Sadly, the audiophile world has been full of things that are ajbect bullsh1t. They come and go in fads.
I've been an audiophile long enough to see a lot of "you're mad if you don't buy this tweak", "it's essential" fads come and go. Who, for instance, still uses:
* Green pen on their CDs
* Drilling "anti-vibration" holes on their CD spindles
* A Tice Clock
* Tuned-mass dampers
* CD Clarifier gels
* Contact enhancer fluids
* GSIC (Golden sound Intelligent Chip)
* Cryogenically treats their cables
* Cryogenically treats their CDs
* Uses the "Cable Cooker" (how does this go with cryogenically treated cables I wonder - can you "cook" cryogenically treated cable for even better sound??)
* Cryogenically treats their valves?
* Uses those stupid plastic cable suspenders?
* Hospital grade power outlets
* CD demagnitisers
* Marigo Magic Dots (there is actually a thread on this one here -
Call me crazy but they (magic dots) work!)
* Talisman magnetic optimiser
* Black Diamond room treatment crystals
* Black Diamond cartridge compliance optimiser
* Orb Audio Cartridge Warmer
* Full system demagnitisers
* Keeping EQs out of the system (now we are adding them to the system!!)
* Worrying about absolute polarity
* Stores files as WAV instead of FLAC
* Swapping out for audiophile fuses
* Jumpering unused inputs on your preamp.
Who still cares whether Linux sounds better than Windows or worries whether transcoding to FLAC or WAV sounds better?
Then (in the most reprehensible of all), there have been many "audiophile" components (and audiophile priced components) from ostensibly "respected" audiophile companies released which were just rebadged cheapo Jap-junk - The Simaudio Moon CP8 (which was just a Denon) and the Goldmund Pioneer DVD player are two of my favourites.
Honestly, I could go on all day. Each of the above have come with "expert" reviews and been branded "essential" and "best value improvement", etc.
Fast forward to today - we have a whole new set of contemporary tweaks that everyone is talking about. Not surprisingly, a lot of it relates to computers. We see bullsh1t things being branded as essential like:
* Audiophile ethernet cables
* Audiophile USB cables
* Audiophile network switches
* Upgrades to computer power supplies (switching power supplies in a computer can be heard throughout the whole audio chain, you know)
* etc.
The other one that seems to be popular today is around other cables:
* Power cables
* Power plugs
* Network and USB cables (being a variation of the aobve)
* You can include directional RCAs and dielectric biasing and all that wonderful bullsh1t as part of this one.
Sure, plenty tweaks have been ground in science. Those are the tweaks which have generally stayed around for longer than a few years. Things like room acoustic treeatments, use of balanced cables, spiking loudspeakers, et al.