Objective vs. Placebo relating to system changes


I am continually baffled by the number of people that are convinced that changes to power cords, speaker wires, interconnects, etc. in their systems result is objectively real changes. While I won't go so far as saying that making these changes absolutely doesn't make a difference, I would love to have the resources to challenge people prove it to me and test it with my own ears.

Here's what I would do if time and financial resources were no object (I'm visualizing retired millionaires that are audiophiles).

I would build a listening room where the only components in the listening space were the speakers and the speaker cables coming through opening in the wall where the rest of the system was setup. The idea would be to allow the test subject the opportunity to create their system of choice and then have the opportunity to become very familiar with the system by spending hours listening. Then I would let them know when I was going to start changing different components on them on a very random basis and they should report any changes that they heard so we could link the changes to any potential changes on the other side of the wall.

Here's a short list of things that I'd try:

(1) I would replace the upgraded power cord with the stock unit.
(2) I would install or remove isolation (e.g. Nordost sort kones) devices from a component.
(3) I would replace interconnects with basic quailty products.
(4) I would replace well "broken-in" cables with otherwise identical new ones.

Depending on the results of doing these test slowly over a period of time I would consider swapping out some of the more major components to see how obvious a macro change was if the listener wasn't aware that a change had been made.

I can tell the difference between new and broken in speakers (on ones that I'm familiar with) so I know this break-in is very real and would also not be at all surprised with differences from amplifiers and analog sources being obvious. I'm not as sure about digital sources.

So the question is, what components in your system would you be confident enough to bet, say $1,000, that you could identify that something changes if it was swapped out?

In my system I am sure that I could identify a change in amplification or speakers, but highly doubt that I could do the same with any cables, isolation devices, or digital sources. Maybe I just reduced myself to being a non-audiophile with low-fi gear?
mceljo
Cars do run on water (actually hydrogen) in Iceland. The issue isn't technology, instead it is infrastructure as they have very special "fuel" stations making it a similar problem to going all electric. I don't know about hydrogen, but in some places the electricity to charge a car can cost more than the gasoline and if the electricity is coal generated it isn't really an improvement overall for the environment. At this point the cost keeps people from getting excited about going away from Dino cars. Eventually, one of these cars will get a Bose stereo and this post will be back on topic.
I find it interesting that many of those who come close to being in the position to do such an experiment - namely audio reviewers and editors of audio magazines - say outright that they do not 'believe' in blind testing. Why not? I don't mean to imply that components don't make some difference, but I do think many of those differences are much harder to identify, and that it's even harder to state one is preferable to the other.
When you get to the point that you do not hear a difference (or can't afford the next step), stop. Of course, that point will be different for different folks. I like music; but I view audio as a drug addiction. Every so often I must raise the bar to get that reproduced music rush. I upgraded my cables one step at a time as I saved up the money and got over my reticence to let go of my cash. Each time my hope was that I would not hear a large difference and could send the component back. Then I could listen with satisfaction and be richer for it. I was not so lucky and much to my disappointment, even the expensive power cord on my CD player made a significant improvement. I don't want to come off as poor me, I just get a much bigger kick out of the cheap tweaks that work but I can't rest knowing something could be improved.
****I am an engineer so my gears are always turning and thinking about this stuff.****

Mceljo, I am sincerely trying to understand where you are coming from and not simply trying to take you to task, so please, explain how your above comment jibes with your comments in this other thread. IOW, why does an engineer need to (or feel he needs to) ask these other questions? Because you are an engineer, I would not be surprised at your skepticism re the subject of this thread, but seems to me an engineer would not have to ask the following questions:

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1383190688&&&/How-do-I-break-in-a-tube-amplifier-
Maybe he is a Civil Engineer (my first area of study). We learnt physics and applied maths and basic electrical engineering.

Could have an "engineering mind" without specific knowledge of electronics.

Regards,