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
Mceljo, My friend, with all due respect, I think a lot of us are baffled why some people fail to understand that rejection of and shielding against RFI and EMI can make an audible difference in a high end system. It’s not necessary to invoke metaphysical explanations.

It is also not necessary for everyone to understand all of the science and engineering that may be involved. Sometimes it’s OK to take an Edisonian approach and be guided by empiricism. There are plenty of people who use a toaster without understanding how it works. If that were to be a requirement for use of a toaster, there would be a few people without toast.

If you are in Indianapolis, send me an email and I will demonstrate in 10 minutes that PCs make a difference that is immediately obvious.

At the end of the day, perhaps you may want to entertain the possibility that not all of us are fools. I'm not sure what it is you wish to accomplish with this thread.
"shielding against RFI and EMI can make an audible difference in a high end system"

That's a good one that often relates to ICs.

Encompassing my low level phono set up transformer device with a makeshift external mu metal surround is a clearly audible example of this I can point out in my experience, but the concept extends to even more common line level signals, though the effects at higher levels is surely more subtle. Science accounts for why this would be the case fairly well I would say. Using shielded ICs (like the MITs I use) versus unshielded (the DNMs I use and prefer for this) alone also makes a clear difference in my case.
Mceljo - here's some basics of the science...

In simple terms it's all about conductivity . i.e. how fast a metal can conduct an electrical current.

King of the hill is silver closely followed by copper - everything else pale by comparison.

See -
http://metals.about.com/od/properties/a/Electrical-Conductivity-In-Metals.htm

Alas - not all copper is equal - there are different levels of purity and some providers alloy the copper for price reasons - impurities reduce the effectiveness of the cable resulting in a less dynamic sound

Now that's just conductivity of the base metal. Wire needs insulation between the conductors - making a cable introduces capacitance and inductance into the equation. With an audio signal impedance becomes a factor - it's like resistance except that is frequency dependent.

Some cable may have a high capacitance which can effect the sound e.g. make it bright, or ir can effect the operation of the attached component e.g. Naim amps do not like high capacitance speaker cables - in some amps high capacitance cables can cause their internal circuit to oscillate and then they sound like crap.

So where do power cables fit in - well, they control the flow of current to the amp.

An underated power cable will not be able to supply sufficient current to an amp when it tries to reproduce transient spikes in the audio signal - in that case the voltage in the internal circuit drops ever so slightly which prevents the amp from adequately amplifying the signal, which introduces distortions into the waveform.

Now complicate that with the fact that there are two amps operating and what happens is the distortions in both amps are not exactly the same, which contributes to an imbalance between L/R channels, which effects the spatial image.

This is just the tip of the iceburg - factor in all the other cable discoveries that have been discovered e.g. skin effect etc., and you end up with the cable science we have today

The one common design point you will find in quality components is their substantial power supply. It is designed to allow the component to operate as best it can in a less than perfect power environment. More modestly priced components may actually respond better to a cable upgrade.

Case in point - my neighbour bought a $200 boom box - I replaced the 18 gauge cable with a 14 gauge cable from Home Depot - she could not believe the improvement in dynamics, bass response and clarity - and she is no audiophile.

So, will quality components benefit from good power cables? - you bet they will, but the improvements are often in the area of enhanced micro details that contribute to better instrument isolation and 3D spatial imaging

Will replacing a single power cable make a noticeable difference - maybe not at first, but when you replace other power cables or interconnects on components in the audio chain the improvements may become apparent.

I decided to replace my entire power corridor
- dedicated line from the breaker panel
- quality Pass and Seymour outlets
- silver plated copper plugs and connectors
- quality power cable that I constructed myself

The benefits are very apparent.

I do not expect you to become a convert, but if you are ever in the Toronto area I also will happily demonstrate, like brownsfan, the difference cables made in my modestly priced system - it's very noticeable.

Hope this helps
There are many people on the Linn/Naim forums that claim to be able to hear the difference between the two sides of the felt mat. All I can say is that I'm glad my hearing is not as good as theirs. Never assume that because you can't hear something that nobody else can hear it. It's like saying that you can't read fine print so nobody else can. We're all different.