MIT Love 'em or Hate 'em

Transmission lines? Do you have any idea how long a speaker cable would have to be in order to start showing transmission line effects?

Check it out: Let's go as high as CD reproduction of frequency and say that we're throwing a 20kHz signal down the old pipe. Now while the speed of sound is decidedly slow in air, the speed of an electrical signal in a wire comes close to the speed of light. It gets bogged down a little by the insulator, but a common speed is about 70% of the speed of light.

Light travels at about 300,000km per second, or approx. 186,000 miles per second. That's fast, so let's slow it down and put some plastic in the way - a little PTFE and we've got it down to 70% of that speed, or 130,200 miles per second. (Disk brakes, wouldn't ya know...)

Now, 20kHz means that the signal is oscillating 20,000 times per second. If we want to figure out how long a single wavelength @ 20kHz is while travelling in the pipe, we just need to divide 130,200 miles by 20,000. In this case we get a wavelength of 6.51 miles, or 34,372.8 feet

Double that for 10kHz (68,745.60 feet)
Quadruple that for 5kHz (137,491.2 feet)
Octuple that for 2.5kHz (274,982.4 feet)

When would you begin to see transmission line effects? Full wave? Half wave? Quarter wave? Eighth wave? 1/1,000th wave?

Let's get kooky here and say that transmission line effects may actually contribute some sideband funkies at 1/4,096 wave - lets' see how long your speaker cable would have to be (@ frequency) to show up some of these tranmsmission line effects that the magic boxes seem to cure:

20kHz @ 1/4,096 wave = 8.391797 feet (do-able)
10kHz @ 1/4,096 wave = 16.783594 feet (less do-able)
5kHz @ 1/4,096 wave = 33.567188 feet (much less do-able)

Now ... what are the chances that there are any registerable transmission line effects at 1/4,096 wave?

Er ... none

You'd be lucky to "experience" transmission line effects at 1/16th wave which, at 20kHz would require a 2,148.3 foot long speaker cable.

Phase delay between current and voltage? You'll have to fill me in on what this means, because I have absolutely no idea at all.

Phase "delay" is a function of time and, therefore, a function of frequency - frequencies are susceptible to phase shift, but voltage and current? Voltage and current are not - I repeat for the deaf - NOT the "ingredients of sound". They are, first of all, two different things and second of all inextricably (for audio purposes) intertwined by Ohm's law (V = IR, I = V/R, R = V/I)

Sound is, simply: frequency and amplitude. If you want to get a little more detailed, throw in rise time and slew rate. Power @ frequency is where you need to be focused because in order to move air the system has to do work, and that takes power. So, on to power factor (which describes the efficiency of a power system) and its correction:

I can't for the life of me figure out how a filterbox corrects for the power factor of the variable output of an audio power amplifier with its varying frequency and amplitude along with varying impedance @ frequency. Even if you could reliably characterize a "power factor signature" in a single system, the "signature" is going to be different from amplifier to amplifier, and speaker to speaker, and from the almost infinite variations between choices of amplifiers matched to choices of speakers - making any generic "power factor correction" magicbox impossibly crippled to work optimally in any but a single, originally characterized system.

Power factor correction is typically a power supply solution for inductive loads - and the solution itself is typically just a bunch of paralleled capacitors (as reactive current "generators"). So if the magic box is performing "power factor correction" it would be evidenced as oddly high parallel capacitance - and with the combination of series inductance (cable and system) and high parallel capacitance (magic box) you start to model a low-pass filter. That is, if the magicbox itself doesn't already throw some additional series inductance into the "loop" (get it? inducatnce? Loop? ha?)

Maybe it's just more glamorous to say "Power Factor Corrected" or whatever the slingline is, but it sure sounds to me like a second order low pass filter. Filter filter filter. And that's ok, I guess, as long as the knee frequency is high enough ... but even then a low pass filter will induce phase distortions that weren't characterized in the system before the magicbox was shoved in line.

All of this hocus pocus is comical. Power Factor Correction for the variable output of an audio amplifier. Correct the phase distortion between current and voltage. I just don't know where this silly stuff comes from.

To be fair, maybe I misunderstood something in your post - if I did, accept my apology. And if you like your MIT cables - God Bless and follow your bliss and may the Force be With You, I'm not about to tell you what should give you your kicks. But as far as I can tell from what I've read, seen, and now read from you - these boxes are filters, probably low-pass filters, which in and of themselves will introduce phase-shift, not correct it.

Again, I restate - if you've got a high rez audio rig, there's no reason to "correct" anything with exotic blackbox cables - just get good quality cables that don't generically modify the intended, already designed circuit of the amplifier and the speaker.

I have tried the MIT and transparent cables...the high end ones and NEVER liked them. As someone has said above, my kimbers were far superior sounding. I really wanted to keep them because of the "COOL" factor with the professional/expensive look of the network boxes but my ears could not break in to the sound.

Transparent cables sound downright "BLAND" and MIT sounds "THIN AND BRITTLE".

Finally...I have come to a conclusion that "BOXES ARE FOXES"

You do not have to agree with my observation but if you do a search on MIT and Transparent cables, look how many comes up and look at the highly depreciated prices. Must tell you something though???

all doubting Thomas's STILL sound the same

Unklecrusty: I am not defending MIT, Transparent, etc... I have no real experience with them nor do i feel the need to investigate them.

Having said that, all i can say is that changing the line length of ANY speaker cable will present the amplifier with a different feedpoint impedance. This in turn can play games with how it loads up, the correction circuitry, etc... If MIT, Transparent or for that matter Kimber, Goertz, Monster, etc... presents the amp with an impedance that it likes, it will work better.

The bottom line would be to hook up various cables to a system one by one and test them. One could feed various test signals into the system and check to see what produced the most linear loading at the amp and speaker's binding posts. I had intended to do this sometime in the near future just to see how measurable the differences really are. On top of that, i'm wondering how closely the waveform would equate to actual sound quality i.e. would a severely distorted waveform produce severely non-linear sound ??? I guess i'll have to wait and see. Sean
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As I replied to Abal, even parallel capacitance as a "power factor correction" will, together with the series inductance of the circuit (and perhaps even an inductor in the magic box) create a second order low pass filter - but maybe just maybe it works as you say it does, and maybe that is desireable.

IF that is the case ... why not just make add-on boxes with leads on them instead of making whole cables? Jack Bybee does this, Walker does this, there are a couple of aftermarket boxes that work in this gap - why not MIT and Transparent? They aren't selling cables, per se - they are selling cable-fixers. So why not fix a greater variety of cables with the magic boxes?

And if the magic box prevents reflected energy from returnining to the feedback loop of an amplifier, would it be safe to assume that they wouldn't have this effect with amplifiers such as zero-feedback SET types?

And cables that are THAT reactive are just poorly designed, IMHO. But as you say, "This explains why synergy is so critical when trying to optimize your setup, and why a particular cable set works differently when placed into different electrical environments. This is an unavoidable fact of life for any cable." - basically we understand each other in that these magicboxes cannot be optimized for all systems, but can fit only particular systems and this with only varying degrees of optimization depending upon how far from the original modeled system the system under test falls.