The Mysterious Box Of The MIT Cable MITerminator 5

I recall my memory from my teenager age, when I was looking at the MIT cable advertisement in the Stereophile magazine, I believe it was mid 90's, the mysterious box is in line with the cables that makes me curious about the purpose of that box.

I was thinking it should be some magic or top-secret tuning equipment from the MIT engineer for speaker cables. My curiosity keeps rolling through my head until today, I have a chance to have it.

So let's take a look closer and let's find out the magic.

The cable I have here is MITerminator 5 edition. It is 2 meter length pair speaker cables.

After I checked their product line-up, this cable is not the top of their speaker cables, but I believe the general principal of the "secret" box should be the same.

Looking closer, the thickness of this cable is around 18 mm diameter. The greyish color makes the cable look dirty and old.

This cable have innovative design. The end-plug can swap with either banana plugs or spades. I think this feature is very useful and made the installation more practical to suit any equipment's.

I guess the introduction is enough and lets see what inside!

Opening up the "secret" box is easy. The plastic is easy to break due to the aging of the material.

It is easy to break, just like biscuit. Inside it you will find a lot of glue covering everything inside.

The glue is covering a small inductor which is now my curiosity become wilder.

Why put inductor in the cable?

So I am going deeper with it to see what purpose this inductor to the cable.

I detach the wiring from the inductor and find there are 4 cables inside the jacket, which one of them are in series with the inductor.

The inductor is iron core with the value is around 0.2 mH.

As we are know the inductor function in series is to cut the high frequency. It is common for the low-pass filter cross-over circuit but for the cable like this, is a rare sight.

The detail inside of this thick cable jacket are filled with nylon.

Then there are four cables consist of pair of 16 AWG and pair of 20 AWG. Their configuration are parallel on both polarity just like bi-wiring speaker system. One small wire with one big wire for each cable polarity.

One of the positive polarity of the small 20AWG wire is cut and connect to the inductor.

This principle remind me to baffle step compensation circuit which the cables will act as a resistor, parallel with the inductor. This might result in lowering the high frequency noise and improve the low-end response.

I could say the "secret" box is a tuning house from the MIT designer.

With this configuration, I believe not every system could get the benefit from it. Most of the time, it will coloring the original sound.

To make my explanation clearer, I make this cable schematic as shown bellow.

I also ripped out one cable end to see the cable configuration as well.

Since this post is become popular, I did further analysis for the inductor in here.

Disclaimer: Any statement and photos in this article are not allowed to copy or publish without written permission from the writer. Any injury or loss from following tips in this article is not under writer responsibility.