MIT Love 'em or Hate 'em

Thanks, Ozfly! It's good to know my work is being appreciated! There's nothing worse than having to suffer for your art...

I hate to tell "unclecrusty" that he is wrong due to his seeming all-knowingness in his story but here it is: If you read the MIT white papers, you will discover that there is no filtering involved in the MIT speaker cables. It is funny to see what kind of wives' tales people can come up with and firmly believe them. Perhaps he was referring to power conditioners that are installed before the power reaches the stereo but this is not the subject at hand.

The MIT network boxes are there to correct not the stereo, but the cables themselves. There is no denying the fact that all cables are fundamentally transmission lines and can be modeled as such. This modeling includes all the little nasties that many overlook like inductance and capaciatance. These last two directly induce phase delay between the current and voltage, known as power factor. Voltage and current are the ingrediants of sound - you screw them up and the result is botched. The MIT boxes realign the two and in so doing, correct the power factor and phase delay. This is assuming that the power amplifier supplies corrected it also on their end - otherwise the cables correct for that too. As an electrical engineer, I have observed pitiful responses from "high end" amps in the lab since the designer equates good sound with circuit simplicity and in doing so jeoperdizes its very existance, but that is a whole other story....

Anyone interested in the gory details may contact me directly in the interest of keeping others from getting bored. Bottom line is I love the sound of my MIT cables.

Arthur

The common misnomer that networked cables (MIT - Transparent) are filtered - is incorrect. The networks are paralleled across the conductors, not in series. Their purposes are (1) group delay compensation, as mentioned above and (2) to help absorb/attenuate reflected energy so as to prevent it reaching back to the amp, the amp's feedback then attempting to make erroneous corrections based upon those signal reflections. This also smooths out the detrimental effects of the inherent reactance charactaristics of cabling, ALL of which is reactive to some degree or another, making ALL cables equivelant to filters in some way, and thus interacting with the reactive characteristics of both the source & the load. 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. It is gratifying to see that at least *some* such as Dautch actually comprehend what is going on in that respect. Others who may install a component or cable into their existing rig (previously optimized for a different matchup) and then experience less than stellar results, are quick to blame the new device as a bad one, obviously an oversimplified & incorrect assumption.
In my particular case, my rig took to MIT cabling like a fish takes to water, realizing a lovely combination immediately, which only improved over a 30 day interval as the cables were further used (the breakin phenomenon). Bruce Brisson definitely knows what he's doing, just very misunderstood.

I've used MIT interconects in the past; and thought they were a good value for the money. About four years ago, when I first started upgrading my main audio system; I bought several sets of 2s and 3s from Audio Advisor during one of their MIT sales. At the time, they were a big improvement over the Monster Cable garbage I was using. I later moved on to Transparent MusicWave & MusicWave Plus ICs and speaker cables - and McIntosh electronics; and genuinely enjoy the set-up I have right now. (Though I'm going to try out some Cardas & Nordost ICs later this month!)
And I might add, that I'm currently still using some of those MIT 2s and 3s here in my media duplication business. They still sound pretty decent, and the connectors have held up quite well!

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.