Why Expensive power Cables when Romex behind Wall?

Albertporter wrote:

My comments were meant to bring to light the fact that mechanical, electrical and magnetic interference all produce changes in a high end system.

I certainly agree with this. Particular systems can have effects from all of these. What I do not agree with is that mechanical resonances are one of the most important factors in a typical system.

What might be happening with your powered subwoofer is that it might be using a class-D amplifier or a switching power supply. These can create large switching noise on the power line and create fields that can get picked-up as well. If this is the case, I would recommend using a ferrite on the power cord to each subwoofer. Have you tried this? Unless the other cables are draped on top of the subs, It is hard to believe that they are picking-up noise this way.

My sub woofers can present a problem for the main system in that they affect resolution and distortion levels of my Soundlab U-1.

That being said, this is a two channel issue and since the subs are a deterrent to stereo sound quality, they are not supplied with signal.

However, power even being AVAILABLE to the subs in an inoperative mode damages the reproduction quality of the Soundlabs.

I have my own opinions as to the cause, but since the HT system is used three hours a week, and this is not a problem with Dolby 5.1, the solution is to save electricity and unplug the offending product.

I do the same thing with my DSS receiver, DVD player, and Dolby 5.1 processor. Disconnecting them from the wall mains is a small but audible improvement for two channel analog reproduction.

As for details of my system's wire and cable dressing, a visit by way of my provided link makes it apparent that it is not an issue in this discussion.

As for mechanical resonances, if a system is pushed to a high enough level, solving miniscule problems can be a significant improvement.

I think this dead horse has been beaten enough.

I am confident my Purist interconnect and power cables are not an issue, and wish you success in marketing your products.

Do power cables make a sizeable difference? I'm no technical expert, but I'd like to share my experience.
Until a month ago, despite having a high end system (comprising Capitole MKII, KR8000 monos etc.) I was a total disbeliever in power cords. All power cords in my system were stock cords. Soundwise, I was satisfied.
For quite a while I had been wanting to try quality power cords, but there are no dealers in my country, Mauritius, which is close to South Africa is very far away from the US and Europe and dealers whom I contacted for a trial often limited the money back policy to one month. Since postage & customs formalities would take about two weeks for the products to reach me, there would hardly be any time left to audition and return the cables within the specified limit. The risk was too much.
A few weeks ago, I decided to make my own power cords with some Audio Note AN-D speaker cables (retails for about $10/metre). I made 3 cords; those on the power amps were grounded while the one on the CD player was not.
Result: well, after two days, I could not believe my ears. A huge amelioration in musicality, smoothness, detail and soundstage. Almost creamy and gently massaging my ears.
To be honest, my experience tells me that the addition of power cords had a better impact in my system than my Audio Aero Capitole MKII replacing my Micromega Stage 6.
I don't know whether that would apply to every system, but my advice is, one audition is better than 100 debates, as already mentioned ealier in this thread.
Since I am curious to know how far the performance of my system can extend, I am still willing to try megabucks power cords but can't find any dealer willing to send me 3 so-called high end PCs for a 2 months trial period, everything paid in advance, but fully refundable. I am even willing to pay a fee of $100 for the trial if I don't end up buying any of the three cords sent to me. Anybody (including fellow audiogoners) willing to help? thnks.
Dr Jawa Lallchand
Mauritius

Albertporter - something just occurred to me form waht you said. I do not mean to kick a dead-horse, but since you say that the 2-channel system is affected when the subs are plugged-in, but not turned-on, I suspect a ground-loop may be at fault. Usually these cause hum, but not always. One way you can test this hypothesis is to leave the subs on and plugged-in , but disconnect the IC's to both subs. If this has the same improvement effect as unplugging power to them, then it is definitely a ground-loop at fault.

If this is the case, the cleanest solution to this is either to unground both subs with AC cheater plugs or run isolation transformers to one or both subs.

I think it's clear from the entirety of this discussion that each system requires its own unique treatments in terms of electrical and mechanical conditions. However, I do agree that there are some activities which will transcend the individuality of the system, and be virtually universal in their behavior.

#1 - Make sure your power is clean, and constant, regardless of the methods used to achieve that.

#2 - Reduce stray hum, RFI, and EMI fields surrounding your equipment, and block, or otherwise deter these fields from affecting your equipment, including cables.

#3 - Consider your equipment and cables to be "vibration antennas" and attempt to reduce, or control, the mechanical resonances that may be induced by external sources. Attempts to control inherent, natural resonant frequencies can be counterproductive.

#4 - Remember that all signal carrying wires have an inductive field around them that is actually a part of the signal. Attempts to suppress this will affect the quality of the signal in the wire. Allowing these unsuppressed fields to interact with other unsuppressed signal carrying wires could be detrimental to sound.

#5 - Place transformers and other large magnetic field generating devices far enough away from sensitive items which may be influenced by the fields.

#6 - Just because it may be difficult/expensive to do something behind the wall does not mean that you may not reap improvements from these efforts. It is a known fact the the Romex moves enough from its own movement inside the wall, that it can cause a connection to sever from metal fatique, and this is why the Romex is to be stapled within several inches of the rough-in box. We haven't even discussed whether the conductive staples on the Romex could be a factor, when these are plentiful, and in direct contact with the Romex sheath, and even pinching the wire in some cases. Maybe non-conductive staples may play a part. Maybe distance between staples may have some electrical or mechanical effect.

#7 - Make good, clean connections wherever any connection is to be made, and periodically clean them. Including in the outlet boxes, and breakers.

#8 - Use good grounding tecniques.

#9 - If power conditioning is required in your area, due to grungy power from the street at varying times of day, use it.

#10 - Use your ears to decide the value of the modification.