What are you trying to tweak improve?

As I see it, the tweaking is like using a equalizer. Any tweaking method will affect certain frequency(increase or decrease it). My experience is that using hardwood like Ebony or Purple Heart are very effective in altering the sound. When using it properly, it adds harmonic to vocal or any kind of acoustic instruments. Making it sounds very natural, full of life and very realistic in the presentation. Other material like the Black Diamond Racing cone, the BDR shelf, carbon fiber board, grainite or marble slab all have their own character.
In general, hardwoods give the system more warm, musical and softer presentation.
Other materials like BDR cone/shelf, carbon fiber board, grainite/marble will give the system a more bright, analytical, sharper(less natural image), dryer presentation.
Usually a well-tuned system will need to a mixture of the above materials in order to make it sounds nice and balance.
It is like cooking, everyone have their own mixture of spices......

Every time I tweak or upgrade, I find myself listening for improved realism -- the illusion of musical presence. Specifically, I'm looking for clearer highs and stronger dynamics.

At this point, I'm most interested in obtaining the blackest background/lowest noise-floor possible. I believe that so long as one perceives that the other areas mentioned have been addressed, I believe this lowered noise-floor will simply enhance sound-staging, imaging, etc. and add more micro-dynamics bursts and bites from a dead silence to give the music more of that 'live' sound.

To reach this goal (not yet attained), I've installed custom 10 gauge 99.95% OFC romex, three dedicated circuits/lines, aftermarket audio-grade electrical outlets, floated the ground on all three circuits, and am using dedicated in-line power conditioners in place of power cords for each component. The only thing I can think of next is convert my amp from 115volts to 230volts and convert the amp's circuit to 230volts. I'm just too nervous to do this myself right now.

I'm certainly open for suggests.

-IMO

Mapleshade has some incredible tweeks that live up to
their billing. Talk to Pierre. He knows tweeks!

Turntable base for isolation. I see commercial ones available for $1250 ... and more ... and I nearly faint. I'm working on a prototype, with assistance from engineers at Sorbothane. This is a granite slab (1.25" or 2.50"), on an air bladder, in a wooden frame which is all glued and doweled (no nails or screws to vibrate), which sits on engineered Sorbothane feet. Since the guy who sold me the granite sold me 10 pieces, once I get this tweaked to its maximum potential, I might put some up for sale here. But the results so far are very promising :-)