Why Expensive power Cables when Romex behind Wall?

I may be naive and this may garner some 'flames' but ... I've got to believe that the main impact of upgrading a PC is not to do with the cable but more the CONNECTION. Hello ? There are two of them. One to wall recepticle, and one to the equipment, if I understand correctly. My guess is that if you simply unplug and replug an existing PC you'll end up with a better connection and hence, hopefully, improved sound. Cleaning these connections would help to.

Freezing them (I'm in Tahoe) - does this help ? Bummer that it only gets down to -20c here in winter and the better half would be distinctly uphappy if I opened the windows and shut down the stove to improve the sound ;-)

No flames--I read a post in the Asylum by Jon Risch where he says he suspects 50% of the sound in power cords is due to proper grip...

For fun, do a little experiment, buy an inexpensive steel or brass outlet cover and install it in place of your plastic outlet covers. Plug in your system and listen.

You should notice a big change in sound.

WHY?

I will spit this out for discussion.

We cannot cure world hunger & explain every improvement we hear in audio as a direct result of decreasing capacitance and inductance while ensuring a low dielectric absorption. While this is important and the common angle to view how cables effect a system it is but a small piece of the puzzle.

Since everything resonates at certain frequencies, the wire (yes, the stuff inside our walls interconnects, and power cables) will resonate too. This is called (drum roll please...) Mechanical resonance. Mechanical resonance is particularly evident when energy is applied to something. Bang that drum again.... did you hear something?

While inductance and capacitance are very important in cable design and lets not forget dielectric.... Mechanical resonance is to a great degree what we hear when we hear differences in cables (and components). With power applied to the cable, it will resonate and thus emphasize certain frequencies, audibly changing the tonal quality you hear.

Cable geometry, and material used are key in producing neato sounding cables since they can effect the frequencies which resonate and those that don't. Different conductors will all resonate differently. For example: Copper resonates at 26.530MHz, Gold at 1.729MHz, Silver at 4.046MHz, and Platinum at 21.499MHz

The effects of the resonance of the material depends on the gauge of the wire and of course whether or not it is in contact with a sound deadening substance like Teflon - rubber - Shunyata Sand ... Virtual Dynamics Iron Powder or whatever. These substrates weight down the resonance to create the sonic signature.

Make sense?

Okay how about saying it like this:

Power coming into your house is already resonating - when you plug your cool aftermarket power cord into the wall, how do you think this could effect the sound? If the cable changes the existing mechanical resonance, it will change the way your system sounds.

So when you change your electrical outlet cover to a brass or steel cover and plug in your hefty power cord, you will hear a new mechanical resonance in your system and better understand as the topic of this thread reads -- WHY EXPENSIVE CABLES WHEN ROMEX BEHIND WALL... :)

Outlet quality and contact resistance is at least as important as the inductance of the power cord itself. Silver-plated brass outlets can work wonders for dynamics and detail.

Back to the question of the last 6 feet. Here are some calculations that I did to demonstrate the effect of a good 6-foot power cord:

A typical 6-foot 14 AWG rubber cord and 25 feet of ROMEX has inductance of 7.2 uH and resistance of 235 mohms, ignoring the plug resistance effect. Therefore, the voltage drop at 20kHz will be I*(wL+R)= I*(.905+.235) = I*(1.14). With a 6-foot Magnum2 and 25 feet of ROMEX, the inductance is 5.9 uH and the total resistance is 147 mohms. This is an 18% reduction in inductance and a 37% reduction in resistance. The voltage drop for this combination will be I(wL+R) = I(.741+.147) = I(.888). So at a fixed dynamic current I, the voltage drop in the entire power feed at 20kHz is 22% smaller with a Magnum2 power cord. I would consider 22% to be significant. The reality is even more compelling. When you add in lower plug and receptacle resistance and the fact that the di/dt on the power cord will have spectra well above 20kHz with some amplifiers, the low-inductance cord makes an even bigger difference.

Bwhite wrote:
"Make sense?"

Not to me. In fact, IMO mechanical resonances account for very little that is audible in most systems. Certainly if you put your components on a thin steel shelving unit, you might get some mechanical resonance effects, but most systems do not experience this. If anything, the electrical resonance of longer cables has a more pronounced effect. You are taking the snake-oil literature out there too seriously. Here are some papers that are not snake-oil:
Technical Papers and Audio FAQ at:
http://www.empiricalaudio.com