What About Loom Theory?

Here is a summary and further elaboration of my comments in the thread referenced in my post above:

1)The sonic effects of a power cord will depend to a significant degree on the sensitivity of the component the cord is used with to variation of AC voltage; on how much the current draw of the component fluctuates as a function of the dynamics of the music (that fluctuation being very small for preamplifiers, source components, and Class A amplifiers, while being large for Class AB amplifiers and larger still for Class D amplifiers); on the AC line voltage that is present at the particular location; on the magnitude and frequency characteristics of RFI which may be generated by the component and fed back into the power cord; and on the sensitivity of other components in the system to that RFI.

2)The sonic effects of a speaker cable will depend to a significant degree on the impedance of the speaker; on how the impedance of the speaker varies as a function of frequency; on the criticality of woofer damping to the particular speaker; on whether or not the amplifier utilizes a feedback loop from its output; on the sensitivity of the amplifier to spurious energy that may be introduced at its output and couple from there into that feedback loop; and on other speaker-dependent variables.

3)The sonic effects of an analog interconnect will depend to a significant degree on the output impedance of the component driving the cable; on whether the cable is balanced or unbalanced; on the susceptibility of the components that are being connected to ground loop effects; on whether the signals being conducted are line level or phono level; if they are phono level on whether the cartridge is a moving magnet or a moving coil; and on other variables.

One interesting example: If an interconnect having relatively high capacitance is compared with one having relatively low capacitance, and if everything else is equal, the higher capacitance cable will produce a duller and more sluggish response in the upper treble region if used as a line-level interconnect (especially if it is driven by a component having high output impedance), due to the interaction of cable capacitance and component output impedance; while the exact opposite result will occur if those same two cables are compared in a phono cable application and driven by a moving magnet cartridge, due to the interaction of cable capacitance and cartridge inductance.

4)The sonic effects of a digital cable will depend to a major degree on the risetime and falltime of the signal that is provided by the component driving the cable; on the propagation velocity of the particular cable; on the happenstance of how well the characteristic impedance of the cable matches the output impedance of the component driving it and the input impedance of the destination component; on the jitter rejection capability of the DAC that is being used; on the susceptibility of the components that are being connected to ground loop-related noise; on the data rate of the signal that is being conducted; on the relationship between cable length, signal risetimes and falltimes, and cable propagation velocity; and on other variables.

One interesting example: It is easily possible for digital cable "A" to outperform digital cable "B" in a given system when both cables are of a certain length, and for cable "B" to outperform cable "A" in that same system if both cables are of some other length. The happenstance of the relationships between cable length, signal risetimes and falltimes, cable propagation velocity, component susceptibility to ground loop-related noise, and the happenstance of how closely the impedances of both components and the cable match, all figure into that.

Given all of these component and system-dependent variables, happenstances, and dependencies, it is hard to conceive of how, as a general rule, a single-manufacturer loom would necessarily stand a greater chance of being optimal than a mixed set. For that matter, it would seem likely to have less chance.

IMO, YMMV.

Regards,
-- Al

Hi Al:
The principles you refer to are unassailable and indeed important variables in cable selection. One other principle that my ears taught me over the years is that a Nordost cable has a different sound than a Cardas cable and, absent an extreme mismatch, that sound will be consistently audible with a large variety of different components.

The original poster asked for an explanation of what loom theory was, so I provided the only documented source that I know of where it is explained. I'm not promoting it or saying that it's the answer for everyone, just trying to answer the poster's question.

>>Given all of these component and system-dependent variables, happenstances, and dependencies, it is hard to conceive of how, as a general rule, a single-manufacturer loom would necessarily stand a greater chance of being optimal than a mixed set. For that matter, it would seem likely to have less chance.<<

This may be the case, but given that very little is necessarily true in audio, that gives the claim much less interest or force. Where do we stand if we throw out the word "necessarily"?

It kinda sounds like the claim is saying: because there are so many variables and possible combinations the odds of any single set of power and signal cables working optimally in all possible systems are better for a randomly chosen set of wires than a specific loom. How could we test that?

Or, does the claim say that a loom of power and signal cables selected from the same manufacturer has less chance of working better in a specific system than a random set chosen by, say, a monkey? :) 
 

The audiophile world is filled with anecdotal musings. In some ways it is a positive, but it is also a great flaw.