What’s your vote for the most ridiculous, overpriced, and useless tweak?

@whostolethebatmobile 

What about my vote for the Maxiimus P16?
useless - it generally makes the sound worse, smears focus and destroys the soundstage.

Curious - how do you know what it does to the sound? 
Do you own one?
How do you guys even hear about some of this stuff?
Surprising to see the folks at Mono&Stereo were "Gobsmacked" over this item.
I am thrilled to remain blissfully ignorant of most of this stuff. 🕶
However, I did have a seemingly sane person explain how the "blue fuses for $150 each" transformed the sound of his amp/system.  💥🚀💨

Yes I own one. I would not have the gall to criticise something without having heard it in my own system for a long period. I know exactly what it does to the sound (but not how it does it). It’s main effect is to artificially exaggerate front-to-back dimensionality (not the same as depth, because sounds appear to come forward from the speakers), at the expense of soundstage accuracy. Try to imagine a processed, blurry 3D photo compared to a normal crisp 2D photo of the same scene. That’s what it does to the sound.

If one guy must already know that some facts are unexplained yet by engineering science and tough these facts are linked to audible experience results it is Geoffkait :)
I dont pretend to explain anything, tough in my system there is a difference...But I am ok with you to put that tweak in the category ridiculous but not overpriced nor useless (orange light increase placebo effect perhaps)...My best to you Geoff...

Thanks for the explanation.
Makes me wonder if that is one reason some equipment manufacturers don't subscribe to tweaking (beyond providing good power, solid support, and room treatments) since in many cases the tweaked result may be different but not necessarily better or, at best, subjectively better - i.e., some like it some don't.
I guess it boils down to how much time, energy, and money someone is willing to spend to change the sound of their system by 5% +/-.
Since I have the power, support, and room thing covered, I continue to find component/speaker changes move the ball way more than whether I use Herbies feet or cones under my gear, what fuses I use, whether the EVS ground enhancers are plugged in, whether my high end zobel networks are attached, etc.