks to a lower noise floor and blacker backgrounds."

http://www.synergisticresearch.com/synergistic-researchs-new-reference-red-fuse/  
Also grounds for legal action, I'm not a lawer but I think the first two words (All told) are the get out of jail free card.
" All told SR RED fuses significantly outperform every other high-end fuse on the market and are the only fuses guaranteed to deliver a significant increase in system performance or your money back. When compared to our award winning SR20 Quantum Fuses, SR RED Fuses sound more refined with smoother highs and more linear frequency extension from the deepest bass to the highest highs; no small feat given the remarkable performance of our original SR20 Quantum Fuses. ."

I've never come across such blatant B/S in all my years of audio, sorry yes I have,  "Shun Mook Mpingo Discs"

You guys should be ashamed of yourselves for preaching this rubbish, I hope your getting well compensated for it. 

Cheers George 
  

Georgelofi said,

"I’m not a lawyer."

Gee, no kidding? You probably don’t know that amps, speakers, whatever frequently don’t measure the same as the stated specifications when tested. Would you believe they never measure the same in different rooms? Who ya gonna call? Ghostbusters!

Someone once did try to get the FCC on my case for the Teleportation Tweak, I will admit.

I don’t think anyone has ever tried to measure Shun Mook discs but they’re quite effective in any case. In fact I’d go as far as to say they’re Super Duper. I actually have experience. Can you believe it?

This all just substantiates my contention that this is a classic case of Advanced Audiophiles vs uh, let me choose my words carefully - the Opposite.

George,  the Audio Horizons site does talk about sound quality here;

"with a level of detail and refinement so sweet, delicate, and with such presence and immediacy—well, it will make you smile."

Come on now please be intellectually honest. Your question was answered and the companies do tout better sound. These are just what I found in 10 minutes!

As to the truth of what they say on technical matters, you may be right and I am not smart enough to pick a dog in that debate. I do know they impact sound however. All you have to do is remove one and insert a copper slug or bypass one to know they certainly impact sound. I have done it and know the result. I have also heard one fuse sound different then another and one fuse increase my enjoyment of music more than another. In this regard I am like you in that I know the truth about fuses and no amount of prose on these threads really means anything as I have experienced the truth already.

A couple of further comments regarding the statements at the AH site:

1)As I mentioned in my previous post, it follows from the second of the two statements I quoted that a "typical fuse" provides zero noise rejection. Which sounds right to me! Their first statement I quoted says that their fuse increases "high frequency noise-rejection fifty fold over that of a conventional fuse." It’s worth reflecting upon the fact that 50 times zero is still zero.

2)Regarding their statement about the 10 ohm impedance of their fuse at 10 MHz, a far more effective approach to attenuating 10 MHz noise, as well as noise at other similarly high frequencies, would be to put a suitably chosen ferrite clamp costing a few dollars around the power cord, near the IEC connector on the component. Which is not to say, though, that in a given application there would necessarily be any benefit from doing so.

Personally, I would always much prefer to see a manufacturer say something along the lines of "frankly, we don’t know why it works but it does," than to provide misleading and specious technical explanations.

Best regards,
-- Al

Actually, and I apologize for repeating myself for the umpteenth time, but there are already enough perfectly good reasons why aftermarket fuses work better than ordinary fuses without having to go down rabbit holes like noise rejection and how many dB dance on the head of a pin. Furthermore why would anyone say, "We don't know how it works, we just know it does? That would be ignorant and not serve any purpose. If I can be so bold, the only ones here who are claiming they don't know how aftermarket fuses work are the pseudo skeptics. No offense intended.